CA2131988A1 - Norbornene polymerization initiators and polymers prepared therewith - Google Patents

Abstract

The present invention relates to a novel compound, its use as an initiator in anionic polymerizations yielding norbornene-terminated homopolymers of block copolymers, and the further use of said norbornene-terminated polymers as macromonomers in the preparation of graft copolymers.

Description

W~ 93/20120 2 1 3 1 9 8 8 PCI`/US93/01472 ., ~

NORBO~NENE ~oI~n~ERIzA~IoN ~NITIATOR8 aND POLW~R8 PREPAE~ED TBERE~IIT~
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
S The present invention relates to a novèl compound, its use as an initiator in anionic polymerizations yielding norbornene-terminated homopolymers of block copolymers, and the further use of said norbornene-terminated polymers as macromonomers in the preparation of graft ;~ copolymers.
DESCRIPrION OF RELATED ART
Anionic polymerization proceeds ~y attack on a vinyl monomer of a basic tnucleophilic) species resulting in~the heterolytic splitting of the double ~ , ~ bond to produce a carbon anion followed by ~, : propagation of this ion. The most common initiators used in such polymerization reactions are the alkyl and aryl derivatives of alkali metals, particularly ;lithium alkyls. Organolithium initiators are particularIy preferred since they are readily prepared by reaction of the lithium metal with alkyl or aryl halides and are soluble in the hydrocarbon solvents used in their preparation as well as solvents used in solution polymerization reactions.
N-butyl lithium and sec-butyl lithium are generally preferred initiators used for the anionic polymerization~of vinyl and diolefin monomers . , ~ . , ~ .
including vinyl aromatic monomers, acrylic and methacrylic monomers and diolefin monomers such as butadiene or isoprene. A representative detail of organo-lithium initiators and their method of preparation appears in U.S. Patent 3,890,408.

' ~::
~ ' WO93/2~120 PCTJUSg3/0~472 9 ~ 8 - 2 -In a further dev~lopment of this chemistry, organolithium initiators containing vinyl unsaturation have been used to initiate polymerization of anionically polymerizable monomer~
S to produce vinyl terminated macromolecules which may be then used as a macromeric component in the preparation of copolymers by ionic or free radical polymerization techniques to produce graft copolymers containing the vinyl macromonomer which provides the pendant graft chains. For example, U.S. Patent ~o. 3,235,626 to Waack, assigned to Dow : Chemical Company, describes a method for preparing graft copolymers of controlled branch configuration.
It is described that the graft copolymers are prepared by first preparing a prepolymer by reacting : a vinyl metal compound with an olefinic monomer to o~tain a vinyl terminated prepolymer. After protonation and catalyst removal, the prepolymer is dissolved in an inert solvent with a polymerization catalyst and is thereafter reacted wiSh either a different polymer having a reactive vinyl group or a : different vinyl monomer under free-radical conditions.
This art suffers from two major limitations:
1) Though the use of vinyl lithium guarantees that ea~h polymer chain has one vinyl end group, it is recognized and documented in the literature, such as R. Waack et al~, Polymer, ~ol. 2, pp. 365-366 ~, , (1961) and R. Waack et al. J. org. Chem., Vol. 32, pp. 3395-339g (1967), that vinyl lithium is one of the slowest anionic polymerization initiators. This slow initiation rate when used to polymerize styrene produces a polymer having a broad molecular weight distribution (Mw/Mn greater than 2), as a .
:, W~93/20120 2 1 3 1 9 8 8 PCT/US93/01472 consequence of the ratio of ~he overall rate of propagation of the styryl anion to that of the vinyl lithium initiation. As a result , graft copolymers prepared from these macromonomers cannot have a uniform side chain molecular weight. 2) I~ is well known in the art that substituted vinyl compounds do not generally polymerize to high conversions.
Conversion tends to decrease as the length of the side chain increases. Conversions of 50%, high for most substituted vinyls, will mean that the resulting graft copolymers will contain 50~ of unreacted macromonomer. For most applications this level of ungrafted polymer is unacceptable.
A different apprsach towards the preparation o macromonomers containing terminal unsaturated ~:~ functional groups is also disclosed in the art.
Sumitomo Chemical's Japanese Kokai 50013483-A
discloses olefin copolymers prepared by the Ziegler-catalyzed reaction of ethylene and/or propylene and : 20 polystyrene end-capped with norbornene. The ~; preparation of a styrene-ethylene graft copolymer is described in an example, wherein the po~ystyrene macromonomer is formed by reacting living n-Bu~i ~capped polystyrene with 5-bromomethyl-2-norbornene.
In addition, polystyrene macromonomers capped wit~ a norbornene group ha~e been prepared by ~ coupling a polystyrene anion with 5-bromomethyl ; norbornene in a mixed solvent (Chemical Abstracts No. CAl04 (26) 225321 w, 1986) and these functional polystyrenes have been further disclosed used as a ~ comonomer in the Ziegler-Natta polymerization of : ~ graft copolymers comprising a polyethylene backbone ~ containing grafted polystyréne side chains (Chemical ;~; Abstracts No. CA107(20) 176624y, 1987).

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,

2 13 19 8 8 ~ 4 ~

Functionalized macromolecules are also disclosed by R. Milkovich et al. in U.S. Patent No .

3,989,768 as well as in R. Milkovich et al. J. Appl.
Polym. Sci., Vol. 27, 1982, pg. 4773. This work 5 describes anionic polymerization of a number of monomers with active initiators, tbereby forming monodisperse living polymer chains. These living chains are then~reacted with a wide-range of termination agents to introduce substantially end-functionalized macromonomers. This route clearlyimproves the resulting macromer polydispersity and allows for a broader ranqe of end functionality, but is introduces an uncertainty into the "purity" of the end-funetional groups. One can no longer be assured that~each and every chain has one functional group. For example, the synthesis of norbornenyl-polystyrene in~accordance with the Milkovich journal article involves as~step l, the anionic polymerization of~styrene in benzene using 20 ~ secondary-butyl lithium as initiator. This step, if done~correctly, can be substantially free of termination. However in practice it is usually about 95% free of termination. Step 2 involves introducing ethylene oxide into the~polymerization 25~ vessel to give the alkoxide. ~nce again this is about 95% efficient. Step 3 involves the reaction of 5-norbornene-2-carbonyl chloride with the polystyrene alkoxide. ~his step is perhaps at best 95% efficient. Though each step results by any 30~ ~standards in excellent yields together they represent a polymer that is .95 x .95 x .95 = 86%
end functional~ Analytical techniques still have not reached the level of precision necessary to characterize this level of end-functionality of high , , ~ :

WOg3/20120 PCT/US93/~1472 ` ~ 2131988 molecular weight macromers. The most informative characterization comes from analysis of the graft copolymers produced using these macromers.
Synthesis of the graft copolymers using these macromers was presented in Milkovich U.S. -3,989,768 with very limited graft copolymer characterization ; information. A recent paper, B. Huang et al~, J~ of Polymer Science: Part A: Polymer Chemistry Edition, VoI. 24, 1986, pgs. 2853-2866 utilized the vinyl terminated macromer as described in U.S.
Patent No. 3,989,768 to prepare graft copolymers ~f ethylene and propylene. This work highlights two important points: First that dou~le bond titrations can only give an approximation for end-group functionality and the best accuracy one can hope for is Z0%. Second that the best conversions for vinyl terminated polystyrene~macromonomers with a moderate molecular weight and useful feed compositions (10 to 30% on EP) is 40%.
~ In light of the above work, it is clearly highly desirable to devise a means for preparing ~acromonomers wherein the guaranteed functionality introduced in the initiation step is combined with a more active;polymerization group. Also, in view of the utility of qraft polymers of anionically polymerized macromonomers with alpha-olefin base polymers and particularly in view of the limitations and uncertainties in the prior art methods of preparing them, thére exists an ongoing need for new~
and efficient means of preparation of graft polymers having essentially uniform molecular weight side chains. It is thus an o~ject of this invention to provide novel compounds, novel macromolecules, and novel graft copolymers as well as novel means of ~ -::
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~,~3~3~ -preparation that allow for both rapid initiation of the anionically polymerized macromonomers and maximization of their functionalization for subsequent graft copolymerization.
S SU~MARY OF THE INVEN'rION
The present invention rela*es to the synthesis and use of alkali-metallated alkyl substituted norbornenes as ionic initiators in the polymerization of anionically polymerizable monomers of monomer mixtures such as vinyl or vinylidene monomers. The polymers produced may be characterized as macromonomers containing a single norbornene group at t~e head of the polymer chain.
This initiator provides for rapid initiation as lS compared with propagation and results in high monomer co mersion and provides macromonomers having a very~narrow molecular weight distribution (Mw/Mn -1.25 or less) having 100% terminal norbornene functionality.
20~ The present invention also relates to random gra~t copolymers prepared by copolymerizing the m~cromonomer~described above with one or more monomers normally copolymerizable with norbornene monomeric material using free radical, anionic or 25~ cat~ionic polymerization technigues.
DETAILED DESCRIP~ION OF THE INVE~TION
The broad category of compounds provided in accordance with this invention are al~yl-substituted norbornenes represented the general formula I:

, , ~: ~

, : . , WO93/20120 21 31 9 8 8 PCT/US93l01472 )- CHiX, .

wherein n is o or an in~eger ranging from 1-17, X
and Xl are independently selected from the group 1~ consisting of H, Li, K and Na, provided that where Xl is Li, K or Na, then X i~ H, further provided that where Xl is ~, then n is an integer ranging from 1-17, ~n-l) of the X substituents are also H, and X is Li, K or Na and further provided that ~here n is o, then X1 is Li, X or Na.
These compounds may be generally prepared by contacting dicyclopentadiene with a ~ono-halogen ontaining oleinically unsaturated alkyl compound ~ : containing f rom 3 ~o 20 carbon atoms under Diel~-: : 20 Alder reaction conditions to for~ the ~ddition product which is an alkyl norbornene containing a halogen substituent group on the ~lkyl ch~in. This :~ reaction product may then be reac~ed under specified cQnditions with an alXali metal such a lithium, ~odium or potassiu~ such ~hat the halogen ~tom i~
di~placed to form the al~ali-metallated, alkyl substituted norbornene compound o~ this invention.
Suitable halogen-substituted olefins which ~ay be employed to form the Diels-Alder adduct include allyl bromide, 3-chloro-1-butene, 3-bromo-1-pentene, l-chloro-2 butene, 5-chloro-1-pentene, 3-chloro-1-propene, 4-bromo-1-butene and 2-chloro-1-bute~e.
The prefPrred co~pounds for the purposes of this in~ention are those set forth in formula I

21 3 ~9 8 ~ - 8 ~

above wherein n is o dnd Xl is Li, X or ~a. These are preferred because they are readily synthesized using a relatively inexpensive and available reactant (allyl bromide) and the resulting intermediate alXyl norbornene halide is reco~ered in relatively high yields because of a minimization of side reactions including decomposition and unwanted cycl;.zation reactions. Accordingly while the invantion will be further described with a focus on preferred compounds and their method of preparation, it should be understood that such description is equally applicable to the preparation of other compounds within the scope of formula I above.
The preferred anionic compounds, useful as initiators, provided in accordance with this : invention may be generally described as corresponding to the formula II.

~ 11 ) I

25 ~ wherein X is an alkali metal selected from the-group consisting of lithium, potassium and sodiu~. The preferred metal is lithium since the lithium containing compound can be more readily prepared by :~ simple lithiation of the corresponding 2-halomethyl-:~ 30 5-norbornene compound and is quite soluble in solvents used for anionic polymerization reactions.
The compounds may be typically prepared by a two stage process. In the first stage an allyl halide, preferably allyl bromide, ~ay be reacted W~93t20120 2131988 PCT/US93/01472 f ~.
g with cyclopentadiene to giYe the bicycloheptenyl-2 methyl halide derivative, i.e~, 2-halomethyl-5-norbornene. The reaction may be carried out using cyclopentadiene as a solvent and at a temperature of 5 from about 20 to lOO-C. A second al~ernatiYe first stage process involves refluxing the allyl halide with dicyclopentadiene whereby at high reflux temperatures (170-19o C) dicyclopentadiene dissociates to form cyclopentadiene, which then adds 10 to the allyl halide. Reaction times under either process may vary between 2 and 8 hours. Although stoichiometric guantities or an excess of either reactant may be employed, it is preferred to use a slight excess of the allyl halide reactant.
The crude product of the first stage reaction is then purified using conventional distillation techniques to further separa~e the 2-halomethyl-5-norbornene from unreacted reactant and isomers thereof.
The second stage of the preparation of the compound involves the reaction of lithium, sodium or potassium metal with the 2-halomethyl-5- norbornene ~-~ to form t~e 2-metalomethyl-S-norbornene having the ~; structure of formula I ab~ve. This reaction is ~, ~
conducted in a solvent which is inert under reacting conditions and which is free of materials which are detrimental to the reaction such a water, oxygen, carbon dioxide and/or alcohols. Suitable s~lvents which may be used are aromatic hydrocarbons such as benzene, toluene, xylene, ethyl benzene, t-butyl benzene and the like; s~tuxated aliphatic and cycloaliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, cyclohexane and the l~ke;
aliphatic and cyclic ethers such as dimethyl ether, W O 93/20120 PC~r/US93/01472 2~ 98~ ~

diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, anisole, tetrahydropyran, diglyme and the like. Organic ethers are preferred solvents due to higher rates of reaction in ether medium. The S reaction is best conducted by gradual drop-wise addition of the norbornene compound to a finely divided suspensio~ of the metal present in excess and in solvent. The reaction is preferably conducted at temperatures below O-C, preferably }O below -30-C, and reaction times may vary between about 3 to 8 hours. These reaction conditions are especially important to avoid thermally induced ring cleavage reactions and unwanted addition reactions which can lead to a low yield of the desired product as well as the formation of isomers which are difficult to separate. Under these preferred conditions, essentially all of the bromomethyl norbornene is reacted to give a mixture which is substantially the lithiomethyl norbornene containing 20 ~ less than 5% by weight of unidentified oligomeric products. The reaction product may then be covered by filtering out residual metal particles and removal of the solvent by evaporation. The following examples illustrate the preparation and 25~ ~purification of 2-bromomethyl-5-norbornene, and the lithiation thereof to produce 2-lithiomethyl-5-~ norbornene.

,~, : ::
, ~ "' WO93/20120 2 1 3 1 9 8 8 PCT/US~3/01472 EXAMPLES
Example 1: ~vnthesis of 2-bromomethYl-5-norbornene A 1 liter steel reaction vessel, fitted with a 2000 kpa pressure release safety and a steel plug was used for the Diels-Alder reaction. 264.4 g (4 moles) Dicyclopentadiene (A~drich), 532~4 g (4.4 moles) allyl bromide (Aldrich Gold Label which was : purified by passin~ it t~rough a column containing sodium ~icarbonate then magnesium sulfate), 3.9 g hexadecane (GC internal standard) and 0.5 g ~utylated hydroxytoluene (antioxidant) were placed into the reactor and reacted 6 hours at 180-C. The resulting crude mixture contained 75% 2-bromomethyl-5-norbornene, 9% dicyclopentadiene, 3% allylbromide and unidentified isomers of each.
Exam~le 2: S~nthesis of 2-Bromomethyl-5-norbornene ~: A 1 liter steel reaction vessel, fitted with a 2000 kpa pressure release safety and a steel plug was used for the Diel~-Alder reaction. 264.4 g ~4 20: moles) Dicyclopentadiene (Aldrich), S80.8 g (4.8 :~ moles) allyl bromide (Aldrich Gold Label which was purified by passing it through a column containing sodium bicarbonate then magnesium sulfate), 3.9 g hexadecane (GC internal standard) and 0.5 g BHT were placed into the reactor and reacted 6 hours at ;: 180-C. The resulting crude mixture contained 78% 2-bromomethyl-5-norbornene, 2% dicyclopentadiene, 7%
allylbromide and unidentified isomers of each.
~: Example 3: Purification of 2-8romomethyl-5-nor~ornene -:: The crude reaction mixture from Exa~ples 1 and 2 were combined and purified by two ~istillation ; steps. ~he ~irst distillation was conducted in a 3 : liter 3 neck flask fitted with a nitrogen sweep, a ~3~9~ - 12 - -thermocouple, and an efficient column. The system pressure was kept at 700 mm Hg pressure and the pot temperature was slowly raised to 175-C. Under these conditions the dicyclopentadiene cracked and cyclopentadiene codistilled with the allyl bromide.
When it appeared that no more volatile products were distilling the pressure was dropped and the contents of the flask were flashed into a receiver. This distillate contained 2% dicyclopentadiene, 95% 2-b~romomethyl-5-norbornene and higher boiling un~dentified isomers. This receiver was then fractionally distilled at 13 mm. Several fractions were obtained ranging from g9.8 to 96% 2-bromomethyl-5-norbornene (by GLC) giving an overall pur~fied yield of 60%.
Example 4: Lithiation of 2-bromomet~vl-5-norbornene A 2 liter 2 neck flask, fitted with a stirrer a~nd~a septum inlet was assembled in a dry box. 700 ml of diethyl ether (distilled from 20~ ~dibutylmagnesium)~ was placed in the flask along with

4 g lithium (Lithco, ~0.8% sodium, slivered from rod). The flask was stoppered and 5% of a solution of 38 g 2-bromomethyl-5-norbornene was added. As soon as the reaction began the flask was cooled to -25~ ~SO-C~or below. The addlt~on was continued dropwise at -50- over 6 hour period. An aliquot was removed and analyzed by GLC; the bromide was quantitatively converted to 2-lithiomethyl-5-norbornene t90%) 2-methyl-5-norbornene was found after reaction with methanol). The excess lithium was removed by ; passing the mixture through a frit and the ether was removed under vacuum via rotary evaporation at - -SO'C. The 2-lithiomethyl-5-norbornene (LMNB) was W~93/20120 21 31 9 8 8 PCT/US93/01472 redissolved in cyclohexane to give a solution that was approximately l molar in organolithium.
Living polymers are conveniently prepared by contacting an anionically polymerizable monomer or mixture of monomers with the lithiomethyl norbornene : compound prep red as above in t~e presence of an organic solvent which does not participate in or interface with the polymerization reaction. The living polymers prepared in accordance with this invention using LMNB as an initiator may ~e generally characterized by the structure III:

: ~,/C~2~ P~ H

wherein ~ represents a linear polymeric chain which ~ may be a homopolymer, random copolymer or block copolymer derived from anionically polymerizable ~onomeric material. This structure is in contrast to prior polymers prepared by coupling a living polymer prepared using a butyl l~thium initiator 25 : capped by a termination reaction with a norbornene alkyl halide such as disclosed in U.S. patent :3,862,077 and the Chemical Abstract publications cited above and represented by the structure:

C1 13CHL(CHJ C~ ~ P~ CH,.~

WO~3~20120 PCT/US93~01472 ~3~9~ - 14 -Those monomers susceptible to anionic polymerization are well-known and the present invention contemplates the use of all anionically polymerizable monomers. Non-limiting illustrative species include vinyl aromatic compounds, such as styrene, alpha-methylstyrene, viny} toluene and its isomers; Yinyl unsaturated amides such as acrylamide, methacrylamide, N,N-dialkyl acrylamides, e.g., N,N-dimethylacrylamide; acenaphthalene; ~-acrylcarbazole; acrylonitrile and methacrylonitrile,organic diioscyanates including lower alXylene, phenylene and toluene diisocyana~es; lower alkyl and : allyl acrylates and methacrylates, including methyl, t-butyl acrylates and methacrylates; lower olefins, ~ lS such as ethylene propylene, butylene, isobutylene, ;~ pen~ene, hexane, etc; vinyl esters of aliphatic carboxylic acids such as vinyl acetate, vinyl propionate, vinyl octoate, vinyl stearate, vinyl benzoate; vinyl lower alkyl ethers; vinyl pyridines, vinyl pyrrolidones; and dienes including isoprene and butadiene. The term "lower" is used above to denote organic grsups containing 8 or fewer carbon atoms.~ The preferred olefinic containing monomers are conjugated dienes containing 4 to 12 carbon atoms per molecule and the vinyl-subs~tuted aromatic ~ydrocarbons containing up to about 12 carbon atoms.
Many other monomers suitable for the preparation of the side chains by anionic ~: 30 polymerization are those disclosed in macromolecular Reviews: Volume 2, pages 74-83, Interscience ~:: Publishers, Inc. (1967~, entitled "Monomers Polymerized by Anionic Initiators, n the disclosure of which is incorporated herein by referenc~.

W(~93/20120 21 31 g 8 8 P(~r/US93/01472 The first step of this process is carried out by reacting a mono-functional lithium metal compound system with the respective monomer or monomers to form the living polymer chain P-Li. This polymerization step can be carried out in one step or in a sequence of steps. In the case where the polymer chain P is a homopolymer or a random or tapered copolymer of two or more monomers, the monomers are simultaneously polymerized with the lo lithium metal initiator. In the case where the polymer chain P is a block copolymer comprising two or more homo- or copolymers blocks, these individual blocks can be generated by incremental or sequential monomer addition.
An inert solvent generally is used to facilitate heat transfer and adequate mixing of initiator and monomer Hydrocarbons and ethers are the preferred solvents. Solvents useful in the anionic pol~merization process include the aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, t-hutylbenzene, etc.
~; Also suitable are the saturated aliphatic and cycloaliphatic hydrocarbons such as n-hexane, n-heptane,-n-octane, cyclohexane and th~ like. In addition, aliphatic and cyclic ether solvents can be used, for example, dimethyl ether, diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, anisole, ; tetrahydropyran, diglyme, glyme, etc. The rates of polymerization àre faster in the ether solvents than in the hydrocarbon solvents.
The amount of initiator is an important factor ~; in anionic polymerization because it determines the molecular weight of the living polymer. If a small proportion of initiator is used, with respect to the , WO93/20120 PCT/US93/0~472 2~-3~

amount of monomer, the molecular weighS of the living polymer will be larger than if a large proportion of initiator is used. Generally, it is advisable to add initiator dropwise to the monomer ~when that is the selected order of addition) until the persistence of the characteristîc color of the organic anion, then add the calculated amount of initiator for the molecular weight desired. The preliminary dropwise addition serves to destroy contaminants and thus permits better control of the pol~merization.
To prepare a polymer of narrow molecular weight distribution, it is generally preferred $o introduce all of the reactive species into the system at the same time. By this technique, polymer growth by : consecutive addition of monomer takes place at the same rate to an a~tive terminal group, without chain transfer or termination reaction. When this is accomplished, the molecular weight of the polymer is controlled by the ratio of monomer to initiator, as described in the: formula: Molecular weight of living polymer = (Moles of Monomer/Moles of ~ Initiator) x Molecular weight of Monomer.
-~ ` As it can be seen from the above formula, high ~ 25 concentrations of initiator leads to the formation -`~ of low molecular weight polymers, whereas, low concentrations of initiator leads to the production of high molecular weight polymers.
The concentration of the monomer charged to the reaction vessel can vary widely, and is limited by the ability of the reaction equipment to d~ssipate the heat of polymerization and to properly mix the ~: resulting viscous 501utions of t~e living polymer.
~; Concentrations of monomer as high as 50 percent by ,~,~.~

weight or higher based on the weight of the reaction mixture can be used. However, the preferred monomer concentration is from about 5 to about 2S percent in order to achieve adequate mixing.
As can be seen from the formula above and the foregoing discussion on the concentration of the monomer, the initiator concentration is critical, but may be varied according to the desired molecular weight of the living polymer and the relative : 10 concentration of the monomer. Generally, the initiator concentration can range from about 0.0001 to about 0.1 mole of active alkali metal per mole of monomer, or higher. Preferably, the concentration of the in-~iator will be from abou~ 0.01 to about :~ 15 0.004 mole of active alkali metal per mole of monomer.
The temperature of the polymerization will ~: : depend on the monomer. Generally, the reaction can be carried out at temperatures ranging from about -lOO-C. When using aliphatic and ~ydrocarbon solvents, the preferred temperature range is from about -lO C to about lOO-C. ~ith ethers as the solvent, the preferred temperature range i5 from about -100-C to about 100-C. The polymerization of 2S styrene monomer, for example is gener~lly carried out at slightly above room temperature,: the polymerization of alpha-methylstyrene monomer preferably is carried out at lower temperatures, e.g., -80-C.
: 30 The preparation of the living polymer can be carried out by adding a solution of the al~ali metal hydrocarbon initiator in an inert organic solvent to a-mixture of monomer and diluent at the de~ired polymerization temperature and allowing the mixture WO93/20120 PCT/US93/01472i 2~ 6 to stand with or without agitation until the polymerization is completed. An alternative procedure is to add monomer to a solution of the catalyst in the diluent at the desired polymerization temperature at the same rate ~hat it is being polymerized. By either method the monomer is converted quantitatively to a living polymer as long as the system remains free of impurities which inactivate the anionic species. As pointed out above, however, it is preferred to add all of the reactive ingredients together rapidly to insure the formation of a uniform molecular weight distribution of the polymer.
The anionic polymerization must be carried out; lS under carefully controlled conditions so as to exclude substances which destroy the catalytic effect of the catalyst or initiator. For example, such impurities as water, oxygen, carbon monoxide, carbon dioxide, and t~e like should be excluded from the system. Thus, the polymerizations are generally carried out in dry equipment, using anhydrous reactants, and under an inert gas atmosphere, such as nitrogen, helium, argon, methane, and the like.
The above-described living polymers are susceptible to further reactions including further polymerization. Thus, if additional monomer, such as styrene, is added to the liYing styryl polymer, the polymerization is renewed and the chain grows until no more monomeric styrene remains.
Alternatively, if another different anionically polymerizable monomer is added, such as butadiene or ethylene oxide, the above-described living polymer ; initiates the polymerization of the butadiene or ;~ ethylene oxide and the ultimate living polymer which W~3~20120 ~ 21 31 9 88 PCT/US93/81472 ~ ..

results consists of a polystyrene segment and a polybutadiene or polyoxyethylene segment.
A poly(styrene-ethylene) block copo}ymer can be prepared by contacting living polystyrene with ethylene in the presence of a compound of a transition metal of Group V-YIII in the periodic table, e.g., titanium tetrachloride. This technique is also applicable to other alpha-olefins such as propylene, butene, etc. The resulting copolymer is still a living polymer and can be terminated by the methods in accordance to the practice of the present invention.
As noted above, the living polymers employed in the present invention are characterized by relatively uniform molecular weight, i.e., the distribution of molecular weights of the mixture of living polymers produced is quite narrow. This is in marked contrast to the typical polymer, where the molecular weig~t distribution is quite broad. The ~ 20 difference in molecular weight distribution is ;~ particularly evident from an analysis of the qel permeation chromatogram of commercial polystyrene (Dow '666~ prepared by free-radical polymerization and polystyrene produced by the anionic ~polymerization process utilized in accordance with the practice of the present invention.
After the desired degree of polymerization is reached, the polymerization is terminated by contact of the ionic polymer with agents containing active ; 30 hydrogeA (proton donors) such as water, alcohsls, aqueous acid solutions or mixtures ther~of. An antioxidant such as butylated hydroxytoluene (~HT) may- also be added to the reaction mixture before isolation of the final polymer.

.

W093/20120 PCT/US93tO1472 ~3~9~8 20 -The molecular weight ~Mw) of the living polymers produced in accordance with this invention may generally range from about l,OOO up to about 2, 000, 000 preferably from about 5,000 up to about

5 500,ûOO and most preferably from about lO,ObO up to abo~lt l50,000, As stated above, 2-lithiomethyl-5-norbornene provides for rapid initiation of the : anionic reaction mechanism thereby leading to :~ poly~ers having a very narrow molecular weight distribu~ion (Mw/Nn) of less than l.25, generally in the order of 1.1 or less. As such, ~e polymers have enhanced mechanical and processing properties.
The following examples illustrates t~e preparation of a 2-polystyryl-~-norbornene polymer having the structure of formula IV:

~

`~ IV
wherein n is an integer sufficient to provide a poly~er molecular weight of about 5,000 ~o about 75,000; generally in the range of from about n = 50 :: to n = 600.
All reactions and reagents were handl d under an inert atmosphere of nitrogen with careful exclusion of both oxygen and water. The monomers were purified by distillation within a day of ; : polymerization from dibutylmagnesium. The solvent (heptane, cyclohexane, ether or tetrahydrofuran) was purified the day of the polymerization by distillation under nitrogen of 25% of the total volume or alternatively by vacuum distillation from butyl lithium. The monomer was added to the solvent just prior to use. All glassware, syringes and needles were oven dried at 150-C for 3 hours. The hot glassware, syringes and needles were oven dried at 159-C for 3 hours. The hot glassware was cooled and assembled under inert atmosphere usually in a dry box.
Example 5: Pre~aration of 2-lPolystyryl)-5-norbornene A 3 liter flask was fitted with a magnetic stirring bar and filled with 2800 ml cyclohexane.
The flask -~as heated and 600 ml cyclohexane was distilled and the flask was cool d. 250 g freshly ~; distilled styrene ~from di~utylmagnesium) was added : along with 80 ml of the 2-lithiomethyl-5-norbornene solution from Example 4. The polymerization began instantaneously and the flask temperature rose from 35-C to 55-C at which temperature it was maintained for 3 hours. The polymerization was terminated with methanol vapor and 0.1 g BHT was added ~efore the polymer was isolated by precipitation in isopropanol.~ The resulting norbornene terminated polystyrene (240 g) had a Mw = 6600, Mn = 5700 and Mw/Mn = 1.1.
Example 6: PreParation of 2-fPolYstvryll-5-norbornene The experiment was repeated as in Exa~ple 5.
This time 99 g of styrene was reacted with 3 ~1 2-lithiomethyl-5-norbornene. The resulting pol~mer (8S g) has a Mw of 73,000, and Mn of 69,00 and a Mw/Mn of 1. a6.

:

. ~, Nor~ornene is a very reactive monomer, in many cases ~s reactive as ethylene, and may therefore be readily copolymerized with other monomers in ree radical, anionic and cationic polymerization systems, as well as in extruder graft reactions.
This characteristic allows the utilization of the norbornene-capped macro~onomers of this invention in similar copolymerization reactions for the preparation of random graft copolymers containing I0 the norbornene head monomer as part of the copolymeric backbone chain and the polymer associated therewith present as graft polymer segments of essentially uniform molecular weight pendant from the backbone chain, such as recurring 15 polymer units represented by the structure Y:

}
C ~2 \
~ ~ \c~ ~P~H
:: V
wherein Pl represents a polymer or copolymer segment 2S deri~ed from a monomer or mixtures of monomers copolymerizable with norbornene-type monomers and P
is as described above.
The preparation of such graft copolymers , provides thermoplastic polymer compositions having balanced beneficial properties of both the P and P
polymer components alone and provides a technique for chemically linking these polymers with might o~herwise be mutually incompatible when physically mixed or grafted by other techniques. The present WO93/20120 2 1 3 1 9 8 8 PCT/USg3/0147~
~ .

graft copolymers differ structurally from conventional graft copolymers since the macromolecular monomer is interposed between polymeric segments of the backbone polymer rather than being arbitrarily attached to the backbone in a : random manner. These characteristics contribute materially to the advantageous properties which inure in these novel graft copolymers.
~ ~ The backbone component of the graft copolymers~ . 10 of the present invention may be derived from any ethylenically unsaturated monomer which is :~ copolymerizable with norbornene-type moncmer materials. These include alpha-olefin monomers containing frcm 2 to about 8 carbon atoms such as lS ethylene, propyle~e, l-butene, isobutene, 1-pentene, hexane, and the like as well as ~ixtures of : ethylene and one or more of said olef ins . Also include are diolefin monomers such as butadiene, :::
isoprene, piperylene and other conjugated dienes as well as mixtures of olefin and diolefin mono~ers such as isobutylene and isoprene which can be used to make so called butyl rubber; mixtures of ; butadiene or isoprens an vinyl aromatic monomers ~ such as styrene or other vinyl monomers such as :~ : 25 acrylonitrile or lower alXyl (meth) acrylates.
Other monomers which may be employed in preparing the backbone polymer includa the acrylic acids, their esters, amides and nitriles including acrylic acid, methacrylic acid, the alkyl esters of acrylic and methacrylic acid, acrylonitrile, ~: methacrylonitrile, acrylamide, methacrylamide, ~: N,N-dimethacrylamide; the vinyl halides such as vinyl chloride, and vinylidene chloride; the vinyl cyanides such as vinylidene cyanide; vinyl esters , .

WO93/20120 PC~/US93/0147~

~3~9~

such as vinyl acetate, vinyl propionate and vinyl chloroacetate, etc, and the vinylidene containing dicarboxylic anhydrides, acids an esters, fumaric acid and esters, maleic anhydrides, acids and esters thereof.
Particularly preferred backbone monomer material includes ethylene, propylene, isobutene, mixtures of ethylene and alpha-olefins including propylene, butene, pentene, hexane, heptene, octene, alkyl acrylates or methacrylates wherein the alkyl group c~ntains 1 or 2 carbon atoms and conjugated diolefins such as butadiene or isoprene, alone or mixed with a vinyl monomer such as styrene, acrylonitrile or a lower alkyl acrylate or ~;~ 15 methacrylate. Especially preferred bacXbone monomer ~: is a ~ixture of ethylene and propylene present at a level such that the copolymer bacXbone contains fro~
: about lS to about 80 mole percent polymerized ethylene, the balance being propylene and the interpolymerized norbornene head monomer of the - macromonomer.
Ths weight average molecular weight of the graft copolymers prepared,in accordance with this invention may generally range from about 10,000 up 2S to about 3,000,000, more preferably in the range of from about 19,000 up to about 250,000.
The copolymerization of the polymerizable macromolecular monomers with the comonomers may be conducted in a wide range of proportions. Generally speaking, a sufficient amount of the ~acromolecular monomer should be present to provide the chemical joining of at least one of the uniform molecular weight side chain polymers to each backbsne polymer, so that a noticeable effect on the properties of the WO93~20120 2131988 PCT/USg3/01472 graft opolymeric properties can be ob~ained. Since the molecular weight of the polymerizable ..
macromolecular monomer generally exceeds that of the polymerizable comonomers, a relatively small amount of the polymerizable macromolecular monomer can be : employed. However, chemically joined, phase separated thermoplastic graft copolymers may be prepared by copolymerizing a mixture containing up to about 95 percent by weight, or more, of the polymerizable macromolecular monomers of this invention, although mixtures containing up to about 60 percent by weight of the polymerizable ~: macrom~lecular monomer are preferred. Stated, otherwise, the ~esinous thermoplastic chemically j~oined, phase separated graft copolymer of the invention is comprised of (l~ from l to about 95 :~ ~ percent by weight of the polymerizable macro~olecular monomer having a narrow molecular : weight distribution (i.e., a Mw/Mn of less than l.l); and (2~ and from 99 to about 5 percent by weight of a copolymerizable comonomer or mixture of comonomers de~ine herein above.
The polymerizable macromolecular monomers copolymerize with the herein above referred to comonomers in bulk, in solution, in aqueous suspension and in aqueous emulsion systems suitable for the particular polymerizable macromolecular :~ monomer, its end group and the copolymer employed~
a catalyst is employed, the polymerization environment suitable for the catalyst should be employed. For example, oil-or solvent-soluble peroxides such as benzoyl peroxide are generally effective when the polymerizable macromolecular monomer is copolymerized with a ethylenically WO93/20120 . PCT/US93/01472~

'l,'~-'3~9~

unsaturated comonomer in bulk, in solution in an organic solvent benzene, cycloh~xane, hexane, toluene and the like, or in aqueous suspension, water solub~e peroxîdes such as such as sodium, potassium, lithium and ammonium persulfates are useful in aqueous suspension and emulsion systems.
In the copolymerization of polymerizable macromolecular monomers and a polystyrene, polyisoprene or polybutadiene repeating unit, an . lo emulsifier or dispersing agent may be employed in aqueous suspensions systems. In these systems, ~ particular advantage can be achieved by dissolving :~ the water-insoluble polymerizable macromolecular monomer in a small amount of suitable solvent such as a:hydrocarbon. By this technique, the comonomer ' copolymerizes with the macromolecular monomer in the solvent, in an aqueous system surrounding the solvent-polymer system. Of course, the polymerization catalyst is chosen such that it will be soluble in the organic phase of the :: polymerization system.
As previously stated, various different catalyst systems can be employed in the present : invention for the copolymerization process. For example, ethylene polymerizes under free-radical, ~::: cationic,and coordination polymerization conditions;
propylene and higher alpha-olefins snly polymerize under coordination polymerization conditions;
isobutylene only polymerizes under cationic:~ ' 30 polymerization conditions; the dienes polymerize by free-radical anionic and coordination polymerization conditions; styrene polymerizes under free-radical, cationic, anionic and coordination conditions; ~inyl chloride polymerizes under free-radical and WO93/20120 PCT/US~3/01472 coordination polymerization conditions; vinylidene chloride polymerizes under free-radical polymerization conditions: vinyl fluoride polymeri~es under free-radical conditions:
tetrafluoroethylene polymerizes under free-radical and coordination polymerization conditions; vinyl ethers polymerize under cationic and coordination polymerization conditions; vinyl esters polymerize :~ under free radical polymerization conditions:
acrylic and metacrylic esters polymerize under free-radical, anionic and coordination polymerization conditions; and acrylonitrile polymerizes under free-radical, anionic and coordination polymerization conditions.
}5 It will be understood by those skilled in the art that the solvent, reaction conditions and feed rate will be partially dependent upon the type of catalyst system utilized in the copolymerization process. One of the considerations is that the ma~romolecular monomer be dissolved in the solvent system utilized.
It is not necessary, however, for the monomer " ~
feed to be soluble in the solvent system.
Generally, under these conditions during the formation of the copolymer, the graft copolymer will precipitate out of the solvent wherein it can be recovered by techniques known in the polymer art.
The temperature and pressure conditions during the copolymerization process will vary according to the type of catalyst system utilized. Thus, in the ;~ production of low density polyolefin backbones under ~: ~ free-radical conditions, extremely high pressures will be employed. On the other hand, the high density substantially linear polyolefin bac~one WO93/20120 . PCT/US93/01472 ~3~9~ - 28 -polymers produced by the coordination type catalyst generally will be prepared under moderately low pressures.
When preparing graft copolymers having a polyolefin backbone of ethylene or propylene together with a macromolecular monomer, it is preferred to employ a coordination catalyst known in the art as-the Ziegler catalyst and Natta catalysts, the latter being commonly used for polypropylene.
Some of these catalysts are disclosed in Belgian Pat~ No. 533,362, issued May 16, 1955, and U.S.
Patent Nos. 3,113,11S and 3,257,332 to Ziegler et al. These catalysts are prepared by the interaction of a compound of transition metals of group IV-VII
in the period table, the catalyst and an organometallic compound derived from group I-III
metals, as co-catalyst. The latter are co~pounds such as metal hydrides and alkyls capable of giving rise to hydride ions or carbanions, such as trialkyl aluminum. Compounds of the transition elements have a structure with incomplete d-shells and in the : lower valence states, can associate with the metal alkyls to for~ complexes with highly polarized bonds. Those elements are preferably titanium, 25 chromium, vanadium, and zirconium. They yield the ~ best Ziegler catalysts by reaction of their : compounds with metal alkyls.
As previously stated, the solvent system utilized will most conveniently be the solYent employed in the preparation of the macromolecular ~; ~ monomer. Solvents useful for the polystyrene : ~ : macromolecular monomers are those which dissolve polystyrene. Typical solvents for polystyrene .
:

WO93/20120 2 1 31 ~ 8 8 PCT/USg3/0147~
....

include cyclohexane, benzene, toluene, xylene, decalin, tetralin and the like. --The polymerization reaction may be conducted atany suitable temperature, depending on the particular catalyst, macromolecular monomer feed, resulting gr~ft copolymer and solvent used.
Generally, the graft copolymerization will be conducted at a temperature of from about lO-C to about SOO-C, preferably from about 20-C to about 100 C.
The graft copolymerization reaction is preferably conducted by placing a predetermined .
amount of the macromolecular monomer dissolved in the appropriate solvent in the reactor. The polymerization catalyst and monomer are thereafter fed into the sol~ent system to produce the graft copolymer.
It is generally desirable to provide a graft copolymer having at least about 2 percent ~ macromolecular monomer incorporated in the backbo~e polymeric material. However, satisfactory results can be obtained with up to about 40 percent by weight macromolecular monomer incor~poration.
The means for providing the proper amount of incorporation of the macromolecular monomer can be ~,~ determined;simply~by adding the appropriate weighed macromolecular monomer used in the copolymerization ; process. For example, if a graft copolymer having lQ percent by weight incorporation of the `~ 30 macromolecular monomer into the backbone polymer is ; desired, one simply employs lO parts by weight of the macromolecular monomer for each 90 par,ts by weight of the monomer feed.

;:

~3~9~ - 30 -Following the procedures outlined a~ove, graft copolymers having unique combinations of properties are produced. These uniqus combinations of properties are made possible by the no~el process herein which provides for compatibility of otherwise incompatible polymeric segments. These incompatible segments segregate into phases of their own kind.
The chemically joined, phases separated graft copolymers of the invention microscopically possess a controlled dispersion of the macromolecular side chain in one phase (domain) within the backbone polymer phase (matrix). Because all of the macromolecular monomer side chain domains are an integral part or interposed between large segments of the ba~kbone polymer, the resulting graft copoIymer will have the properties sf a cross-linXed polymer, if there is a large difference in the Tg or Tm of the bac~bone and side chain segments. This is ~ ~ true only up to the temperature required to break ;~ 20 the thermodynamic cross-link of the dispersed phase.
In essence, a physically cross-linked (as opposed to chemical cross-linked) type polymer can be made that -is reprocessable and whose properties are established by simple cooking, rather than vulcanization or chemical cross-linking.
Although, as indicated, tbe graft copolymers herein are characterized by a wide variety of physical properties, depending on the particular monomers used in their preparation, and also on the 0 molecular weights of the various polymer segments within a particular graft copolymer, all of these graft copolymers are useful, as tough, flexible, i~ .
self-supporting films. These films may be used as food-wrapping material, protective wrapping for :

W~93/20120 PCT~US93/01472 ~-~ ` 2~31988 merchandise displayed for sale, molded articles having improYed impact strength and like applications.
Graft copolymers of the macromolecular monomer, S polystyrene, with ethylene-propylene, isobutylene, or propylene oxide monomers have been found to be stable materials that behave like vulcanized rubbers, but are thermoplastic and reprocessable.
Thus, an extremely tough, rubbery plastic is obtained without the inherent disadvantages of a vulcanized rubber. These copolymerized rubber-forming monomers with the macromolecular monomers of the present invention have the acditional use as an alloying agent for dispersing additional rubber for impact plastics.
Just as metal properties are improved by alloying, so are polymer properties. By adding the appropriate amount of an incompatible material to a plastic in a microdispersed phase, over-all polymer properties are lmproved. A small amount of incompatible polybutadiene rubber correctly di~spersed in polystyrene gives high impact polystyrene. The key to this microdispersion is a small amount of chemical graft copolymer that acts as a flux for incorporating the incompatible rubber.
In a similar manner, a copolymer of the macromolecular monomer of the present invention can be flux for incorporating or dispersing incompatible polymers into new matrices making possible a whole new line of alloys, impact ~ plastics, malleable plastics and easy-to-process ; plastics.
The following example illustrates the synthesis ;; of an ethylene propylene copolymer and a series of WOg3/20120 PCT/US93/01472 ~3~9~ - 32 --ethylene/propylene/graft (2-polystyrene-5-norbornene) polymers by a continuous process using a continuous flow stirred tank reactor and a Ziegler catalyst system.
S Example 7: Synthesis of Terpolymer of Ethylene-Propylene-(2-Polystyrene-5-Norbornene~
Reactor Conditions:
Reactor 1 Liter CFSTR
Temperature 30~C
::~ 10 Pressure 500kpa Agitation 1200kpa Residence 9 min : Feeds:
~oluene 4.11 kg/hr Ethylene 95 g/hr ~ : Propylene 138 g/hr -~ 2-polystyryl-5-norbornene Condition A 0 g/hr Condition B 5.63 g/hr Condition C 11.26 g/hr :: Condition D 16.8~ g/hr Condition E 22.52 g/hr ; Hydrogen 0 wppm on Ethylene VCI4 0-493 g/hr Ethyl aluminum sesquichloride PolYmer Characterization:
Condition A B C D E
Polymerization Rate(gms/hr)210 207 202 208 210 : 30 Ethylene wt%( ~ 48 49 45 42 40 PS wt% (2) 0 8 11 15 19 . Mn by GPC 107k 112k lllk106k 106k : Mw by GPC 174k 184k 182k172k 171k Tensile (psi)10 70 190 640 850 3~ % Elongation40Q 560 720 820 870 , Notes: ~l)Ethylene content determined by ASTM 1246 2)PS content is the weight percent of the incorporated 2-polystyryl-5-norbornene as determined by GPC.

' W~93/20120 2 1 3 1 ~ 8 8 PCT/US93/01472 Monomer con~ersion for t~is monomer is uniformly a~ove 85% for ~his monomer under these polymeriza~ion conditions.
The distribution of the polys~yrene grafts in the poly was determined by analyzing an aliquot of the polymer by gel permeation chromatography. The eluant of the chromatograph column was analyzed and a W detector at 254nm which reveals the presence of styrenic residues. In all cases the responses of these two detectsrs were coinciden~ indicating that : the styrenic residues are incorporated in the polymer.
The graft copolymers prepared in example 7 : above are clear tough thermoplastic elastomers.
Transmission ele~tron micrographs of the grafts indicate that they are microphase separated with spherical polystyrene domains averaging 30 anometers. The rheology of the graft copolymers is typical for multiphase materials. A temperature sweep rom 200- to lOO-C did not show a large change ~; in viscosity, ~hich indicates t~at the sys~em likely xemains biphasic in the melt. This corresponds to the non newtonian shear behavior. The polymer undergoes a 4 order of magnitude drop in viscosity 25: upon increasing the shear-rate from 10 2 to 10 2 .
~: rad/sec. The mechanical properties of the graft copolymers increase with increasing polystyrene content: the ungrafted EP has no strength.
However, the sample containing 19% qrafted polystyrene had a tensile of 900 psi with an elongation at break of 875%.

:

Claims (25)

1. A composition represented by the formula:

wherein n is 0 or an integer ranging from 1-17, X
and X1 are independently selected from the group consisting of H, Li, X and Na, provided that where X1 is Li, K or Na, then X is H, further provided that where X1 is H, then n is an integer ranging from 1-17 and (n-1) of the X substituents are also H
and X is Li, K or Na, and further provided that where n is 0, then X1 is Li, X or Na.

2. The composition of claim 1 wherein X1 is lithium.

3. A composition having the structure:

wherein X is an alkali metal selected from the group consisting of lithium, sodium and potassium.

4. The composition of claim 3 wherein X is lithium.

5. A process for preparing a composition represented by the formula:

wherein X is lithium, sodium or potassium, comprising:
(a) reacting an unsaturated halide and a compound selected from cyclopentadiene and dicyclopentadiene at a temperature of at least 20°C
to form 2-halomethyl-5-norbornene: and (b) contacting said 2-halomethyl-5-norbornene with an alkali metal in the presence of inert nonprotonic solvents.

6. The process of claim 5, wherein said unsaturated halide is allyl bromide.

7. The process of claim 5, wherein said alkali metal is lithium.

8. The process of claim 5, wherein said product of step (a) is purified by fractional distillation before step (b).

9. The process of claim 5, wherein said alkali metal is present as a suspension of the metal in a solvent and wherein said 2-halomethyl-5-norbornene is gradually added to said solvent suspension maintained at a temperature below 0°C.

10. The process of claim 9, wherein said solvent suspension is maintained at a temperature below about -30°C.

11. A macromonomer represented by the formula:

wherein P represents a polymeric chain selected from the group consisting of homopolymers, random copolymers and block copolymers derived from one or more anionically polymerizable unsaturated monomers or mixtures of said monomers, n is 0 or an integer ranging from 1-17, y and y1 are either 0 or 1, provided that where y1 is 1 then y is 0, further provided that where y1 is o, then n is an integer ranging from 1-17 and (n-1) of the y substituents are also 0, and the remaining y substituent is a 1, and further provided that where n is 0, then y1 is

12. The macromonomer of claim 11, wherein P
comprises a polymer derived from a vinyl aromatic monomer selected from the group consisting of styrene, alpha-mehtylstyrene, 4-propylstyrene, 4-methylstyrene, pure and mixed isomers of dimethylstyrenes, trimethylstyrene, vinylnapthalene, 4-cyclohexylstyrene, vinyl toluene, 1-vinyl-5-hexylnapthalene.

13. The macromonomer of claim 11, wherein P
comprises a polymer of one or more anionically polymerizable monomers selected from the group consisting of acrylates, methacrylates, acrylamides, acrylonitriles, hexamethylcyclotrisiloxane, ethylene oxide and propylene oxide.

14. The macromonomer of claim 12, wherein P
comprises polystyrene, poly(4-methylstyrene) or poly(styrene-co-4-methylstyrene).

15. The macromonomer of claim 14, wherein P has a molecular weight of from about 1,000 to about 50,000.

16. A copolymer comprising the interpolymerization product of one or more ethylenically unsaturated monomers and a macromonomer represented by the formula:

wherein P represents a polymeric chain selected from the group consisting of homopolymers, random copolymers and block copolymers derived from one or more anionically polymerizable unsaturated monomers or mixtures of said monomers, n is 0 or and integer ranging from 1-17, y and y1 are either 0 or 1, provided that where y1 is 1 then y is 0, further provided that where y1 is o, then n is an integer ranging from 1-17 and (n-1) of the y substituents are also 0, and the remaining y substituent is a 1, and further provided that where n is 0, then y1 is 1.

17. The copolymer of claim 16, wherein said unsaturated monomers comprise a mixture of ethylene and propylene.

18. The copolymer of claim 17, wherein the ethylene is present from about 15 to 80 mole percent and said macromonomer is present at from 2 to about 40 percent by weight based upon the weight of the copolymer.

19. The graft copolymer of claim 16, wherein said P
comprises polystyrene, poly(4-methylstyrene) or poly(styrene-co-4-methylstyrene).

20. The copolymer of claim 18, wherein the weight average molecular weight is from about 10,000 to about 3,000,000.

21. The copolymer of claim 18, wherein the weight average molecular weight is from about 10,000 to 250,000.

22. The copolymer of claim 17, prepared by polymerizing said mixture of ethylene, propylene and macromonomer in the presence of a Ziegler coordination catalyst.

23. A process for anionic polymerization of olefins comprising contacting an initiator of 2-litho methyl 5-norbornene with an olefin.

24. The composition of claim 1, used as an anionic polymerization initiator.

25. The process of step 5, wherein the solvent is ether or tetrahydrofuran.