WO2007052954A1

WO2007052954A1 - Block copolymers containing perfluorocyclobutane rings and electrolyte membranes using the same

Info

Publication number: WO2007052954A1
Application number: PCT/KR2006/004513
Authority: WO
Inventors: Chong Kyu Shin; Bong Keun Lee; Jeong Hoon Kim; Bong Jun Chang; Soo Bok Lee; In Joon Park; Dong Kwon Kim; Kwang Won Lee; Jong Wook Ha; Kwang Han Kim; Dong Jin Kim; Min Chul Yoo
Original assignee: Lg Chem, Ltd.; Korea Research Institute Of Chemical Technology
Priority date: 2005-11-01
Filing date: 2006-11-01
Publication date: 2007-05-10
Also published as: KR20070047229A; KR100756457B1

Abstract

The present invention relates to a block copolymer comprising perfluorocyclobutane group, a process for preparing the same, and an electrolyte membrane comprising the same. The block copolymer comprising perfluorocyclobutane group according to the present invention can be easily prepared. And, the electrolyte membrane comprising the polymer has good proton conductivity and mechanical property; the distribution, position, and number of sulfonic acid group can be controlled, and the membrane properties are not decreased even though sulfonic acid group is increased. Thus, the present block copolymer can be used for a variety of membrane materials, especially electrolyte membrane of fuel cell.

Description

BLOCK COPOLYMERS CONTAINING PERFLUOROCY- CLOBUTANE RINGS AND ELECTROLYTE MEMBRANES

USING THE SAME

[1] TECHNICAL FIELD

[2] The present invention relates to a block copolymer comprising perfluorocy- clobutane ring, a process for preparing the same, and an electrolyte membrane comprising the same. Specifically, the present invention relates to a block copolymer comprising perfluorocyclobutane ring which can be easily and effectively prepared into membrane since the electrolyte membrane comprising the polymer has good proton conductivity and mechanical property; the distribution, position, and number of sulfonic acid group can be controlled; and the membrane properties are not decreased even though sulfonic acid group is increased; a process for preparing the same; and an electrolyte membrane and fuel cell comprising the same.

[3]

[4] BACKGROUND ART

[5] Fuel cell is an energy conversion system that converts chemical energy into electrical energy, and so has been vigorously studied as next generation energy source due to explosive demand increase of electricity, high energy efficiency, and environmental affinity of discharging less pollutant. Fuel cell can be classified by electrolyte material or operation temperature. In particular, polymer electrolyte membrane fuel cell (PEMFC) has various advantages in that it can be used for a small size of electric generation to provide both power and heat, has superior energy conversion and electric power density to other types of fuel cells, can be operated at a low temperature, and has stability to mechanical impact. Thus, PEMFC has received an attention as power source for automobile and electrical device.

[6]

[7] Only, such polymer electrolyte membrane also requires high ionic conductivity, durability on oxidation and reduction, and mechanical strength. Fuel cell membranes such as perfluorinated ion exchange membranes including Nafion™ of Du Pont and Aciplex™ of Asahi Chemical have been commercialized. However, the above perfluorinated polymer electrolyte membranes have disadvantages that the price is high though the performance is good, and the efficiency is decreased at 80 °C or more. Besides the above disadvantages, the above membranes also have a disadvantage of methanol crossover, i.e., methanol is effused from oxidation electrode to reduction electrode through the membrane when the membrane is used in the direct methanol fuel cell (DMFC). In order to solve the above disadvantage problems, various studies has been made to replace the perfluorinated membranes with non- fluorinated membranes or partially fluorinated membranes.

[8]

[9] U.S. Patent No. 6,559,237 describes a post-sulfonation process of partially fluorinated perfluorocyclobutane membrane as polymer electrolyte membrane. However, the post-sulfonation process has several limitations that the distribution, location, and number of sulfonic acid group of the polymer backbone is difficult to control, and the properties of electrolyte membrane are decreased by the increase of water content in the membrane, as sulfonic acid groups are increased.

[10] U.S. Patent No. 5,602,185 describes a preparation process for polymer electrolyte membrane by randomly copolymerizing partially fluorinated trifluorostyrene derivatives. However, this process also has several limitations that the preparation cost of monomer is very high since Pd catalyst is used in the process; the membrane has low mechanical property due to the rigid structure of polystyrene; the distribution, location, and number of sulfonic acid group of the polymer backbone is difficult to control; and the properties of electrolyte membrane are decreased by the increase of the water content in the membrane, as sulfonic acid groups are increased.

[11] U.S. Patent No. 6,090,895 describes a cross-linking process of sulfonated polymers, such as sulfonated polyetherketone, sulfonated polyethersulfone, sulfonated polystyrene, etc. However, it did not disclose an effective way to produce a volume of thin films by using the above cross-linked sulfonic acid polymer.

[12] EP Publication Gazette No. 1,113,517 A2 describes a block copolymer electrolyte membrane composed of blocks that have and do not have sulfonic acid. In this patent, a block copolymer composed of aliphatic block and aromatic block was sulfonated by using sulfuric acid, but this process has a problem that the location and number of sulfonic acid groups in the polymer backbone could not be controlled, and so the aliphatic polymer bond is chemically broken down during the sulfonation.

[13] US Patent Publication No. 2004-186262 describes a preparation method for a multi block copolymer electrolyte membrane comprising hydrophobic block and hydrophilic block that consisted of hydrocarbon, in turn. In the method, a copolymer in the form of -SO K was converted into -SO Cl by using thionylchloride (SOCl ), in producing thin film, due to low solubility of the multi block copolymer, to provide a polymer thin film with proton conductivity. However, this method has some problems that the production process is complicated, thionylchloride is a toxic material, and the mechanical integrity of the polymer thin film is far behind the required level at the time of operating the fuel cell.

[14] [15] DISCLOSURE OF THE INVENTION

[16] The present inventors have studied to solve the above problems in the conventional polymer, and discovered that hydrophilic and hydrophobic oligomers can be easily prepared by using a hydrophilic monomer having perfluorovinyloxy group at both ends, and a non-sulfonated hydrophobic monomer, specifically that a sulfonated multi- block copolymer can be easily prepared by synthesizing block oligomer each from high sulfonization activity monomer having perfluorovinyloxy group at both ends and low sulfonization activity monomer having perfluorovinyloxy group at both ends, and by post-sulfonating such prepared block oligomer, to complete the present invention.

[17]

[18] Therefore, one object of the present invention is to provide a chemically stable block copolymer which can be easily prepared, and has good proton conductivity and mechanical property, especially a post-sulfonated block copolymer, and a method for preparing the same.

[19] Another object of the present invention is to provide an electrolyte membrane comprising the above block copolymer, characterized in that the distribution, position, and number of sulfonic acid group can be controlled, and has good proton conductivity, mechanical property, and chemical stability, and the membrane properties are not decreased even though sulfonic acid group is increased, and a process for preparing the same.

[20] And, another object of the present invention is to provide a fuel cell comprising the above electrolyte membrane.

[21]

[22] BRIEF DESCRIPTION OF DRAWINGS

[23]

[24] FIGS 1 and 2 represent graphs showing the proton conductivity of the multi-block copolymer containing perfluorocyclobutane rings according to one embodiment of the present invention.

[25]

[26] BEST MODE FOR CARRYING OUT THE INVENTION

[27]

[28] The present invention provides a block copolymer (I), comprising a repeated unit represented by the following formula (1) and a repeated unit represented by the following formula (4):

(-R-P-Q-P-) (1)

(-R"-P-Q-P-) (4)

[29] wherein, [30] -P- is each independently selected from the group consisting of -O-, -S-, -SO-, SO -

, -CO-, -NH-, -NR -, and -R -, wherein R is alkyl or aryl of 1 ~ 25 carbon atoms, and R is alkylene or arylene of 1 ~ 25 carbon atoms,

[31] -Q- is each independently l,2-perfluorocyclobutylene(C F ),

4 6

[32] R is aromatic group which is unsubstituted or substituted with one or more inert groups which do not induce other chemical reaction in forming the group -Q-,

[33] R" is aromatic group which has one or more benzene rings substituted with one or more -PO H or -SO H.

3 2 3

[34] In the above formula, it is preferable that each -P- represents -O- or -S, R represents alkyl of 1 ~ 3 carbon atoms, or R is alkylene of 1 ~ 3 carbon atoms.

[35] Also, it is preferable that the benzene rings are linked directly or by -O-, -S-, -(CH

)-, -(C(O))-, -(S(O)J 2 -, -(-P(O))-, -(Si(CH 3 )2 J-, -(C(CH 3)2)-, -(C(CFJ 3 2)- or -(Si(C 6 H5) >2 when R or R" has two or more benzene rings.

[36]

[37] The above block copolymer (I) according to the present invention can be prepared by polymerization of a hydrophobic monomer [formula (I)] which does not have acid substituents, and a hydrophilic monomer [formula (4)] which has acid substituents, and converting the acid substituents into acid group. Thus, the present block copolymer (I) has the structure that the hydrophobic block which can sustain the mechanical integrity of the thin film and the hydrophilic block which can endow the ionic conductivity to the thin film are chemically linked in turn.

[38]

[39] The substituent R of the hydrophobic block is not specifically limited, but may be one or more aromatic compounds selected from the following group:

[41] More preferable substituent R is one or more aromatic compounds selected from the following group:

[42] The substituent R" of the hydrophobic block is not specifically limited, but may be aromatic compound which is substituted with one or more -PO H or -SO H on

3 2 3 benzene ring of one or more compound R' selected from the following group:

[43] wherein A is -NO or -CF .

2 3 [44] [45] More preferable substituent R" is aromatic compound which is substituted with one or m noorree --PPOO H

3 H o 2 orr --SSO H on benzene ring of one or more compound R' selected from the following group:

[46] It is preferable that the block copolymer according to the present invention comprises a repeated unit represented by the following formula (5):

[47] wherein R and R" are each as defined above, and [48] n and m are independently an integer of 1 to 10,000. [49] [50] Also, the present invention provides a block copolymer (II), comprising a block containing aromatic compound having high sulfonization activity, and a block containing aromatic compound having low sulfonization activity. [51] In the above block copolymer, the preferable substituent R of the repeated unit represented by the above formula (1) is one or more aromatic compounds having low sulfonization activity selected from the following group:

[52] More preferable substituent R is aromatic compound selected from the following group:

[53] Also, the preferable substituent R " of the repeated unit represented by the above formula (4) is aromatic compound which is substituted with one or more -SO H on benzene ring of one or more compound R' having high sulfonization activity selected from the following group:

[54] More preferable substituent R" is aromatic compound which is substituted with one or more -SO H on benzene ring of one or more compound R' selected from the following group:

[55] The above post-sulfonated block copolymer (II) according to the present invention can be prepared by polymerization of a monomer or a block oligomer which has high sulfonization activity, and a monomer or a block oligomer which has low sulfonization activity, and then post-sulfonating the copolymer. Thus, the present block copolymer (II) has the structure that the block having low sulfonization activity which can sustain the mechanical integrity of the thin film, and the block having high sulfonization activity which can endow the ionic conductivity to the thin film are chemically linked in turn.

[56]

[57] The block copolymer according to the present invention is preferable to have 500 to 500,000 (g/mol) of weight average molecular weight of the block comprising the repeated unit represented by the formula (1), and 500 to 500,000 of weight average molecular weight of the block comprising the repeated unit represented by the formula (4). If each weight average molecular weight of the block is less than 500 (g/mol), the block's size is small, and so it is difficult to form a block copolymer, or the mechanical integrity of the prepared thin film may be decreased. If each weight average molecular weight of the block is more than 500,000 (g/mol), the block's size is big, and so it is difficult to control the block's size.

[58]

[59] Also, the present invention provides a process for preparing the block copolymer

(I). The above preparation process can be classified into, i) a preparation process by using a hydrophilic block and a hydrophobic block, ii) a preparation process by using a hydrophobic block and a hydrophilic monomer, and iii) a preparation process by using a hydrophobic monomer and a hydrophilic block.

[60] Specifically, the process i) for preparing the block copolymer by using a hydrophilic block and a hydrophobic block comprises:

[61] a) a step of polymerizing aromatic monomer represented by the following formula

(6):

F₂C=FC-P-R-P-CF=CF₂ (6),

[62] wherein P and R each are as defined above, which has perfluorovinyloxy group at both ends, [63] to produce a hydrophobic block oligomer represented by the following formula (7): F₂C=FC-P-(-R.-P-Q-P-)_n'-R-P-CF=CF₂ (7),

[64] wherein P, Q and R are each as defined above, and n' is an integer of 1 to 10,000;

[65] b) a step of polymerizing aromatic monomer represented by the following formula

(8):

F₂C=FC-P- IT-P-CF=CF₂ (8)

[66] wherein P is as defined above, and R'" is aromatic group having one or more benzene rings which are substituted with one or more acid substituent groups selected from the group consisting of -SO Cl, -SO F, -SO ^"M⁺, -P(O)(OA) , -PO HM⁺ and -PO

^2"2M\ wherein A is alkyl of 1 ~ 4 carbon atoms, and M is alkali metal , which has acid substituent group and perfluorovinyloxy group at both ends,

[67] to produce a hydrophilic block oligomer represented by the following formula (9):

F₂C=FC-P-(-R-P-Q-P-)m- R'"-P-CF=CF₂ (9),

[68] wherein P and Q are each as defined in claim 1, R is as defined above, and m' is an integer of 1 to 10,000; [69] c) a step of reacting the hydrophobic block oligomer prepared in the step a) and the hydrophilic block oligomer prepared in the step b) to produce an acid substituent block copolymer represented by the following formula (10):.

-(-R-P-Q-P-)n-(-R"'-P-Q-P-)m- (10)

[70] wherein P, Q, R'" and R are each as defined above, and n and m each are an integer of 1 to 10,000; and [71] d) a step of converting the acid substituent group (R'") of the acid substituent block copolymer prepared in the step c) into acid group (R") wherein R' is as defined above. [72] [73] Also, the process ii) for preparing the block copolymer by using a hydrophobic block and a hydrophilic monomer comprises: [74] a) a step of polymerizing aromatic monomer represented by the following formula

(6):

F₂C=FC-P-R-P-CF=CF₂ (6),

[75] wherein P and R are each as defined above, which has perfluorovinyloxy group at both ends, [76] to produce a hydrophobic block oligomer represented by the following formula (7):

F₂C=FC-P-(-R-P-Q-P-)_n'-R-P-CF=CF₂ (7),

[77] wherein P, Q and R are each as defined above, and n' is an integer of 1 to 10,000;

[78] b) a step of polymerizing aromatic monomer represented by the following formula (8): F₂C=FC-P- IT-P-CF=CF₂ (8)

[79] wherein P is as defined in claim 1, and R'"

[80] is as defined above , which has acid substituent group and perfluorovinyloxy group at both ends, [81] with the hydrophobic block oligomer prepared in the step a) to produce an acid substituent block copolymer represented by the following formula (10):.

-(.R.p.Q-P-)_n-(-R--P-Q-P-)_m- (10),

[82] wherein P, Q and R are each as defined in claim 1, R'" is as defined above, and n and m each are an integer of 1 to 10,000; and [83] c) a step of converting the acid substituent group (R'" ) of the acid substituent block copolymer prepared in the step b) into acid group (R") wherein R' is as defined above. [84] Further, the preparation process iii) by using a hydrophobic monomer and a hy- drophilic block comprises: [85] a) a step of polymerizing aromatic monomer represented by the following formula

(8):

F₂C=FC-P- R'"-P-CF=CF₂ (8),

[86] wherein P and R'" are as defined above, which has acid substituent group and perfluorovinyloxy group at both ends, [87] to produce a hydrophilic block oligomer represented by the following formula (9):

F₂C=FC-P-(-R-P-Q-P-)m- IT-P-CF=CF₂ (9),

[88] wherein P, R'" and Q are each as defined above, and m' is an integer of 1 to 10,000;

[89] b) a step of polymerizing aromatic monomer represented by the following formula

(6):

F₂C=FC-P-R-P-CF=CF₂ (6),

[90] wherein P and R are each as defined above, which has perfluorovinyloxy group at both ends, [91] with the hydrophilic block oligomer prepared in the step a) to produce an acid substituent block copolymer represented by the following formula (10):.

-(-R-P-Q-P-)_n-(-R'"-P-Q-P-)m- ( 10)

[92] wherein P, Q, R'" and R are each as defined above, and n and m each are an integer of 1 to 10,000; and [93] c) a step of converting the acid substituent group (R'") of the acid substituent block copolymer prepared in the step b) into acid group (R") wherein R' is as defined above. [94] [95] In the above preparation process, the acid substituent group (R'") may be converted into acid group (R") by adding acid solution into the acid substituent block copolymer when R" comprises the acid substituent group of -SO ^"M⁺, -PO HM⁺ or -PO ^"2M⁺. Or, the acid substituent group (R'") may be converted by adding the acid substituent block copolymer into acid or base solution to hydrolyze the acid substituent block copolymer, followed by treating with acid solution when R'" comprises the acid substituent group of -SO Cl, -SO F or -P(O)(OA) .

[96] [97] Hereinafter, the process for preparing the block copolymer (I) according to the present invention will be more specifically explained by using the following reaction scheme (1):

(9)

(7)+(9) or F F F F

(7)+(8) -R-O-C-C-O- K-O-C-C-C or F₂C-CF₂ F₂C-CF₂

(6)+(9)

(10)

Reaction Scheme (1)

[98] As shown in the above reaction scheme (1), the block oligomer compound (7) and compound (9) can be prepared from monomer compound (6) and compound (8), respectively. The multi-block copolymer (10) having acid substituent can be prepared by mixing the hydrophobic block oligomer compound (7) and the hydrophilic block oligomer compound (9); by mixing the hydrophobic block oligomer compound (7) and the hydrophilic monomer compound (8); or by mixing the hydrophobic monomer compound (6) and hydrophilic block oligomer compound (9). Meanwhile, perfluorocy- clobutane ring is formed in a melting or solution state by heating under inert gas such as nitrogen, or argon atmosphere, for 30 minutes to 48 hours, to initiate polymerization reaction. A suitable reaction temperature is 80°C or more, preferably 130°C or more, because cyclization reaction is not carried out, or the reaction velocity is very low, below 80°C. [99] When the reaction is carried out in the solution, organic solvent is not specifically limited as long as it can dissolve reactant and product, but it is preferable to use polar aprotic solvent such as dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), or dimethylaectamide (DMAC); or a solvent having more than 130°C of melting point such as diphenylether (DPE), or 1,3,5-trimethylbenzene.

[100] In the above preparation process, when the hydrophobic monomer compound (6) and the hydrophilic block compound (9) form the copolymer, m' is 2 or more; when the hydrophobic block compound (7) and the hydrophilic monomer compound (8) form the copolymer, n' is 2 or more; and when the hydrophobic block compound (7) and the hydrophilic block compound (9) form the copolymer, each of n' and m' is 2 or more.

[101] The multi-block copolymer prepared by the above process has better mechanical property than conventional homopolymer or random copolymer having perfluorocy- clobutane; and can control the distribution, position and number of sulfonic acid group, and the membrane can be effectively prepared since the membrane properties are not decreased even though sulfonic acid group is increased.

[102] [103] The present invention also relates to a block copolymer (III) comprising a repeated unit represented by the following formula (1) and a repeated unit represented by the following formula (2):

(-R-P-Q-P-) (1)

(-R'-P-Q-P-) (2)

[104] wherein,

[105] -P- is each independently selected from the group consisting of -O-, -S-, -SO-, SO -

, -CO-, -NH-, -NR -, and -R -, wherein R is alkyl or aryl of 1 ~ 25 carbon atoms, and R is alkylene or arylene of 1 ~ 25 carbon atoms, [106] -Q- is each independently l,2-perfluorocyclobutylene(C 4 F 6 ),

[107] R is one or more aromatic compounds having low sulfonization activity selected from the following group:

[108] R' is one or more aromatic compounds having high sulfonization activity selected from the following group:

[109] wherein A is -NO or -CF .

2 3

[HO]

[111] More preferable block copolymer (HI) comprises a repeated unit represented by the following formula (3):

F F F F -R-O- C— C— i - -R'-O-C— C— O-

I I F₂C-CF₂ F₂C-CF₂ m

(3)

[112] wherein, R and R' are each as defined above, and [113] n and m are each independently an integer of 1 to 10,000. [114] [115] The above block copolymer (II) according to the present invention is characterized in that the block oligomer having low sulfonization activity represented by the above formula (1) and the block oligomer having high sulfonization activity represented by the above formula (2) are chemically linked in turn. Therefore, the distribution, position and number of sulfonic acid group in the polymer backbone can be easily controlled by adjusting the values of n and m in the above formula (3).

[116] [117] The present invention also relates to a process for preparing the block copolymer (III) by, A) polymerizing the block oligomer having high sulfonization activity and the block oligomer having low sulfonization activity, B) by polymerizing the block oligomer having low sulfonization activity and the monomer having high sulfonization activity with perfluorovinyloxy group at both ends, or C) by polymerizing the block oligomer having high sulfonization activity and the monomer having low sulfonization activity with perfluorovinyloxy group at both ends. [118] [119] Specifically, the process A) for preparing the block copolymer (III) according to the present invention comprises: [120] a) a step of polymerizing aromatic monomer represented by the following formula

(6):

F₂C=FC-P-R-P-CF=CF₂ (6),

[121] wherein P and R are each as defined above, which has low sulfonization activity and perfluorovinyloxy group at both ends, [122] to produce a block oligomer having low sulfonization activity represented by the following formula (7):

F₂C=FC-P-(-R-P-Q-P-)_n'-R-P-CF=CF₂ (7),

[123] wherein P, Q and R are each as defined above, and n' is an integer of 1 to 10,000;

[124] b) a step of polymerizing aromatic monomer represented by the following formula

(11):

F₂C=FC-P-R'-P-CF=CF₂ (11)

[125] wherein P and R' are each as defined above, which has high sulfonization activity and perfluorovinyloxy group at both ends, [126] to produce a block oligomer represented having high sulfonization activity by the following formula (12):

F₂C=FC-P-(-R'-P-Q-P-)_m-R'-P-CF=CF₂ (12),

[127] wherein P, Q and R' are each as defined above, and m' is an integer of 1 to 10,000; and

[128] c) a step of polymerizing the block copolymer prepared in the step a) having low sulfonization activity and the block copolymer prepared in the step b) having high sulfonization activity.

[129]

[130] The process B) for preparing the block copolymer (III) according to the present invention comprises:

[131] a) a step of polymerizing aromatic monomer represented by the following formula

(6):

F₂C=FC-P-R-P-CF=CF₂ (6), [132] wherein P and R are each as defined above, which has low sulfonization activity and perfluorovinyloxy group at both ends, [133] to produce a block oligomer having low sulfonization activity represented by the following formula (7):

F₂C=FC-P-(-R-P-Q-P-)n-R-P-CF=CF2 (7),

[134] wherein P, Q and R are each as defined above, and n' is an integer of 1 to 10,000; and [135] b) a step of polymerizing the block copolymer prepared in the step a) having low sulfonization activity and aromatic monomer represented by the following formula

(11):

F₂C=FC-P-R-P-CF=CF₂ (11),

[136] wherein P and R' are each as defined above, which has high sulfonization activity and perfluorovinyloxy group at both ends. [137] The process C) for preparing the block copolymer (III) according to the present invention comprises: [138] a) a step of polymerizing aromatic monomer represented by the following formula

(11):

F₂C=FC-P-RZ-P-CF=CF₂ (11)

[139] wherein P and R' are each as defined above, which has high sulfonization activity and perfluorovinyloxy group at both ends, [140] to produce a block oligomer having sulfonization activity represented by the following formula (12):

F₂C=FC-P-(-R'-P-Q-P-)_m-R'-P-CF=CF₂ (12),

[141] wherein P, Q and R' are each as defined above, and m' is an integer of 2 to 10,000; and [142] b) a step of polymerizing the block copolymer prepared in the step a) having high sulfonization activity and aromatic monomer represented by the following formula (6):

F₂C=FC-P-R-P-CF=CF₂ (6),

[143] wherein P and R are each as defined above, which has low sulfonization activity and perfluorovinyloxy group at both ends. [144] [145] Hereinafter, the process for preparing the block copolymer (I) according to the present invention will be more specifically explained by using the following reaction scheme (2):

(7)

(12)

(7)+(12)

F F F F

(V -R-O-C-C- R'-O— C-C-C or d D

F₂C-CF₂ F₂C-CF₂

(6)+(12)

(III )

Reaction Scheme (2)

[146] As shown in the above reaction scheme (2), the block oligomer compound (7) and compound (12) can be prepared from monomer compound (6) and compound (11), respectively. The block copolymer (HI) having no sulfonic acid group can be prepared by mixing the monomer compound (6) and the block oligomer compound (12); by mixing the block oligomer compound (7) and the monomer compound (11); or by mixing the block oligomer compound (7) and block oligomer compound (12). Meanwhile, perfluorocyclobutane ring is formed in a melting or solution state by heating under inert gas such as nitrogen, or argon atmosphere, for 30 minutes to 72 hours, to initiate polymerization reaction. A suitable reaction temperature is from 80°C to 300°C, preferably 130°C or more. If the reaction temperature is less than 80°C, cy- clization reaction is not carried out, or the reaction velocity is very low. If the reaction temperature is more than 300°C, the compounds may be decomposed.

[147] When the reaction is carried out in the solution, organic solvent is not specifically limited as long as it can dissolve reactant and product, but it is preferable to use polar aprotic solvent such as dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), or dimethylaectamide (DMAC); or a solvent having 130°C or more of melting point such as diphenylether (DPE), or 1,3,5-trimethylbenzene.

[148] [149] The present invention also relates to a process for preparing the post-sulfonated block copolymer (II), comprising the step of sulfonating the block copolymer prepared by the above preparation processes A) to C).

[150] The above sulfonating step may use a method known to the art, and any post- sulfonating agent which can introduce -SOH into the polymer can be unlimitedly used. It is preferable to use a sulfonating agent selected from the group consisting of chlorosulfonic acid, sulfur trioxide, sulfuric acid, fuming sulfuric acid, and acyl sulfate.

[151]

[152] The present invention also relates to an electrolyte membrane comprising the block copolymer according to the present invention. The above electrolyte membrane can be fabricated into all types of membranes known to the art. For example, the electrolyte membrane may be flat sheet membrane, hollow fiber membrane, composite membrane, or tube membrane. The electrolyte membrane prepared by the present invention has better mechanical properties than conventional homopolymer or random copolymer having perfluorocyclobutane, and can control the distribution, position and number of sulfonic acid group, and the membrane properties are not decreased even though sulfonic acid group is increased.

[153]

[154] The present invention also provides a process for preparing electrolyte membrane.

The process may be exemplified by the process (A) using the acid substituent block copolymer of formula (10), and the process (B) using the block copolymer (I) or (III), according to the present invention.

[155]

[156] The above process (A) comprises a step of melting the acid substituent block copolymer represented by the following formula (10) or dissolving the acid substituent block copolymer represented by the following formula (10) with organic solvent:

-(-R-P-Q-P-)_n-(-R'"-P-Q-P-)_m- (10),

[157] wherein P, Q, R, R'", n and m are each as defined in the above formula (10),

[158] to prepare polymeric membrane; and

[159] a step of converting the acid substituent group (R'" ) into acid group (R") wherein

R' is as defined above .

[160] The above process (B) comprises,

[161] a) a step of dissolving the block copolymer (I) or (III) with organic solvent;

[162] b) a step of coating the polymer solution on a substrate to form a film; and

[163] c) a step of drying the formed film.

[164]

[165] Hereinafter, the above processes (A) and (B) will be more specifically explained.

[166] In the process (A), polymeric solution is prepared by dissolving the acid substituent polymer of the above formula (10) with organic solvent. The film is formed by membrane-coating the prepared polymeric solution onto the surface of the solid substrate or the porous polymer substrate which is used for a membrane coating process known to the art, such as glass plate, metal, ceramic, polysulfone, or polyetheramide. The polymeric membrane is prepared by drying the above formed film at the temperature range of 50°C ~ 250°C for 10 minutes ~ 24 hours under the atmospheric pressure or vacuum.

[167] Among the polymeric membranes prepared above, the polymeric membranes wherein the acid substituent group is -SO Cl, -SO F or -P(O)(OA) can be prepared by adding the membrane into acid or base solution for hydrolysis, and then treating the membrane with acid solution. In this case, it is preferable to use aqueous solution which does not dissolve the above membrane and comprises acid or base as the above acid or base solution. Also, the polymeric membranes wherein the acid substituent group is -SO ^"M⁺, -PO HM⁺ or -PO ^2"2M⁺ can be prepared by treating the membrane with acid solution.

[168]

[169] In the above process (B), polymeric solution is prepared by dissolving the post- sulfonated block copolymer of the present invention with organic solvent. The organic solvent is not specifically limited as long as it cannot induce the chemical reaction and can dissolve the above polymer. The preferable examples of the organic solvent are dimethylsulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), or dimethylaectamide (DMAC). The film is formed by coating the prepared polymeric solution onto the surface of the substrate which is used in a membrane coating process known in the art. The above substrate is not specifically limited, and solid substrate such as glass plate, metal or ceramic; or porous polymer substrate such as polysulfone or polyetheramide may be used. The polymeric membrane is prepared by drying the above formed film at the temperature range of 50°C ~ 250°C for 10 minutes ~ 48 hours under the atmospheric pressure or vacuum.

[170]

[171] The present invention also relates to a fuel cell comprising the electrolyte membrane according to the present invention. The preferable fuel cell is polymer electrolyte membrane fuel cell or direct methanol fuel cell. Besides the above fuel cell, the electrolyte membrane according to the present invention can be widely used for ion exchange membrane, dehumidifying membrane, or humidifying membrane.

[172]

[173] Hereinafter, the present invention will be explained more specifically in the following examples, but is not limited thereby in any way.

[174]

[175] Example 1

[176] I) Preparation of biphenyl type of hydrophobic block oligomer (compound 6- 1)

[ 177] A. Preparation of 4,4'-Bis(2-bromotetrafluoroethoxy)biphenyl

[178] Anhydrous DMSO of 700 mL and NaH of 10.56 g(0.44 mol) were poured into a round bottom flask of 2000 ml under the nitrogen atmosphere, followed by agitation, and 4,4'-biphenol of 37.20 g(0.20 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetra fluoroethane of 114.40 g(0.44 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35°C, and the mixture was stirred for 1 day. The reactant was mixed with water to extract diethylether, and thus dried product was separated and purified by normal hexane through a column including silica gel.

[179] ^λ H-NMR (CDCl₃, δ in ppm): 7.31 (d), 7.58 (d), 19F-NMR (CDC13, δ in ppm): -

68.5 (s), -86.4 (s).

[180]

[181] B . Preparation of 4,4'-Bis(trifluorovinyloxy)biphenyl ( compound 6- 1 )

[ 182] 4,4'-bis(2-bromotetrafluoroethoxy)biphenyl of 54.40 g(0.10 mol) and zinc powder of 19.60 g(0.30 mol) were added into anhydrous CH CN of 300 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. Thus dried product was separated and purified by normal hexane through a column including silica gel.

[183] ^λ H-NMR (CDCl₃, δ in ppm): 7.18 (d), 7.54 (d), 19F-NMR (CDCl₃, δ in ppm): -

119.9 (dd), -126.7 (dd), -134.9 (dd).

[184]

[185] C. Preparation of hydrophobic block oligomer compound (7-1)

[186] Under the nitrogen atmosphere, 4,4'-bis(trifluorovinyloxy)biphenyl was heated at

170°C for 4 hours, and was slowly quenched to room temperature.

[ 187] GPC (polystyrene column) Mn 3,000 (g/mol).

[188]

[189] 2) Preparation of biphenyl type of hydrophilic block oligomer (compound 9-1)

[190] A. Preparation of 4,4'-bis(2-bromotetrafluoroethoxy)-biphenyl-3,3'-disulfonyl chloride

[191] A round bottom flask of 1000 mL was put into ice bath, and 4,4'-bis(2-bromotetra fluoroethoxy)biphenyl of 54.40 g(0.10 mol) and CHCl of 200 mL were mixed in the flask. Chlorosulfonic acid of 400 g was slowly added thereto dropwise under the nitrogen atmosphere. After 12 hours, the reaction solution was poured into ice water of 2000 mL, and the organic layer was separated and washed with ice water several times, followed by drying. The dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel.

[192] ^λ H-NMR (CDCl₃, δ in ppm): 7.76 (d), 7.97 (d), 8.29 (s), 19F-NMR (CDCl₃, δ in ppm): -68.4 (s), -85.9 (s). [194] B. Preparation of 4,4'-bis(2-bromotetrafluoroethoxy)-biphenyl-3,3'-disulfonyl fluoride

[195] Under the nitrogen atmosphere, dried CH CN of 200 mL,

4,4'-bis(2-bromotetrafluoroethoxy)-biphenyl-3,3'-disulfonyl chloride of 37.10 g(0.05 mol), and NaF of 21.80 g(0.38 mol) were poured into a round bottom flask of 500 mL, and the mixture was refluxed. After two days, the reactant was filtered with filter paper, and the filtrate was washed with water, and dried under vacuum. The dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel.

[196] ^λ H-NMR (CDCl₃, δ in ppm): 7.76 (d), 7.99 (d), 8.27 (s), 19F-NMR (CDCl₃, δ in ppm): 62.0 (s), -68.8 (s), -86.1 (s).

[197]

[198] C. Preparation of 4,4'-bis(trifluorovinyloxy)-biphenyl-3,3'-disulfonyl fluoride ( compound 8-1)

[199] 4,4'-Bis(2-bromotetrafluoroethoxy)-biphenyl-3,3'-disulfonyl fluoride of 20.00 g(28.00 mmol), copper(I) chloride of 5.60 g(0.05 mol), and zinc powder of 5.90 g(0.09 mol) were poured into anhydrous CH CN of 150 mL, and the mixture was agitated and heated for reflux. After 4 days, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. The dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel.

[200] ^λ H-NMR (CDCl₃, δ in ppm): 7.76 (d), 7.98 (d), 8.23 (s), 19F-NMR (CDCl₃, δ in ppm): 62.6 (s), -115.5 (dd), -122.1 (dd), -135.1 (dd).

[201]

[202] D. Preparation of hydrophilic block oligomer compound ( compound 9-1)

[203] Under the nitrogen atmosphere, 4,4'-bis(trifluorovinyloxy)-biphenyl-3,3'-disulfonyl fluoride was heated at 160 °C for 4 hours, and was slowly quenched to room temperature.

[204] GPC (polystyrene column) Mn 2,100 (g/mol).

[205]

[206] 3): Preparation of biphenyl type of multi-block copolymer ( compound 10-1) and electrolyte membrane

[207] Under the nitrogen atmosphere, the above compound 6-1 of hydrophobic block oligomer and the above compound 9-1 of hydrophilic block oligomer were mixed in the weight ratios of 5: 1, 10: 1, and 20: 1, and the mixture was heated at 250°C for 5 hours and slowly quenched to room temperature. The polymer obtained therefrom was dissolved with DMAc, and thus obtained solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-1). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO to hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 1.5 (g/dl) )^" \ 1.2 (g/dl) )^"\ and 1.3 (g/dl) )^"\ respectively.

[208] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution on the glass plate was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[209]

[210] Example 2

[211] Three kinds of acid substituent polymers ( compound 10-1 ) prepared in the

Example 1 was melted and cast on a glass plate. The thickness of the copolymer solution on the glass plate was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare polymeric membrane having a thickness of 50 ~ 120 D . The above polymeric membrane was poured into K CO aqueous solution (10 wt%) for 1 day for hydrolysis, and treated with cone. HCl aqueous solution and distilled water to prepare multi-block copolymer electrolyte membrane.

[212]

[213] Example 3

[214] 1) Preparation of fluorene type of hydrophobic block oligomer (compound 7-2)

[215] A. Preparation of 9,9-Bis- { 4-(2-bromotetrafluoroethoxy)-phenyl } fluorene

[216] Anhydrous DMSO of 1000 mL and NaH of 10.56 g (0.44 mol) were poured into a round bottom flask of 2000 ml under the nitrogen atmosphere, followed by agitation, and 9,9-bis(4'-hydroxyphenyl)fluorene of 70.10 g (0.20 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 114.40 g(0.44 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35°C, and the mixture was stirred for 1 day. The reactant was mixed with water to extract dieth ylether, and thus dried product was separated and purified by normal hexane through a column including silica gel.

[217]

[218] B. Preparation of 9,9-bis(4-trifluorovinyloxyphenyl)fluorine (c ompound 6-2)

[219] 9,9-bis-[4-(2-bromotetrafluoroethoxy)-phenyl]fluorene of 70.80 g(0.10 mol) and zinc powder of 19.60 g (0.30 mol) were added into anhydrous diglyme of 500 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. The dried product was separated and purified by normal hexane through a column including silica gel.

[220]

[221] C. Preparation of hydrophobic block oligomer compound (7-2)

[222] Under the nitrogen atmosphere, 9,9-bis(4-trifluorovinyloxyphenyl)fluorene of

10.00 g was dissolved with diphenyloxide of 50.00 g, and the solution was heated at 170°C for 4 hours, and was slowly quenched to room temperature.

[223] GPC (polystyrene column) Mn 3,100 (g/mol).

[224]

[225] 2^*): Preparation of fluorene type of hydrophilic block oligomer (compound 9-2 )

[226] A. Preparation of

9,9-bis-{4-(2-bromotetrafluoroethoxy)phenyl}fluorene-2,7-disulfonic acid, and sodium salt

[227] A round bottom flask of 1000 mL was put into ice bath, and 9,9-bis-[4-(2- bro- motetrafluoroethoxy)-phenyl]fluorene of 70.80 g(0.10 mol) and CHCl of 200 mL were mixed in the flask. Chlorosulfonic acid of 400 g was slowly added thereto dropwise under the nitrogen atmosphere. After 12 hours, the reaction solution was poured into ice water of 2000 mL, and organic layer formed therefrom was separated and washed with ice water. 10 wt% Na CO aqueous solution was poured thereto, and the mixture was stirred for 1 day, followed by drying. The dried product was re- crystallized with acetone.

[228]

[229] B. Preparation of 9,9-bis-(4-trifluorovinyloxyphenyl)fluorene-2,7-disulfonic acid, and sodium salt ( compound 8-2)

[230] 9,9-bis-[4-(2-bromotetrafluoroethoxy)phenyl]fluorene-2,7-disulfonic acid, sodium salt of 27.40 g(0.03 mol), copper(I) chloride of 5.60 g(0.05 mol), and zinc powder of 5.90 g (0.09 mol) were poured into anhydrous CH CN of 150 mL. The mixture was agitated and heated for reflux. After 4 days, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. The dried product was recrystallized with acetone.

[231]

[232] C. Preparation of hydrophilic block oligomer compound (9-2)

[233] 9,9-bis-[4-(2-bromotetrafluoroethoxy)phenyl]fluorene-2,7-disulfonic acid, and sodium salt of 10.00 g were poured into NMP of 50 mL. Under the nitrogen atmosphere, the mixture was heated at 160 °C for 4 hours, and was slowly quenched to room temperature. [234] GPC (polystyrene column) Mn 3,400 (g/mol).

[235]

[236] 3): Preparation of fluorene type of multi-block copolymer and electrolyte membrane

[237] The hydrophobic block oligomer (compound 7-2) and the hydrophilic block oligomer (compound 9-2) were mixed in the weight ratios of 5:1, 10:1, and 20:1, and the mixture was poured into NMP (20 wt%). Under the nitrogen atmosphere, the mixture was heated at 200°C for 1 day and slowly quenched to room temperature. The polymer solution obtained therefrom was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the Compound (10-2). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO to hydrolysis for 1 day. The product obtained therefrom was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 0.9 (g/dl) )- \ 1.0 (g/dl) )^'\ and 1.1 (g/dl) )^'\ respectively.

[238] The polymer obtained above was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[239]

[240] Example 4

[241] 1): Preparation of phosphine oxide type hydrophobic block oligomer (compound

7-3)

[242] A. Preparation of bis{4-(2-bromotetrafluoroethoxy)phenyl}phenylphosphine oxide

[243] Anhydrous DMSO of 700 mL and NaH of 10.56 g(0.44 mol) were poured into a round bottom flask of 2000 ml under the nitrogen atmosphere, followed by agitation, and bis(4-hydroxyphenyl)phenylphosphine oxide of 62.00 g(0.20 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 114.40 g(0.44 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35°C, and the mixture was stirred for 1 day. The reactant was mixed with water to extract ethylacetate, and thus dried product was separated and purified by normal hexane through the column including silica gel.

[244]

[245] B. Preparation of bis(4-trifluorovinyloxyphenyl)phenylphosphine oxide ( compound 6-3)

[246] Bis[4-(2-bromotetrafluoroethoxy)phenyl]phenylphosphine oxide of 66.80 g(0.10 mol), and zinc powder of 19.60 g(0.30 mol) were added into anhydrous CH CN of 500 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. The dried product was separated and purified by normal hexane through a column including silica gel.

[247]

[248] C. Preparation of hydrophobic block oligomer compound (7-3)

[249] Under the nitrogen atmosphere, bis(4-trifluorovinyloxyphenyl)phenylphosphine oxide of 10.00 g was dissolved with diphenyloxide of 50.00 g, and the mixture was heated at 170°C for 4 hours, and was slowly quenched to room temperature.

[250] GPC (polystyrene column) Mn 2,800 (g/mol).

[251]

[252] (2): Preparation of phosphine oxide type hydrophilic block oligomer (compound

9^3}

[253] A. Preparation of bis { 4-(2-bromotetrafluoroethoxy)-3-chlorosulfonylphenyl } -3-chlorosulfonyl phenylphosphine oxide

[254] A round bottom flask of 1000 mL was put into ice bath, and bis[4-(2-bromo tetrafluoroethoxy)phenyl]phenylphosphine oxide of 66.80 g(0.10 mol) and CHCl of 200 mL were mixed in the flask. Chlorosulfonic acid of 400 g was slowly added thereto dropwise under the nitrogen atmosphere. After 12 hours, the reaction solution was poured into ice water of 2000 mL, and organic formed therein layer was separated and washed with ice water several times, followed by drying. Thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel.

[255]

[256] B. Preparation of bis { 4-(2-bromotetrafluoroethoxy)-3-chlorosulfonylphenyl } -3-fluorosulfonyl phenyl phosphine oxide

[257] Under the nitrogen atmosphere, dried CH CN of 200 mL, bis[4-(2-bromo tetraflu- oroethoxy)-3-chlorosulfonylphenyl]-3-chlorosulfonyl phenyl phosphine oxide of 48.20 g(0.05 mol), and NaF of 21.80 g(0.38 mol) were poured into a round bottom flask of 500 mL, and the mixture was refluxed. After two days, the reactant was filtered with filter paper, and the filtrate was washed with water and dried under vacuum. The dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel. [259] C. Preparation of bis(4-trifluorovinyloxy-3-chlorosulfonylphenyl)-3-fluorosulfonyl phenyl phosphine oxide ( compound 8-3)

[260] Bis[4-(2-bromotetrafluoroethoxy)-3-chlorosulfonylphenyl]-3-fluorosulfonyl phenyl phosphine oxide of 27.40 g(0.03 mol), copper(I) chloride of 5.60 g(0.05 mol), and zinc powder of 5.90 g(0.09 mol) were poured into anhydrous CH CN of 150 mL, and the mixture was agitated and heated for reflux. After 4 days, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. The dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel.

[261]

[262] D. Preparation of hydrophilic block oligomer compound (9-3)

[263] Under the nitrogen atmosphere, bis(4-trifluorovinyloxy-3-chlorosulfonylphenyl)-3-fluorosulfonyl phenyl phosphine oxide of 10.00 g was poured into NMP 50 of mL, and the mixture was heated at 160 °C for 4 hours, and was slowly quenched to room temperature.

[264] GPC (polystyrene column) Mn 3,500 (g/mol).

[265]

[266] 3^*): Preparation of phosphine oxide type multi-block copolymer and electrolyte membrane

[267] The hydrophobic block oligomer (compound 7-3) and the hydrophilic block oligomer (compound 9-3) were mixed in the weight ratios of 5:1, 10:1, and 20:1, and the mixture was poured into NMP (20 wt%). Under the nitrogen atmosphere, the mixture was heated at 200°C for 1 day and slowly quenched to room temperature. The polymer solution obtained therefrom was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-3). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 0.9 (g/dl) )^'\ 0.9 (g/dl) ) , and 1.0 (g/dl) ) , respectively.

[268] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[269] [270] Example 5

[271] The hydrophobic block oligomer (compound 7-1) and the hydrophilic monomer of

4,4'-bis(trifluorovinyloxy)-biphenyl-3,3'-disulfonyl fluoride (compound 8-1) in the Example 1 were mixed in the weight ratios of 5:1, 10:1, and 20:1. The mixture was heated at 250°C for 5 hours and slowly quenched to room temperature. The polymer obtained therefrom was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-4). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5: 1, 10: 1, and 20: 1 was 1.7 (g/dl) )^'\ 1.4 (g/dl) )^'\ and 1.5 (g/dl) )^'\ respectively.

[272] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[273]

[274] Example 6

[275] The hydrophilic block oligomer (compound 9-1) and the hydrophobic monomer of

4,4'-bis(trifluorovinyloxy)biphenyl (compound 6-1) in the Example 1 were mixed in the weight ratios of 5:1, 10:1, and 20:1. The mixture was heated at 250°C for 5 hours and slowly quenched to room temperature. The polymer obtained therefrom was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-5). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 1.2 (g/dl) )- ¹ _J 1.4 (g/dl) )^"', and 1.5 (g/dl) )^"', respectively.

[276] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[277]

[278] Example 7

[279] The hydrophobic block oligomer (compound 7-2) and the hydrophilic monomer of

9,9-bis-(4-trifluorovinyloxyphenyl)fluorene-2,7-disulfonic acid, sodium salt (compound 8-2) in the Example 3 were mixed in the weight ratios of 5: 1, 10: 1, and 20:1, and the mixture was poured into NMP (20 wt%). Under the nitrogen atmosphere, the mixture was heated at 200°C for 1 day and slowly quenched to room temperature. Thus obtained polymer solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-6). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 1.1 (g/dl) )^'\ 1.2 (g/dl) ) , and 1.1 (g/dl) ) , respectively.

[280] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[281]

[282] Example 8

[283] The hydrophilic block oligomer (compound 9-2) and the hydrophobic monomer of

9,9-bis(4-trifluorovinyloxyphenyl)fluorine (compound 6-2) in the Example 3 were mixed in the weight ratios of 5:1, 10:1, and 20:1, and the mixture was poured into NMP (20 wt%). Under the nitrogen atmosphere, the mixture was heated at 200°C for 1 day and slowly quenched to room temperature. Thus obtained polymer solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the acid substituent polymer corresponding to the compound (10-7). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 1.3 (g/dl) )^'\ 1.2 (g/dl) )^'\ and 1.4 (g/dl) )^" \ respectively. [284] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[285]

[286] Example 9

[287] The hydrophobic block oligomer (compound 7-3) and the hydrophilic monomer of

Bis(4-trifluorovinyloxy-3-chlorosulfonylphenyl)-3-fluorosulfonyl phenyl phosphine oxide (compound 8-3) in the Example 4 were mixed in the weight ratios of 5: 1, 10: 1, and 20: 1, and the mixture was poured into NMP (20 wt%). Under the nitrogen atmosphere, the mixture was heated at 200°C for 1 day and slowly quenched to room temperature. Thus obtained polymer solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-8). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 0.9 (g/dl) )- \ 1.2 (g/dl) )^"\ and 1.0 (g/dl) )^"\ respectively.

[288] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[289]

[290] Example 10

[291] The hydrophilic block oligomer (compound 9-3) and the hydrophobic monomer of bis(4-trifluorovinyloxyphenyl)phenylphosphine oxide (compound 6-3) in the Example 4 were mixed in the weight ratios of 5: 1, 10: 1, and 20: 1, and the mixture was poured into NMP (20 wt%). Under the nitrogen atmosphere, the mixture was heated at 200°C for 1 day and slowly quenched to room temperature. Thus obtained polymer solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain an acid substituent polymer corresponding to the compound (10-9). The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated multi-block copolymer. The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio is 5:1, 10:1, and 20:1 was 1.3 (g/dl) )^'\ 1.2 (g/dl) )^'\ and 1.4 (g/dl) )^" \ respectively.

[292] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80°C for 1 day, and dried in a vacuum oven of 140°C for 10 hours to prepare multi-block copolymer electrolyte membrane having a thickness of 50 - 120 D.

[293]

[294] Example 11

[295] I) Preparation of sulfone type of block oligomer (compound 7-4^*)

[296] A. Preparation of 4,4'-sulfonyl-bis(2-bromotetrafluoroethoxy)biphenyl

[297] Anhydrous DMSO of 250 mL and NaH of 7.2 g (0.3 mol) were poured into a round bottom flask of 500 ml under the nitrogen atmosphere, followed by agitation, and 4,4'-sulfonyl diphenol of 25 g (0.1 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 35.8 mL (0.3 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35°C, and the mixture was stirred for 24 hours . The reactant was mixed with water to extract ethylacetate, and thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel.

[298] ^λ H-NMR (CDCl₃, δ in ppm): 7.38 (d), 8.01 (d), ¹⁹F-NMR (CDCl₃, δ in ppm): -68.9

(S), -86.7 (S)

[299]

[300] B. Preparation of 4,4'-sulfonyl-bis(trifluorovinyloxy)biphenyl (compound 6-4)

[301] 4,4'-sulfonyl-bis(2-bromotetrafluoroethoxy)biphenyl of 30 g (49.3 mmol)

[302] , and zinc powder of

[303] 9.7 g (148 mmol)

[304] were added into anhydrous CH CN of 150 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. Thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel to obtain the title compound (the compound of formula 6: R

[305] ^λ H-NMR (CDCl₃, δ in ppm): 7.22 (d), 7.97 (d), ¹⁹F-NMR (CDCl₃, δ in ppm): -

118.3 (dd), -124.9 (dd), -135.7 (dd). [307] C. Preparation of sulfone type of block oligomer (Compound 7-4)

[308] Under the nitrogen atmosphere, 4,4'-sulfonyl-bis(trifluorovinyloxy)biphenyl was heated at 170°C for 4 hours, and was slowly quenched to room temperature to obtain the

title compound (the compound of formula: R =

° , B= C₄F₆, and P = -O-)

GPC (polystyrene column) Mn 2,500 (g/mol).

[309] 2) Preparation of fluorene type of block oligomer (compound 12-4)

[310] A. Preparation of 9,9-bis- { 4-(2-bromotetrafluoroethoxy)-phenyl } fluorene

[311] Anhydrous DMSO of 1000 mL and NaH of 10.56 g (0.44 mol) were poured into a round bottom flask of 2000 ml under the nitrogen atmosphere, followed by agitation, and 9,9-bis(4'-hydroxyphenyl)fluorene of 70.10 g (0.20 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 114.40 g (0.44 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35 °C , and the mixture was stirred for 24 hours . The reactant was mixed with water to extract di- ethylether, and thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel to obtain the title compound. [312] ^λ H-NMR (CDCl₃, δ in ppm): 7.06-7.80 (various m, CH arom.), ¹⁹F-NMR (CDCl₃, δ in ppm): -68.6 (s), -86.5 (s). [313]

[314] B. Preparation of 9,9-bis(4-trifluorovinyloxyphenyl)fluorine (compound 11-4)

[315] 9,9-bis-[4-(2-bromotetrafluoroethoxy)-phenyl]fluorene of 70.80 g (0.10 mol) and zinc powder of 19.60 g (0.30 mol) were added into anhydrous diethylenegly- coldimethylether (diglyme) of 500 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. Thus dried product was separated and purified by normal hexane through a column including silica gel to obtain

the title compound (the compound of formula 11 : R' = , and P - -O-)

[316] ^λ H-NMR (CDCl₃, δ in ppm): 6.93-7.78 (various m, CH arom.), ¹⁹F-NMR (CDCl₃, δ in ppm): -119.9 (dd), -126.8 (dd), -134.2 (dd). [317] [318] C. Preparation of fluorene type of block oligomer (compound 12-4)

[319] Under the nitrogen atmosphere, 9,9-bis(4-trifluorovinyloxyphenyl)fluorene of

10.00 g was dissolved with phenylether 10.00 g, and the mixture was heated at 170 °C for 7 hours, and slowly quenched to room temperature to obtain the title compound (the compound of

formula 9: R¹ =

, B= C₄F₆, and P = -O-). GPC (polystyrene column) Mn 3,100 (g/mol).

[320]

[321] 3^*) Preparation of sulfonated multi-block copolymer (compound 5-4^*) and membrane

[322] Under the nitrogen atmosphere, the sulfone type of block oligomer (compound 7-4) and the fluorene type of block oligomer (compound 12-4) were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was dissolved with diphenylether (50wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to

obtain the block copolymer (the compound of formula 3: R =

[323] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to fluorene repeated unit was slowly added dropwise into the polymer solution to sulfonate the polymer for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5:

R =

-O-). [324] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-4 and compound 12-4 is 1:1, 5:1, and 10:1 was 1.1 (g/dl)^"1, 1.2 (g/dl)^"1, and 0.9 (g/dl)^"1, respectively.

[325] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[326]

[327] Example 12

[328] I) Preparation of benzophenone type of block oligomer (compound 7-5^*)

[329] A. Preparation of 4,4'-bis(2-bromotetrafluoroethoxy)benzophenone

[330] Anhydrous DMSO of 250 mL and NaH of 7.2 g (0.3 mol) were poured into a round bottom flask of 500 ml under the nitrogen atmosphere, followed by agitation, and 4,4'-dihydroxybenzophenone of 21.4 g (0.1 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 35.8 mL (0.3 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35 °C , and the mixture was stirred for 24 hours . The reactant was mixed with water to extract ethylacetate. Thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel to obtain the title compound.

[331] ^λ H-NMR (CDCl₃, δ in ppm): 7.18 (d), 7.86 (d), ¹⁹F-NMR (CDCl₃, δ in ppm): -68.7

(S), -86.5 (S).

[332]

[333] B. Preparation of 4,4'-bis(trifluorovinyloxy)benzophenone (compound 6-5)

[334] 4,4'-bis(2-bromotetrafluoroethoxy)benzophenone of 28.2 g (49.3 mmol)

[335] and zinc powder of

[336] 9.7 g (148 mmol)

[337] were added into anhydrous CH CN of 150 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. Thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel to obtain the

[338] title compound (the compound of formula 6: R

, and P = -O-). [339] ^λ H-NMR (CDCl₃, δ in ppm): 7.22 (d), 7.97 (d), ¹⁹F-NMR (CDCl₃, δ in ppm): -

117.5 (dd), -123.8 (dd), -136.5 (dd). [340]

[341] C. Preparation of benzophenone type of block oligomer (compound 7-5)

[342] Under the nitrogen atmosphere, 4,4'-bis(trifluorovinyloxy)benzophenone was heated at 170 °C for 4 hours, and was slowly quenched to room temperature to obtain the title

compound (the compound of formula 7: R

= , B- C4F6, and P - -O-)

GPC (polystyrene column) Mn 2,800 (g/mol).

[343] 1) Preparation of biphenyl type block oligomer (compound 12-5)

[344] A. Preparation of 4,4'-bis(2-bromotetrafluoroethoxy)biphenyl

[345] Anhydrous DMSO of 700 mL and NaH of 10.56 g (0.44 mol) were poured into a round bottom flask of 2000 ml under the nitrogen atmosphere, followed by agitation, and 4,4'-biphenol of 37.20 g (0.20 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 114.40 g (0.44 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35 °C , and the mixture was stirred for 24 hours . The reactant was mixed with water to extract diethylether, and thus dried product was separated and purified by normal hexane through a column including silica gel to obtain the title compound. [346] ^λ H-NMR (CDCl₃, δ in ppm): 7.31 (d), 7.58 (d), ¹⁹F-NMR (CDCl₃, δ in ppm): -68.5

(S), -86.4 (S). [347]

[348] B. Preparation of 4,4'-bis(trifluorovinyloxy)biphenyl (compound 11-5)

[349] 4,4'-bis(2-bromotetrafluoroethoxy)biphenyl of 54.40 g (0.10 mol) and zinc powder of 19.60 g (0.30 mol) were added into anhydrous CH CN of 300 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. Thus dried product was separated and purified by normal hexane through a column including

silica gel to obtain the title compound (the compound of formula 8: R¹ = and P = -O-)

[350] ^λ H-NMR (CDCl₃, δ in ppm): 7.18 (d), 7.54 (d), ¹⁹F-NMR (CDCl₃, δ in ppm): -

119.9 (dd), -126.7 (dd), -134.9 (dd). [351]

[352] C. Preparation of biphenyl type of block oligomer (compound 12-5)

[353] Under the nitrogen atmosphere, 4,4'-bis(trifluorovinyloxy)biphenyl was heated at

170 °C for 4 hours, and was slowly quenched to room temperature to obtain the title

compound (the compound of formula 9: R' = , B- CΛ, and P - -O-)

GPC (polystyrene column) Mn 3,000 (g/mol).

[354]

[355] 3) Preparation of sulfonated multi-block copolymer preparation (formula 5-5) and membrane

[356] Under the nitrogen atmosphere, the benzophenone type of block oligomer

(compound 7-5) having low sulfonization activity and the biphenyl type of block oligomer (compound 12-5) having high sulfonization activity were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block copolymer (the compound of formula 3: R =

[357] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to biphenyl repeated unit was slowly added dropwise into the polymer solution to sulfonate the polymer for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer.

[358] The above acid substituent polymer was poured into a mixed solution of K CO aqueous solution (10 wt%) and DMSO for hydrolysis for 1 day. Thus obtained product was treated with cone. HCl aqueous solution and distilled water to prepare sulfonated

multi-block copolymer (the compound of formula 5: R = ^"^ ^~ " , R" =

( 1 -S+y ;2), and P = -O-).

[359] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-5 and compound 12-5 is 1:1, 5:1, and 10:1 was 1.0 (g/dl)^"1, 0.8 (g/dl)^"1, and 0.9 (g/dl)^"1, respectively.

[360] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D. [361]

[362] Example 13

[363] 1) Preparation of fluorophenyl type of block oligomer (compound 7-6)

[364] A. Preparation of l,4-bis(2-bromotetrafluoroethoxy)tetrafluorobenzene

[365] Anhydrous DMSO of 250 mL and NaH of 7.2 g (0.3 mol) were poured into a round bottom flask of 500 ml under the nitrogen atmosphere, followed by agitation, and tetrafluorohydroquinone of 18.2 g (0.1 mol) was slowly added thereto 4 times. After the generation of hydrogen gas is completed, 1,2-dibromotetrafluoroethane of 35.8 mL (0.3 mol) was slowly added thereto dropwise to prevent the reaction temperature from exceeding over 35 °C , and the mixture was stirred for 24 hours . The reactant was mixed with water to extract ethylacetate, and thus dried product was separated and purified by normal hexane through a column including silica gel to obtain the title compound. [366]

[367] B. Preparation of l,4-bis(trifluorovinyloxy)tetrafluorobenzene (compound 6-6)

[368] l,4-bis(2-bromotetrafluoroethoxy)tetrafluorobenzene of 26.6 g (49.3 mmol) and zinc powder of 9.7 g (148 mmol) were added into anhydrous CH CN of 150 mL under the nitrogen atmosphere, and the mixture was agitated and heated for reflux. After 16 hours, the reactant was filtered with filter paper, and the filtrate was dried under vacuum. Thus dried product was separated and purified by normal hexane and ethylacetate through a column including silica gel to obtain the title compound (the compound of formula 6: R

[369]

[370] C. Preparation of fluorophenyl type of block oligomer (compound 7-6)

[371] Under the nitrogen atmosphere, l,4-bis(trifluorovinyloxy)tetrafluorobenzene was heated at 170 °C for 5 hours, and was slowly quenched to room temperature to obtain the title compound (the compound of formula 7: R =

^{F F} , B= C4F6, and P = -O-) GPC (polystyrene column) Mn 4,000 (g/mol).

[372] [373] 2) Preparation of the sulfonated multi-block copolymer (compound 5-6) and membrane

[374] Under the nitrogen atmosphere, the fluorophenyl type of block oligomer (compound 7-6) having low sulfonization activity and the fluorene type of block oligomer (compound 12-4) having high sulfonization activity in the Example 11 were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was dissolved with diphenylether (50wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered,

and dried to obtain the block copolymer (the compound of formula 3: R =

R' —

[375] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to fluorene repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

, R" = (l ϊ£+y≤2), and P = -O-)-

[376] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-6 and compound 12-4 is 1:1, 5:1, and 10:1 was 1.3 (g/dl)^"1, 1.7 (g/dl)^"1, and 1.8 (g/dl)^"1, respectively. [378] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[379]

[380] Example 14

[381] Under the nitrogen atmosphere, the sulfone type of block oligomer (compound 7-4) and the fluorene type of monomer of 9,9-bis(4-trifluorovinyloxyphenyl)fluorine (compound 11-4) in the Example 11 were mixed in the weight ratios of 1 : 1, 5: 1, and 10:1, and the mixture was dissolved with diphenylether (50wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block

copolymer (the compound of formula 3: R =

, R' - and P = -O-).

[382] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to fluorene repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

(l ≤L+y≤.), and P = -O-).

[383] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-4 and compound 11-4 is 1:1, 5:1, and 10:1 was 1.3 (g/dl)^"1, 1.5 (g/dl)^"1, and 1.5 (g/dl)^"1, respectively.

[384] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte me mbrane having a thickness of 50 ~ 120 D.

[385]

[386] Example 15

[387] Under the nitrogen atmosphere, the fluorene type of block oligomer (compound

12-4) and the sulfone type of monomer of 4,4'-sulfonyl-bis(trifluorovinyloxy)biphenyl (compound 6-4) in the Example 11 were mixed in the weight ratio of 1 : 1, 5: 1, and 10:1, and the mixture was dissolved with diphenylether (50wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block

copolymer (the compound of formula 3: R =

» R^{1 ~} and P = -O-).

[388] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to fluorene repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

, R" = (l .S+y-2), and P = -O-).

[389] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-4 and compound 11-4 is 1:1, 5:1, and 10:1 was 1.3 (g/dl)^"1, 1.4 (g/dl)^"1, and 1.5 (g/dl)^"1, respectively.

[390] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D. [392] Example 16

[393] Under the nitrogen atmosphere, the benzophenone type of block oligomer

(compound 7-5) and the biphenyl type of monomer of

4,4'-bis(trifluorovinyloxy)biphenyl (compound 11-5) in the Example 12 were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was dissolved with diphenylether (50wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with tetrahydrofuran, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block

copolymer (the compound of formula 3: R = *— ' ^-^ , R¹ = and P = -O-).

[394] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 5 mol times to biphenyl repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

[395] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-5 and compound 11-5 is 1:1, 5:1, and 10:1 was 1.1 (g/dl)^"1, 1.1 (g/dl)^"1, and 1.2 (g/dl)^"1, respectively.

[396] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[397]

[398] Example 17

[399] Under the nitrogen atmosphere, the biphenyl type of block oligomer (compound

12-5) and the benzophenone type of monomer of

4,4'-bis(trifluorovinyloxy)benzophenone (compound 6-5) in the Example 12 were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was dissolved with NMP (20wt%). The mixture was heated for 16 hours for reflux and slowly quenched to room temperature under the nitrogen atmosphere. Thus obtained polymer solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block copolymer (the compound of

formula 3: R = ^W ^ , R' = , and P = -O-).

[400] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to biphenyl repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

p = .Q-).

[401] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 12-5 and compound 6-5 is 1:1, 5:1, and 10:1 was 0.7 (g/dl)^"1, 0.8 (g/dl)^"1, and 0.8 (g/dl)^"1, respectively.

[402] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[403]

[404] Example 18

[405] Under the nitrogen atmosphere, the fluorophenyl type of block oligomer (compound

7-6) in the Example 13 and the fluorene type of monomer of

9,9-bis(4-trifluorovinyloxyphenyl)fluorine (compound 11-4) in the Example 11 were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was dissolved with diphenylether (40wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block copolymer (the compound of formula 3: R -

^F , R' -

[406] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 5 mol times to biphenyl repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

, R" = (1 ≤L+y i2), and P = -O-).

[407] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 7-5 and compound 11-5 is 1:1, 5:1, and 10:1 was 1.0 (g/dl)^"1, 1.5 (g/dl)^"1, and 1.3 (g/dl)^" \ respectively.

[408] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on a glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[409]

[410] Example 19

[411] Under the nitrogen atmosphere, the fluorene type of block oligomer (compound

12-4) in the Example 11 and the fluorophenyl type of monomer of l,4-bis(trifluorovinyloxy)tetrafluorobenzene (compound 6-6) in the Example 13 were mixed in the weight ratios of 1:1, 5:1, and 10:1, and the mixture was dissolved with diphenylether (50wt%). The mixture was heated at 250°C for 16 hours and slowly quenched to room temperature. Thus obtained polymer was dissolved with DMAc, and the solution was slowly added dropwise into excess methanol to precipitate. The precipitant was filtered, and dried to obtain the block copolymer (the compound of formula 3: R =

, R' =

[412] Under the nitrogen atmosphere, the above block copolymer was dissolved with dichloroethane (lwt%), and chloro sulfonic acid of 4 mol times to fluorene repeated unit was slowly added dropwise into the polymer solution to sulfonate for 7 hours. The solvent was removed from the mixture, and the product was washed with distilled water several times to obtain the sulfonated block copolymer (the compound of formula 5: R =

, R" = (1 <k+y .2), and P = -O-).

[413] The intrinsic viscosity (Cannon-Fenske viscometer) of the copolymer was evaluated. The viscosity of the polymer wherein the weight ratio of compound 12-4 and compound 6-6 is 1:1, 5:1, and 10:1 was 1.1 (g/dl)-l, 1.6 (g/dl)-l, and 1.7 (g/dl)-l, respectively.

[414] The above obtained polymer was dissolved with DMAc (15 wt%), and was cast on the glass plate. The thickness of the copolymer solution was controlled by film applicator, and the solution was dried at 80 °C for 1 day, and dried in a vacuum oven of 140 °C for 10 hours to prepare the sulfonated multi-block copolymer electrolyte membrane having a thickness of 50 ~ 120 D.

[415]

[416] Experimental Example 1 : Evaluation of Proton Conductivity

[417] The proton conductivity was measured for each of the multi-block copolymer electrolyte membrane prepared in the Examples 1, 3 and 4 wherein the weight ratio of hydrophobic block oligomer and hydrophilic block oligomer is 10:1, and the multi- block copolymer electrolyte membrane prepared in the Examples 11 - 13 wherein the weight ratio of the low sulfonization activity block oligomer and the high sulfonization activity block oligomer is 5:1 by the potentio-static two-probe method. First, carbon paper electrodes with a size of 1x1 cm and 1.5x1.5 cm were attached to both sides of a specimen with the size of 2x2 cm². Next, an AC voltage of 5 mV was applied to both ends of the electrode at a frequency of 1 MHz to 100 MHz, while ultra-pure water was allowed to flow outside the above structure. Here, impedance could be obtained through the AC current applied to the both ends of the electrode, and by using the impedance, the proton conductivity of each multi-block copolymer electrolyte membrane could be obtained.

[418] FlG. 1 shows proton conductivity measure results of the electrolyte membranes of the Examples 1, 3, and 4 and Nafion 115 . Also, FIG. 2 shows proton conductivity measure results of the electrolyte membranes of the Examples 11 to 13 and Nafion 115 . As shown in FIGS. 1 and 2, the multiblock copolymer electrolyte membranes of the Examples 1, 3, 4 and 11 to 13 according to the present invention show improved proton conductivity compared to the Nafion that is conventionally used as a polymer electrolyte membrane.

[419]

[420] Experimental Example 2: Evaluation of Polymer Electrolyte Fuel Cell TPEMFO

[421] To evaluate the polymer electrolyte fuel cell capacity, the multi-block copolymer electrolyte membrane prepared in the Example 4 wherein the weight ratio of hydrophobic block oligomer and hydrophilic block oligomer is 10:1, and the multi-block copolymer electrolyte membrane prepared in the Example 11 wherein the weight ratio of low sulfonization activity block oligomer and high sulfonization activity block oligomer is 5:1 each were prepared in the thickness of 100 μm. At this time, 5 layered MEA (membrane electrode assembly) was prepared, and 0.5 mg Pt/cm² was loaded on both anode and cathode. The electrode size was 5x5 cm , and the electrolyte membrane size was 10x10 cm². To prepare catalyst slurry which is evenly dispersed without aggregation, IPA (isopropyl alcohol), post-sulfonated multi-block copolymer solution corresponding to the above electrolyte membrane, and water were mixed in proper amounts (10 weight % of catalyst ink solvent), to prepare a well-dispersed mixed solvent. The solvent was mixed with a catalyst, followed by stirring. Ultrasonication was performed to the mixture for 5 minutes, followed by pulverizing the catalyst cluster by ball milling to make the particles smaller.

[422] The high-temperature press conditions for the above electrolyte membrane and

GDE (gas diffusion electrode) were as follows; the temperature of a high temperature presser was raised to 140 °C , which was maintained at 0.1 ton for 5 minutes to make sure that the heat was transmitted enough. Then, it stood at 1.0 ton for 2 minutes so that the electrolyte membrane and GDE were adhered tightly.

[423] Thus resulted MEA was assembled in a single cell, and the capacity of the polymer electrolyte fuel cell was measured under the following conditions; the unit cell temperature was 70 °C , the flow rates of hydrogen and air was 300 sc cm and 1200 sc cm, respectively, the temperatures of bubbler lines of anode and cathode were set at 80 °C and 85 °C , respectively, and the humidity was 100%. OCV (open circuit voltage) was over 1.0 V, and the pulse was given at constant voltage mode. As a result, the electrolyte membrane produced in the Examples 4 and 11 has the capacities of 0.8 A/ cm² and 0.9 A/cm², respectively, at 0.6V.

[424]

[425] Experimental Example 3: Evaluation of Direct Methanol Fuel Cell TDMFO

[426] The electrolyte membrane having the thickness of 100 μm prepared in the

Examples 4 and 11 was used for the evaluation of capacity of direct methanol fuel cell. Pt-Ru black was used as fuel electrode (anode) catalyst, and Pt black was used as air electrode (cathode) catalyst. To prepare catalyst slurry which was well dispersed without aggregation, IPA, post-sulfonated multi-block copolymer solution corresponding to the above electrolyte membrane, and water were mixed in proper amounts (10 weight % of catalyst ink solvent), to prepare a well-dispersed mixed solvent. The solvent was mixed with a catalyst, followed by stirring. Ultrasonication was performed to the mixture for 5 minutes, followed by pulverizing the catalyst cluster by ball milling to make the particles smaller.

[427]

[428] The above electrolyte membranes were inserted into a clamping device, and was heated behind in a thermal dryer (80° C) for 20 minutes to eliminate moisture completely. Thus resulted catalyst ink of 0.1-20 cc/cm was taken and sprayed on the front side of a grid by using a spray gun, to prepare 30 μm or less of active layer (2 mg/cm ). This time, the carrier gas pressure was 0.01-2 atmospheric pressure. The catalyst slurry solvent was continuously evaporated while a thermal drier was heating and spray-coating the above electrolyte membrane behind the grid. [429] This prepared electrodes were high-pressed, putting the above electrolyte membrane including active layer in between, at 140 °C under the pressure of 5-100 kg/ cm², for 3-10 minutes, to prepare the final MEA. At this time, the electrolyte membrane was a little bigger than the electrode. The electrode's size was 3x3 cm , and the electrolyte membrane's size was 6x6 cm . Thus produced electrode-electrolyte membrane assembly (MEA) was measured under the following conditions: [430] Operating Temperature: 80 °C ;

[431] Amount of Catalyst: 2 mg/cm ;

[432] Fuel: 2 M methanol; and

[433] Oxygen flowrate: 1000 sc cm.

[434]

[435] As a result, the electrolyte membrane produced in the Examples 4 and 11 has the capacities of 0.64 A/cm and 0.62 A/cm at 0.4V, respectively. [436] [437] Those skilled in the art will appreciate that the concepts and specific embodiments disclosed in the foregoing description can be readily utilized as a basis for modifying or designing other embodiments. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the spirit and scope of the present invention as set forth in the appended claims.

[438]

[439] INDUSTRIAL APPLICABILITY

[440] T he electrolyte membrane using the multi-block copolymer comprising perfluoro- cyclobutane ring according to the present invention has high proton conductivity, good mechanical property, and chemical stability, and can easily control the distribution, position, and number of sulfonic acid group in the polymer backbone, and the membrane properties are not decreased even though sulfonic acid group is increased.

Claims

[1] 1. A block copolymer comprising a repeated unit represented by the following formula (1) and a repeated unit represented by the following formula (4): [2] (-R-P-Q-P-) (1)

(-R"-P-Q-P-) (4) wherein,

-P- is each independently selected from the group consisting of -O-, -S-, -SO-,

SO -, -CO-, -NH-, -NR -, and -R -, wherein R is alkyl or aryl of 1 ~ 25 carbon atoms, and R is alkylene or arylene of 1 ~ 25 carbon atoms,

-Q- is each independently l,2-perfluorocyclobutylene(C F ),

R is aromatic group which is unsubstituted or substituted with one or more inert groups which do not induce other chemical reaction in forming the group -Q-,

R" is aromatic group which has one or more benzene rings substituted with one or more -PO 3 H 2 or -SO 3 H.

[3] 2. The block copolymer according to claim 1, wherein the benzene rings are linked directly or by -O-, -S-, -(CH₂)-, -(C(O))-, -(S(O)₂)-, -(-P(O))-, -(Si(CHp₂)-, -(C(CH ) )-, -(C(CF ) )- or -(Si(C H ) )- when R or R" has two or more benzene

3 2 3 2 6 5 2 rings.

[4] 3. The block copolymer according to claim 1, wherein R represents one or more aromatic compounds selected from the following group: [5]

;and

R" represents aromatic compound which is substituted with one or more -PO H

3 2 or -SO H on benzene ring of one or more compound R' selected from the following group:

wherein A is -NO 2 or -CF 3.

[7] 4. The block copolymer according to claim 3, wherein R represents one or more aromatic compounds selected from the following group:

;and

R" represents aromatic compound which is substituted with one or more -PO H

[9]

[10] 5. The block copolymer according to claim 1, wherein the block copolymer comprises a repeated unit represented by the following formula (5):

wherein R and R" are each as defined in claim 1, and n and m each are independently an integer of 1 to 10,000.

[12] 6. The block copolymer according to claim 3, wherein R is one or more aromatic compounds having low sulfonization activity selected from the following group: [13]

,and

R" is aromatic compound which is substituted with one or more -SO H on benzene ring of one or more compound R' having high sulfonization activity selected from the following group:

[14]

[15] 7. The block copolymer according to claim 6, wherein R represents aromatic compound selected from the following group:

,and

R" represents aromatic compound which is substituted with one or more -SO H on benzene ring of one or more compound R' selected from the following group:

[18] 8. The block copolymer according to claim 1, wherein the weight average molecular weight of the block comprising the repeated unit represented by the formula (1) is 500 to 500,000 (g/mol), and the weight average molecular weight of the block comprising the repeated unit represented by the formula (4) is 500 to 500,000.

[19] 9. A process for preparing the block copolymer according to claim 1, comprising a) a step of polymerizing aromatic monomer represented by the following formula (6):

[20]

F₂C=FC-P-R-P-CF=CF₂ (6), [21] wherein P and R are each as defined in claim 1, which has perfluorovinyloxy group at both ends, to produce a hydrophobic block oligomer represented by the following formula

(7):

[²²I F₂C=FC-P-C-R-P-Q-P-^-R-P-CF=CF₂ (7), herein P, Q and R are each as defined in claim 1, and n' is an integer of 1 to 10,000; b) a step of polymerizing aromatic monomer represented by the following formula (8): t²³] F₂C=FC-P- R"'-P-CF=CF₂ (8) wherein P is as defined in claim 1, and R'" is aromatic group having one or more benzene rings which are substituted with one or more acid substituent groups selected from the group consisting of -SO Cl, -SO F, -SO -M⁺, -P(O)(OA) , -PO H-M⁺ and -PO -2M⁺, wherein A is alkyl of 1 ~ 4 carbon atoms, and M is alkali metal, which has acid substituent group and perfluorovinyloxy group at both ends, to produce a hydrophilic block oligomer represented by the following formula (9): [24] F₂C=FC-P-(-R-P-Q-P-)m- R'"-P-CF=CF₂ (9), wherein P and Q are each as defined in claim 1, R'" is as defined above, and m' is an integer of 1 to 10,000; c) a step of reacting the hydrophobic block oligomer prepared in the step a) and the hydrophilic block oligomer prepared in the step b) to produce an acid substituent block copolymer represented by the following formula (10):

[²⁵I -(-R-P-Q-P-)_n-(-R'"-P-Q-P-)_m- (¹⁰) wherein P, Q and R are each as defined in claim 1, R'" is as defined above, and n and m each are an integer of 1 to 10,000; and d) a step of converting the acid substituent group (R'") of the acid substituent block copolymer prepared in the step c) into acid group (R") wherein R" is as defined in claim 1.

[26] 10. A process for preparing the block copolymer according to claim 1, comprising a) a step of polymerizing aromatic monomer represented by the following formula (6):

[27]

F₂C=FC-P-R-P-CF=CF₂ (6), [28] wherein P and R are each as defined in claim 1, which has perfluorovinyloxy group at both ends, to produce a hydrophobic block oligomer represented by the following formula

(7):

[²^ F₂C=FC-P-C-R-P-Q-P-^-R-P-CF=CF₂ (7),

[30] wherein P, Q and R are each as defined in claim 1 and n' is an integer of 1 to

10,000; b) a step of polymerizing aromatic monomer represented by the following formula (8):

[31] F₂C=FC-P- R"'-P-CF=CF₂ (8)

[32] wherein P is as defined in claim 1, and R'" is as defined in claim 9, which has acid substituent group and perfluorovinyloxy group at both ends, with the hydrophobic block oligomer prepared in the step a) to produce an acid substituent block copolymer represented by the following formula (10):. t³³] -(.R.p.Q-P-)_I1-(-R--P-Q-P-)_m- (10), wherein P, Q and R are each as defined in claim 1, R'" is as defined above, and n and m each are an integer of 1 to 10,000; and c) a step of converting the acid substituent group (R'") of the acid substituent block copolymer prepared in the step b) into acid group (R") wherein R" is as defined in claim 9.

[34] 11. A process for preparing the block copolymer according to claim 1, comprising a) a step of polymerizing aromatic monomer represented by the following formula (8):

[35] F₂C=FC-P- R'"-P-CF=CF₂ (8), wherein P is as defined in claim 1, and R'" is as defined in claim 9, which has acid substituent group and perfluorovinyloxy group at both ends, to produce a hydrophilic block oligomer represented by the following formula (9): [36] F₂C=FC-P-(-R-P-Q-P-)_m- R'"-P-CF=CF₂ (9),

[37] wherein P and Q are each as defined in claim 1, R'" is as defined above, and m' is an integer of 1 to 10,000; b) a step of polymerizing aromatic monomer represented by the following formula (6):

[38]

F₂C=FC-P-R-P-CF=CF₂ (6), [39] wherein P and R are each as defined in claim 1, which has perfluorovinyloxy group at both ends, with the hydrophilic block oligomer prepared in the step a) to produce an acid substituent block copolymer represented by the following formula (10):.

[⁴⁰I -(-R-P-Q-P-)_n-(-R'"-P-Q-P-)_m- ⁽¹⁰⁾ wherein P, Q and R are each as defined in claim 1, R'" is as defined above, and n and m each are an integer of 1 to 10,000; and c) a step of converting the acid substituent group (R'") of the acid substituent block copolymer prepared in the step b) into acid group (R") wherein R" is as defined in claim 1.

[41] 12. The process for preparing the block copolymer according to any one of claims 9 to 11, wherein the acid substituent group (R'") is converted into acid group (R") by adding acid solution to the acid substituent block copolymer when R'" comprises the acid substituent group of -SO -M⁺, -PO H-M⁺ or -PO ^2M⁺; or the acid substituent group (R'") is converted into acid group (R") by adding the acid substituent block copolymer to acid or base solution for hydrolysis, and then treating the acid substituent block copolymer with acid solution when R'" comprises the acid substituent group of -SO Cl, -SO F or -P(O)(OA) . [42] 13. A block copolymer comprising a repeated unit represented by the following formula (1) and a repeated unit represented by the following formula (2):

[⁴³I (-R-P-Q-P-) (1)

(-R'-P-Q-P-) (2) wherein,

-P- is each independently selected from the group consisting of -O-, -S-, -SO-,

SO -, -CO-, -NH-, -NR -, and -R -, wherein R is alkyl or aryl of 1 ~ 25 carbon atoms, and R2 is alkylene or arylene of 1 ~ 25 carbon atoms,

-Q- is each independently l,2-perfluorocyclobutylene(C F ),

4 6

R is one or more aromatic compounds having low sulfonization activity selected from the following group: [44]

,and

R' is one or more aromatic compounds having high sulfonization activity selected from the following group:

wherein A is -NO 2 or -CF 3.

[46] 14. The block copolymer according to claim 13, wherein the block copolymer comprises a repeated unit represented by the following formula (3):

wherein, R and R' are each as defined in claim 13, and n and m each are independently an integer of 1 to 10,000.

[48] 15. A process for preparing the block copolymer according to claim 13, comprising a) a step of polymerizing aromatic monomer represented by the following formula (6): [49]

F₂C=FC-P-R-P-CF=CF₂ (6),

[50] wherein P and R are each as defined in claim 13, which has low sulfonization activity and perfluorovinyloxy group at both ends, to produce a block oligomer having low sulfonization activity represented by the following formula (7):

[⁵¹I F₂C=FC-P-C-R-P-Q-P-^-R-P-CF=CF₂ (7), wherein P, Q and R are each as defined in claim 13, and n' is an integer of 1 to 10,000; b) a step of polymerizing aromatic monomer represented by the following formula (11): t⁵²] F₂C=FC-P-R'-P-CF=CF₂ (11)

[53] wherein P and R' are each as defined in claim 13, which has high sulfonization activity and perfluorovinyloxy group at both ends, to produce a block oligomer having high sulfonization activity represented by the following formula (12):

^[54] F₂C=FC-P-(-R'-P-Q-P-)_m-R'-P-CF=CF₂ (12), wherein P, Q and R' are each as defined in claim 13, and m' is an integer of 1 to 10,000; and c) a step of polymerizing the block copolymer prepared in the step a) having low sulfonization activity and the block copolymer prepared in the step b) having high sulfonization activity.

[55] 16. A process for preparing the block copolymer according to claim 13, comprising a) a step of polymerizing aromatic monomer represented by the following formula (6):

[56]

F₂C=FC-P-R-P-CF=CF₂ (6),

[57] wherein P and R are each as defined in claim 13, which has low sulfonization activity and perfluorovinyloxy group at both ends, to produce a block oligomer having low sulfonization activity represented by the following formula (7): t⁵⁸^ F₂C=FC-P-(-R-P-Q-P-)_n-R-P-CF=CF₂ (7),

[59] wherein P, Q and R are each as defined in claim 13, and n' is an integer of 1 to

10,000; and b) a step of polymerizing the block copolymer having low sulfonization activity prepared in the step a) and aromatic monomer represented by the following formula (11):

[60] F₂C=FC-P-R'-P-CF=CF₂ (11), wherein P and R' are each as defined in claim 13, which has high sulfonization activity and perfluorovinyloxy group at both ends.

[61] 17. A process for preparing the block copolymer according to claim 1, comprising a) a step of polymerizing aromatic monomer represented by the following formula (11):

[62] F₂OFC-P-R'-P-CF=CF₂ (11),

[63] wherein P and R' are each as defined in claim 13, which has high sulfonization activity and perfluorovinyloxy group at both ends, to produce a block oligomer having high sulfonization activity represented by the following formula (12):

^[64] F₂C=FC-P-(-R'-P-Q-P-)_m-R'-P-CF=CF₂ (12),

[65] wherein P, Q and R' are each as defined in claim 13, and m' is an integer of 2 to

10,000; and b) a step of polymerizing the block copolymer having high sulfonization activity prepared in the step a) and aromatic monomer represented by the following formula (6):

[66]

F₂C=FC-P-R-P-CF=CF₂ (6), wherein P and R are each as defined in claim 13, which has low sulfonization activity and perfluorovinyloxy group at both ends. [67] 18. A process for preparing the block copolymer according to claim 6, comprising a step of sulfonating the block copolymer prepared by any one of claims 15 to 17. [68] 19. The process according to claim 12, wherein the block copolymer is sulfonated by using a sulfonating agent selected from the group consisting of chlorosulfonic acid, sulfur trioxide, sulfuric acid, fuming sulfuric acid, and acyl sulfate. [69] 20. An electrolyte membrane comprising the block copolymer according to any one of claims 1 to 8. [70] 21. The electrolyte membrane according to claim 20, wherein the electrolyte membrane is flat sheet membrane, hollow fiber membrane, composite membrane, or tube membrane. [71] 22. A process for preparing electrolyte membrane, comprising a step of melting an acid substituent block copolymer represented by the following formula (10) or dissolving an acid substituent block copolymer represented by the following formula (10) with organic solvent:

[⁷²J -(.R.p.Q-P-)_I1-(-R--p.Q.p-)_m- (10),

[73] wherein P, Q, R, R'", n and m are each as defined in claim 9, to prepare polymeric membrane; and a step of converting the acid substituent group (R'") into acid group (R") wherein

R" is as defined in claim 9. [74] 23. A process for preparing electrolyte membrane, comprising a) a step of dissolving the block copolymer according to claim 1 or 6 with organic solvent; b) a step of coating the polymer solution on a substrate to form a film; and c) a step of drying the formed film.

[75] 24. The process for preparing electrolyte membrane according to claim 23, wherein the substrate is solid substrate comprising glass plate, metal or ceramic; or porous polymer substrate comprising polysulfone or polyetheramide.

[76] 25. A fuel cell comprising the electrolyte membrane according to claim 20.

[77] 26. The fuel cell according to claim 25, wherein the fuel cell is polymer electrolyte membrane fuel cell or direct methanol fuel cell.