WO2011003832A1

WO2011003832A1 - Polymer or polymer network

Info

Publication number: WO2011003832A1
Application number: PCT/EP2010/059479
Authority: WO
Inventors: Jörg Christian TILLER; Frank Katzenberg; Benjamin Heuwers
Original assignee: Technische Universität Dortmund
Priority date: 2009-07-06
Filing date: 2010-07-02
Publication date: 2011-01-13
Also published as: EP2451628A1

Abstract

The invention relates to a polymer or polymer network (32) comprising crystals in a stressed, dimensionally-stable state, wherein the crystals in the stressed, dimensionally-stable state can tear under the effect of an external cause upon reaching a collaboration threshold, wherein the collaboration threshold can be freely set within a definable range and the crystals present in the stressed, dimensionally-stable state dissolve upon tearing, and the polymer or polymer network (32) cools off during relaxing from the dimensionally-stable, strained state into the unstrained state, that is, below the ambient temperature, and the programming, i.e. the transition of the polymer or polymer network into the stressed, dimensionally-stable state, is possible at room temperature.

Description

Polymer or polymer network

Field of the invention

The invention relates to a stretched, dimensionally stable, polymer or polymer network with endothermic heat of reaction at its relaxation, an article containing the polymer or polymer network, and a process for producing such a polymer or polymer network and the use of such a polymer or polymer network, wherein the polymer or polymer network characterized by special energy storage, sensor, actuator and / or shape stability properties.

Background of the invention

Polymers of suitable configuration are in principle crystallizable. These crystals form by themselves or are induced by an external influence. The melting temperature of these crystals depends essentially on the constitution and configuration of the polymer, but it is also influenced by the size, shape and nature of the crystallites (morphology). The melting temperature varies depending on the morphology only in a small temperature range. Polymer networks are three-dimensionally linked together polymer chains, which are linked together via crosslinking points and crystallization after elongation, the stretched shape can be stabilized.

At the melting temperature of the crystals, the relaxation of the polymer network returns to its original shape. The melting temperature of the crystals in the stretched state differs only slightly from the melting temperature in the fully relaxed state. For a shape change, all crystals must completely conform to a 1st order phase transition melt. This melting temperature thus corresponds to the switching temperature of the shape memory polymers known in the prior art.

The property of the shape memory is not a substance-specific property, but rather results from the structure or the morphology of the materials. For example, the shape memory effects of some metallic alloys and ceramics have been known for a longer time than those of plastics, which, however, have the greatest potential. However, only a few shape memory polymers are described so far, resulting in increased research in this sector.

In this case, a polymer is first brought into its permanent shape by conventional processing methods. By mechanical deformation at temperatures above the melting temperature of the polymer crystals (= switching temperature), the polymer is then deformed and then cooled, thereby obtaining a temporary shape. This process is also called programming. Only by heating the polymer to temperatures above the melting temperature (= switching temperature), this returns to its original shape.

A disadvantage of the known polymers and polymer networks, however, is that the switching temperature of a shape memory polymer system is not adjustable, so that there was previously no way to adjust the shape memory effect of the same material to specific applications exactly.

Furthermore, it is disadvantageous that the known polymers and polymer networks for programming are heated to a temperature above the switching temperature, then stretched and then cooled.

In addition, so far no polymers or polymer networks are known which cool when triggered by a trigger below the ambient temperature and thus are able Permanently store "cold." Description of the Invention

The object of the invention is to provide a polymer or polymer network which is capable of widely varying the switching temperature, hereinafter referred to as the triggering temperature, with respect to the relaxation of a strained, dimensionally stable polymer or polymer network independent of the polymer or polymer network used To be able to set any desired areas and / or permanently store "cold" and / or to switch the shape, and / or the mechanical stress, and / or transparency, and / or the temperature and / or permeation with a trigger, and which is programmable by simply stretching at room temperature.

The object according to the invention is achieved by a polymer or polymer network which is in a stretched, dimensionally stable state, which has a trigger point which can be set as a function of the strain rate and / or the ambient temperature, the trigger point being set within a range which is below the temperature of the theoretical temperature and above ambient temperature, leaving the polymer or polymer network in a taut, dimensionally stable condition, wherein triggering of the trigger ruptures the crystals of the polymer or polymer network, thereby relaxing the strained polymer or polymer network and freeing the polymer or polymer network in the polymer or polymer network Relaxation of the dimensionally stable, stretched state in the unstretched state cools below the ambient temperature.

For the purposes of this invention, dimensionally stable or dimensionally stable state, hereinafter also referred to as dimensionally stable or shape-stabilizing state, in connection with the inventive, stretched polymer or polymer network, means that the polymer or polymer network remains in a stretched state, wherein the strained polymer or polymer network Exposure to an external stimulus can be relaxed. Without wishing to be bound by theory, it is believed that the stretched, rigid polymer or polymer network is at an elevated, energetically stable energy level, such that it requires additional activation energy, also referred to herein as an external stimulus or trigger, for the strained polymer or polymer network is converted into its energetically stable, unstressed state. Without this external stimulus or trigger, the polymer or polymer network according to the invention remains in its tensioned state.

Surprisingly, the polymer or polymer network cools during relaxation from the dimensionally stable, stretched state in the unstretched state significantly. Consequently, the taut, dimensionally stable polymers or polymer networks according to the invention can also be referred to as latent cold storage.

The endothermic heat of reaction of the polymer or polymer network may be further preferred as a result of the rupturing of the crystals and relaxation to the original state> 0.1 J / g to <100 J / g, preferably> 1 J / g to <90 J / g > 5 J / g to <70 J / g and particularly preferably> 7 J / g to <50 J / g.

Relaxation to the original state means for the purposes of this invention that the polymer or polymer network is returned to the unexpanded state.

Triggering of the trigger point in the sense of this invention means that the activation energy necessary for the relaxation from the dimensionally stable, tensioned state into the unstressed state is supplied to the system.

Polymer or polymer networks with rupturable crystals are characterized in that the decomposition of the rupturable crystals at the decomposition point does not take place in the sense of a 1st order phase transition, as for example in the prior art known shape memory polymers is the case.

In the shape memory polymers known in the art, the crystals melt upon relaxation, i. There is a 1st order phase transition.

Surprisingly, it has been found that the stored energy is retained in the polymers or polymer networks stretched according to the invention at or below the trigger point or the triggering temperature exclusively without the use of extrinsic energies, voltages or the like.

In the case of the polymers or polymer networks according to the invention, crystals are present which, by means of triggering an external stimulus, also referred to below as triggers, literally rupture or collapse. When relaxing these stretched polymers or polymer networks with rupturable crystals, surprisingly, cooling of the relaxed polymer or polymer network below ambient temperature is observed.

The polymer or polymer networks according to the invention with rupturable crystals is, so to speak, a latent cold storage.

The shape memory polymers known in the prior art do not have such a property, since the dissolution of the crystals, as already stated above, takes place after a first-order phase transition.

Without wishing to be bound by any particular theory, it is believed that there is an energetic state in which, for example, by a particular manner of carrying out the stretching, a dimensionally stable stress state is formed, in which crystal formation and orientation take place Put crystals under pressure, so to speak. By triggering, for example, an external stimulus, the educated one collapses Crystal system and does not dissolve as expected after a phase transition 1st order, ie the crystals do not melt but tear explosively, resulting in the surprising, significant cooling of the relaxed polymer or polymer network according to the invention. Such latent cold storage, as has been found for the polymers or polymer networks according to the invention, have not yet been described in the prior art.

In the dimensionally stable stress state of the polymers and polymer networks according to the invention, it is assumed that this is an energetically stable state, which differs from that of the shape memory polymers in the stressed state.

To the dimensionally stable, stretched inventive polymer or polymer network in its unstretched, i. due to a relaxed state, it requires an external stimulus. By this external stimulus or trigger, the system is brought out of its energetic rest state, the crystals do not melt in the sense of a 1st order phase transition, but collapse, i. rupture, with the relaxed polymer or polymer network cooling significantly below ambient temperature.

In addition, it has surprisingly been found that the decomposition point of the inventive, stretched polymers or polymer networks can be adjusted over a wide range.

For example, the strain rate can be varied over a wide range by the strain rate, so that one can modulate the decomposition point of the polymer or polymer network of the invention and on the other hand can adjust the latent amount of refrigerant present in the system.

The elongation of the polymer or polymer network in the stretched, dimensionally stable state can be> 30% to <95%, preferably> 40% to <90%, more preferably> 45% to <85%, even more preferably> 50% to <80%, more preferably> 55% to <75% and more preferably> 60% to <70% of the maximum ultimate elongation of the polymer or of the polymer network.

The decomposition point, also referred to below as the triggering temperature, is well below the theoretical melting point of the polymer or polymer network.

As a result of the rupturing of the crystals, the polymer or polymer network cools significantly below the ambient temperature, which is equal to the material temperature, by absorbing the latent heat of fusion. Furthermore, the unconventional decomposition of these crystals allows the decomposition to be triggered without the need for additional heat input equal to the enthalpy of fusion.

According to the invention, it has thus been found that it is possible to produce novel crystal states in polymers and / or polymer networks which lead to the possibility of latent cold storage in the polymers and / or polymer networks, which differ significantly from the physical properties of previously known shape memory polymers ,

The dimensionally stable, stretched polymers or polymer networks according to the present invention have a temperature range in which the rupturable crystals can be torn by a "trigger", without heat and / or energy must be introduced, preferably at least the heat of fusion of> 5 % to <99% of the total of all rupturable crystals, preferably <95% of the total, especially <80% of all rupturable crystals, more preferably <50% of all rupturable crystals, most preferably <20% of all rupturable crystals, more preferably of <10% of all rupturable crystals, and more preferably 5% of the total of all rupturable crystals, of the polymer or polymer network of this invention containing such crystals. The "trigger point" for the purposes of the present invention is a temperature range which is below the temperature at which the rupturable crystals are unstable, and above the temperature at which it is no longer possible, by introducing an external stimulus, the breaking of the Trigger crystals.

The trigger temperature may be below the temperature at which the rupturable crystals become unstable.

In contrast, shape memory polymers produced by the prior art do not have a trigger point in the sense of the features described above.

A triggering temperature of the polymer or polymer network of the invention may be below the temperature at which the rupturable crystals become unstable.

The for forming rupturable crystals suitable polymers or polymer networks according to the present invention may have a rate of crystallization of> 10 ^{~ 7%} / s to <100% / s, preferably of> 10 ^"5% / s to <70% / s, and in particular from> 10 ^"4 % / s to <50% / s.

The stretched, dimensionally stable polymer or polymer network according to the invention with rupturable crystals can be at an ambient temperature of> - 80 ⁰ C to <400 ⁰ C, preferably> - 70 ⁰ C to <350 ⁰ C, more preferably> - 60 ⁰ C to <300 ⁰ C, more preferably> - 50 ⁰ C to <250 ⁰ C, more preferably> - 50 ⁰ C to <250 ⁰ C, more preferably> - 40 ⁰ C to <200 ⁰ C, more preferably> - 30 ⁰ C bis <150 ⁰ C, more preferably> - 20 ⁰ C to <100 ⁰ C, more preferably> - 10 ⁰ C to <80 ⁰ C, more preferably> 0 ⁰ C to <60 ⁰ C, more preferably> 10 ⁰ C to <50 ⁰ C, more preferably> 15 ⁰ C to <45 ⁰ C and even more preferably> 20 ⁰ C to <30 ⁰ C, be formed by stretching the polymer or polymer network. The rupturable crystals can be according to the invention is formed by stretching of the polymer network by the polymer or polymer network made of a unstretched initial state to a stretched state by means of a strain rate of the polymer or of the polymer network of> 10 ^{~ 7%} / s to <10 ^7% / s, preferably from> 10 ^{~ 6} % / s to <10 ⁶ % / s, preferably from> 10 ^"5 % / s to <10 ⁵ % / s, more preferably from> 10 ^{" 4} % / s to <10 ⁴ % / s , more preferably from> 10 ^"3 % / s to <10 ³ % / s, more preferably from> 10 ^{~ 2} % / s to <10 ² % / s, and 10% / s ± 2.

In the polymer or polymer network of the present invention, the rupturable crystals can be formed by, for example, stretching the polymer or polymer network, with the polymer or polymer network in the stretched state having a hold time of> 0 s to <1 d, preferably> 0.05 s to <12 h, more preferably> 0.1 s to <6 h, more preferably> 0.5 s to <3 h, further preferably> 1 s to <1 h, further preferably> 2 s to <50 min, furthermore preferably> 5 s to <40 min, more preferably> 10 s to <30 min, further preferably> 15 s to <20 min, further preferably> 20 s to <10 min, further preferably> 30 s to <5 min, furthermore preferably> 40 s to <2 min, more preferably> 50 s to <1 min., Is maintained.

The rupturable crystals can be according to the invention is formed by stretching the polymer or polymer network wherein the polymer or polymer network from the stretched state to a relaxed state at a relaxation rate of> 10 ^"7% / s to <10 ^7% / s, preferably of>^{10" 6} % / s to <10 ⁶ % / s, preferably from> 10 ^"5 % / s to <10 ⁵ % / s, more preferably from> 10 ^{" 4} % / s to <10 ⁴ % / s, more preferably from > 10 ^"3 % / s to <10 ³ % / s, more preferably from> 10 ^{" 2} % / s to <10 ² % / s, and 10% / s ± 2 and / or the rupturable crystals by cooling of the stretched polymer or polymer network from a temperature above the trigger point to a temperature at or below the trigger point.

In the polymer or polymer network having breakable crystals according to the invention, In the taut, dimensionally stable state of the polymer or polymer network, the crystals may rupture by the action of an external stimulus at the trigger point, whereby the trigger point may be freely adjustable within a definable range.

The inventive polymer or polymer network having breakable crystals may contain at least one or more additives, preferably with> 0% by weight to <70% by weight, preferably> 3% by weight to <60% by weight, more preferably> 5 wt .-% to <50 wt .-%, more preferably> 7 wt .-% to <40 wt .-%, more preferably> 9 wt .-% to <30 wt .-% and particularly preferably> 10 wt % to <25% by weight, based on the total weight of the polymer or polymer network, which are suitable for lowering or increasing the glass transition temperature and / or for increasing or decreasing the crystallization rate of the polymer or polymer network.

According to the invention, it has been found that the range of adjustable trigger points can be widened with the aid of additives which are suitable for lowering or increasing the glass transition temperature of the polymer or polymer network.

This can be particularly advantageous because a free adjustment of the trigger point has not been described within a defmierbaren range according to the prior art.

A further advantage of the polymer or polymer network having rupturable crystals according to the invention can be seen in that upon rupture of the rupturable crystals, the polymer or polymer network cools, inter alia, by absorbing latent heat of fusion. Preferably, the polymer or polymer network may also cool below the ambient temperature of the polymer or polymer network by absorbing latent heat of fusion.

The polymer or polymer network according to the invention is characterized in that it it is possible to produce breakable crystals within the polymer network by special processing of the polymer network. Due to the rupturable crystals, the polymer or polymer network has the surprising effect of a latent cold accumulator compared to the known polymer networks. The polymer or polymer network can be stretched from an initial state, in which the polymer or polymer network has an elongation of 0%, in a stretched state with a strain rate of> 10 ^{~ 7} % / s to <10 ⁷ % / s the stretched state with a holding time of> 0 s to <1 d, preferably> 0.05 s to <12 h, more preferably> 0.1 s to <6 h, even more preferably> 0.5 s to <3 h, furthermore preferably> 1 s to <1 h, more preferably> 2 s to <50 min, further preferably> 5 s to <40 min, further preferably> 10 s to <30 min, further preferably> 15 s to <20 min, further preferably> 20 s to <10 min, more preferably> 30 s to <5 min, further preferably> 40 s to <2 min, further preferably> 50 s to <1 min, and then from the stretched state into a relaxed state at a relaxation rate of> 10 ^{~ 7} % / s to <10 ⁷ % / s are transferred.

As the polymer or polymer network, a variety of materials can be used, wherein for each material within the specified limits for strain rate, hold time, relaxation rate and ambient temperature, the optimum adjustment parameters must be determined by varying the parameters to obtain breakable crystals in a particular amount To produce size and with corresponding trigger points in the polymer or polymer network.

The rupturable crystals are further characterized by the fact that the crystals can rupture upon exposure to an external stimulus upon reaching a Kollabierungsschwelle, wherein the trigger point is freely adjustable within a defmierbaren range. Tearing the rupturable crystals means that the crystals do not melt in the classic sense but are destroyed. In previously known polymers and polymer networks with shape memory properties, the collapse threshold is a material constant which is not achieved by an athermal external stimulus, but only by a thermal stimulus corresponding to the heat of fusion of the crystallites, whereas in the polymer or polymer network of the present invention, the collapse threshold at and The same material is variably adjustable within wide limits and can be achieved by an athermal external stimulus.

Due to the variable adjustability of the collapse threshold or trigger point, the polymer or polymer network according to the invention, independently of its material, can be specially tailored to a large number of applications, so that the potential applications of the polymer network according to the invention considerably increase over known polymer networks.

Shrinkage ratios of up to 15: 1 and / or swelling ratios of up to 1: 5 can advantageously be achieved with the polymer or polymer network according to the invention obtained by the process according to the invention.

The polymer or polymer network having rupturable crystals according to the invention cools when the crystals rupture, among other things by absorbing latent heat of fusion below the ambient temperature of the polymer or polymer network, so that the polymer or polymer network can be used as a refrigerant or cold storage agent.

For the polymer or polymer network can advantageously be used inexpensive renewable raw materials, such as natural rubber.

According to an advantageous embodiment of the invention, the external stimulus as a thermal stimulus and / or a mechanical stimulus and / or a contact with a chemical substance and / or an electromagnetic radiation and / or an electric field and / or a magnetic field and / or a sound and / or a radioactive radiation.

The thermal stimulus can be carried out by supplying heat. The mechanical stimulus can be carried out by stretching or stretching the polymer network located in the taut, dimensionally stable state. Stretching can preferably take place with a degree of stretching of> 1% to <500%, preferably of> 5% to <300%, particularly preferably of> 10% to <100%, from the relaxed state to a stretched state, wherein the stretching should be perpendicular to the chain direction of the molecules in the crystals.

As a chemical substance, chemical substances in the liquid, solid or gaseous state can be used. In particular, solvents or solvent vapors can be used as chemical substances. The external stimulus as electromagnetic radiation preferably takes place with a wavelength of> 1 m to <10 ^"12 m The external stimulus as an electric field preferably takes place with an electric field strength of> 10 V / m to <10 ¹⁰ V / m Stimulus as a magnetic field is preferably carried out with a magnetic field strength of> 10 ^"10 T to <10 T. The external stimulus as sound preferably takes place with a frequency of> 1 Hz to <1 GHz.

The thermal stimulus is preferably triggered by an increase in the ambient temperature above a trigger temperature, wherein the trigger temperature may preferably be variably adjustable in a temperature range physically. The trigger temperature corresponds to the collapse threshold at which the rupturable crystals rupture. The physical setting of the trigger temperature in a variable temperature range preferably takes place by means of the strain rate used in the expansion and / or by means of the ambient temperature prevailing during the stretching. In addition, advantageously, in the polymer or polymer network of the present invention having rupturable crystals, the triggering temperature may be varied physically in a range of temperatures, preferably the level of additive (s) used to lower or increase the glass transition temperature and / or decrease or increase the rate of crystallization of the polymer or polymer network.

The trigger temperature may be in a temperature range of> -80 ⁰ C to <400 ⁰ C, preferably> -50 ⁰ C to <200 ⁰ C, more preferably> -35 ⁰ C to <100 ⁰ C, more preferably> - 25 ⁰ C to <50 ⁰ C and particularly preferably from> 10 ⁰ C to <40 ⁰ C be freely adjustable.

Due to the fact that the trigger temperature can be set as desired physically over a wide temperature range, the field of application of the polymer network according to the invention can be significantly increased and optimally adapted to the corresponding requirements.

The polymer or polymer network according to a further advantageous embodiment of the invention has a net molecular weight of> 500 g / mol to <10 ⁷ g / mol, preferably from> 10 ³ g / mol to <10 ⁵ g / mol, particularly preferably of> 5 * 10 ³ g / mol to <10 ⁴ g / mol, on.

Furthermore, the polymer or polymer network according to the invention which has rupturable crystals preferably has a degree of crosslinking of> 10 ^-3 % to <10%, preferably of> 5 * 10 ^-3 % to <5%, particularly preferably of> 10 ^-2 % to <1 %, on.

More preferably, the polymer or polymer network according to the invention after stretching in the stretched, dimensionally stable, crystallized state, a degree of crystallinity of> 1% to <80%, preferably from> 5% to <50%, particularly preferably from> 10% to <30 %, on.

The crystals present in the stressed, dimensionally stable, state are preferably in the form of lamellar crystals, needle crystals, Shish-Kebab crystals or micelle crystals.

According to the present invention,> 10% to <100%, preferably> 15% to <95%, more preferably> 20% to <80%, even more preferably> 30% to <70%, and most preferably> 40% to <60%, of all crystals, preferably lamellar crystals, needle crystals, and / or micelle crystals, of the polymer or of the polymer network in the stretched, dimensionally stable state in the direction of stretching of the polymer or of the polymer network.

The crystals present in the taut, dimensionally stable state of the polymer or of the polymer network may preferably be lamellar crystals, the lamellar crystals being present in a proportion of> 5% to <100%, preferably> 20% to <90%, more preferably> 30% to < 80%, even more preferably> 40% to <70%, and particularly preferably> 50% to <60%, in the present invention stretched, dimensionally stable polymer or polymer network.

If the crystals present in the taut, dimensionally stable state are in the form of lamellar crystals, the lamellar crystals preferably have a lamella thickness of> 1 nm to <50 nm, preferably from> 3 nm to <30 nm, particularly preferably from> 5 nm to <25 nm, on.

If the crystals present in the taut, dimensionally stable state are in the form of needle crystals, the needle crystals preferably have a needle length of> 10 nm to <2000 nm, preferably from> 15 nm to <1500 nm, particularly preferably from> 20 nm to <1000 nm, on. If the crystals present in the taut, dimensionally stable state are in the form of micelle crystals, the micelle crystals preferably have a micelle size of> 1 nm to <50 nm, preferably from> 3 nm to <30 nm, particularly preferably from> 5 nm to <15 nm, on.

The polymer or polymer network preferably has, in the crystallized state, a modulus of elasticity parallel to the direction of elongation of> 10 MPa to <400 GPa, preferably of

> 50 MPa to <100 GPa, more preferably from> 70 MPa to <1 GPa.

Furthermore, the polymer or polymer network, preferably in the crystallized state, has a tensile strength parallel to the elongation direction of> 1 MPa to <100 MPa, preferably from

> 20 MPa to <80 MPa, more preferably from> 30 MPa to <60 MPa, on.

The polymers selected for the polymer or polymer network should theoretically be crystallizable due to their configuration. Accordingly, the polymers selected preferably have an isotactic, a syndiotactic or a symmetric configuration. The polymer or polymer network preferably comprises at least one or more polymer compound (s) selected from the group of the following polymers: configurationally crystallizable polymers, isotactic polymers, syndiotactic polymers, natural rubber, polyisoprene, polyethylene terephthalate, polycarbonate, isotactic polystyrene, and / or a copolymer.

The invention further relates to a method for adjusting a collapse threshold of rupturable crystals within a polymer or polymer network as set forth above and further comprising the following steps:

A) providing a polymer or polymer network;

B) transferring the polymer or polymer network from an unstretched initial state to a stretched state by means of a strain rate of the Polymer network of> 10 ^{~ 7} % / s to <10 ⁷ % / s, preferably from> 10 ^"6 % / s to <10 ⁶ % / s, preferably from> 10 ^{" 5} % / s to <10 ⁵ % / s , more preferably from> 10 ^"4 % / s to <10 ⁴ % / s, wweeiitteerr bbeevvoorrzzuuggtt vvoonn≥> 10 ^{~ 3} % / s to <10 ³ % / s, more preferably from> 10 ^{" 2} % / s to < 10 ² % / s, as well as 10% / s ± 2;

C) maintaining the polymer or polymer network in the stretched state with a hold time of> 0 s to <1 d, preferably> 0.05 s to <12 h, more preferably> 0.1 s to <6 h, even more preferably> 0 , 5 s to <3 h, more preferably> 1 s to <1 h, furthermore preferred

> 2 s to <50 min, more preferably> 5 s to <40 min, more preferably> 10 s to <30 min, further preferably> 15 s to <20 min, further preferably> 20 s to <10 min, furthermore preferably > 30 s to <5 min, more preferably> 40 s to <2 min, further preferably> 50 s to <1 min;

D) transferring the polymer or polymer network from the stretched state to a relaxed state at a relaxation rate of> 10 ^-7 % / s to -10 ⁷ % / s, preferably from

> 10 ^"6 % / s to <10 ⁶ % / s, preferably from> 10 ^{" 5} % / s to <10 ⁵ % / s, more preferably from> 10 ^" ⁴ % / s to <10 ⁴ % / s, more preferably from> 10 ^"3 % / s to <10 ³ % / s, more preferably from> 10 ^{" 2} % / s to <10 ² % / s, and 10% / s ± 2, wherein in the relaxed state the polymer or polymer network has crystals in a shape stabilizing state;

E) optionally cooling the stretched polymer or polymer network from a temperature above the trigger point to a temperature at or below the trigger point, wherein step E) is executable before, during and / or after step D).

The provided polymer or polymer network is first changed from an unstretched initial state to a stretched state by means of a strain rate of the polymer network of> 10 ^"7 % / s to <10 ⁷ % / s, preferably from> 10 ^{" 5} % / s to <10 ⁵ % / s, more preferably from 10 ^"3 % / s to <10 ³ % / s In this stretched state, the polymer or polymer network is subsequently heated for a certain time, preferably one hour Holding time of> 0 s to <1 d, preferably> 0.05 s to <12 h, more preferably> 0.1 s to <6 h, more preferably> 0.5 s to <3 h, further preferably> 1 s to <1 h, more preferably> 2 s to <50 min, more preferably> 5 s to <40 min, further preferably> 10 s to <30 min, further preferably> 15 s to <20 min, further preferably> 20 s to <10 min, more preferably> 30 s to <5 min, further preferably> 40 s to <2 min, further preferably> 50 s to <1 min held. From the held, stretched state, the polymer or polymer network becomes a relaxed state at a relaxation rate of> 10 ^-7 % / s to <10 ⁷ % / s, preferably from> 10 ^-5 % / s to <10 ⁵ % / s , more preferably from> 10 ^{~ 3} % / s to <10 ³ % / s, wherein in the relaxed state the polymer or polymer network has crystals in a taut, dimensionally stable, state, which by means of an external stimulus exceeds the collapsing threshold of the tearable Rip up crystals.

By means of the method according to the invention, in which a strain-induced crystallization of the polymer network takes place, it is advantageously possible to produce breakable crystals and to be able to freely set the collapse threshold of these crystals in a taut, dimensionally stable, state within a definable range.

In previously known in the art polymer networks with shape memory properties, the collapse threshold is a material constant and not variably adjustable as in the polymer or polymer network according to the invention in one and the same material within wide limits.

Due to the variable adjustability of the collapse threshold, the polymer or polymer network according to the invention, regardless of its material for a large number of applications can be specially tuned, so that significantly increases the potential applications of the polymer or polymer network of the invention over known polymers or polymer networks. The crystals produced by strain-induced crystallization preferably reduce the transparency of the polymer or polymer network at room temperature by a factor of from 1000 to 1.12, preferably by a factor of from 100 to 1.5, particularly preferably by a factor of from 10 to 1 in the wavelength range from 1 dm to 1 nm.

Further, the permeability of the polymer or polymer network to gases and liquids by strain-induced crystallization of metastable crystals at room temperature is preferably reduced by a factor of 10 ⁵ to 1.5, preferably by a factor of 10 ² to 2, more preferably by a factor of 10 to 5 ,

According to a preferred embodiment of the invention, the polymer or polymer network in the relaxed state in step D) has an elongation of> 200% to <1200%, preferably from> 500% to <1100%, particularly preferably from> 700% to <1000%, based on the initial state. The initial state is the state in which the expansion of the polymer network is 0%. Accordingly, it is possible by means of the method according to the invention to generate particularly high strains of the polymer network, without the polymer or polymer network immediately withdrawing to the initial state after relaxation. This happens only when an external stimulus is exerted on the rupturable crystals. Thus, a particularly high dimensionally stable strain of the polymer network is possible, whereby the potential application of the polymer network over known polymer networks is significantly increased.

Further, it is preferably provided that step B) and / or step C) and / or step D) at an ambient temperature of> -80 ⁰ C to <400 ⁰ C, preferably from -10 ⁰ C to <100 ⁰ C, particularly preferably from> 10 ⁰ C to <40 ⁰ C, takes place. The ambient temperature preferably corresponds to the temperature of the material of the polymer network. By means of the ambient temperature, preferably the collapse threshold can be adjusted in a particularly targeted manner, the collapse threshold being variable, independently of the material used for the polymer network, by the choice of the ambient temperature can be adjusted.

Preference is further provided that step C) and / or step D) takes place in the presence of a chemical substance. The presence of a chemical substance makes the production of metastable crystals and the setting of the collapse threshold for these rupturable crystals particularly easy to achieve.

In particular, it may be advantageous to use step C) and / or step D) in the presence of a chemical substance which causes the formation of metastable crystals and / or alters the trigger point, the chemical substance preferably being suitable for changing the glass transition temperature or the crystallization rate, he follows.

The terms "chemical substance" and "additives" are used synonymously.

Chemical substances and additives in the context of this invention include additives and solvents which are suitable for changing the glass transition temperature or the crystallization rate.

Suitable additives may be selected from the group comprising:

Solvents such as chloroform, DMF, ethanol, methanol, xylene, toluene; Plasticizers such as diethylhexyl phthalate (DEHP), dioctyl phthalate (DOP), Mesamoll, alkyl sulfonic acid esters of phenol (ASE), hexamoll, and the like.

The polymer or polymer network according to the invention may contain at least one or more solvents of> 0 wt.% To <20 wt.%, Preferably> 0.001 wt.% To <15 wt.%, More preferably> 0.005 wt <10 wt .-%, more preferably> 0.01 wt .-% to <5 wt .-%, more preferably> 0.05 wt .-% to <3 wt .-%, particularly preferably> 0.1 wt % to <2% by weight, and most preferably> 0.5% to <1% by weight, based on the total weight of the polymer or polymer network, which are suitable for lowering or increasing the glass transition temperature and / or increasing or decreasing the crystallization rate of the polymer or polymer network.

The polymer or polymer network containing breakable crystals according to the invention may contain at least one or more additives, preferably with> 0 wt .-% to <70 wt .-%, preferably> 3 wt .-% to <60 wt .-%, more preferably> 5 Wt .-% to <50 wt .-%, more preferably> 7 wt .-% to <40 wt .-%, more preferably> 9 wt .-% to <30 wt .-% and particularly preferably> 10 wt. -% to <25 wt .-% based on the total weight of the polymer or polymer network, which are suitable for lowering or increasing the glass transition temperature or for increasing or decreasing the crystallization rate of the polymer or polymer network may be added.

The invention further relates to the use of a polymer or polymer network as defined above and further developed as an agent with dimensional modification properties, in particular shrinkage properties and / or elongation properties.

In particular, the invention further relates to the use of a polymer and / or polymer network having rupturable crystals as, in and / or at:

- agents with dimensional change properties,

- swellable material for use as a sealant;

- temperature threshold detector;

- shrink tubing;

- cold storage;

- heat pump;

- actor;

- actuator-sensor combination;

a solvent detector;

- artificial muscle; - stent.

The inventors have found that shape memory polymers may be used to advantage as such or in combination with a polymer or polymer network having rupturable crystals according to the invention, at least for some of the aforementioned uses. This also applies to the following articles.

The invention also relates to an article comprising a polymer and / or polymer network having rupturable crystals and selected from the group comprising:

- agents with dimensional change properties,

- swellable material for use as a sealant;

- temperature threshold detector;

- shrink tubing;

- cold storage;

- heat pump;

- actor;

- actuator-sensor combination;

a solvent detector;

- artificial muscle;

- stent.

The polymer or polymer network according to the invention can be used, for example, as a temperature-sensitive actuator, for example in the form of fire dampers or smoke dampers, which can be closed automatically and without power supply, control or the like by the properties of the polymer network from a set switching temperature.

Furthermore, the polymer or polymer network can be used for medical applications. For example, the polymer or polymer network may be more temperature sensitive Actuator be used for clamping wounds, for example in the form of a belt which is formed from a material having the inventive polymer or polymer network. The belt can be used for example for pinching or constriction of extremities in vein injuries, the polymer or polymer network of the belt, for example, has a trigger temperature of 30 ⁰ C, so that after the application of the belt and after applying the trigger temperature of 30 ⁰ C. pulling the belt independently. It is particularly advantageous that the pressure which the belt is to exert on the wound to be squeezed can be optimally adjusted by varying the duration of the applied trigger temperature, since the duration of the triggering temperature can influence the number of rupturable crystals to be ruptured , so that so that the restoring strain can be adjusted by the collapsed crystals. When a temperature below the tiger temperature is applied to the polymer or polymer network, the tearing of the crystals is stopped, which at the same time means that the recovery strain is stopped.

Further, the polymer or polymer network can be used, for example, as a shrinking agent in the form of a shrink tube, a swellable O-ring or a swellable anchor. In particular, the use of shrink tubing with a particularly large shrinkage is possible. A radially expanded tube made of the polymer or polymer network according to the invention can be stabilized by the strain-induced crystallization according to the invention preferably to its 8-fold to 10-fold diameter or its 8-fold to 10-fold extent. An increase in the temperature of the shrink tube above a previously set trigger temperature initiates the relaxation of the shrink tube, for example, to its initial state. This extremely large shrinkage can be used, for example, for bridging large cross-sectional differences for connecting pipes, in contrast to conventional shrink tubing. For the bundling of cables, the necessary selection of a suitable heat shrinkable tube cross section can be dispensed with and also the threading of the individual cables can be performed be significantly facilitated because a shrink tubing size of the shrink tube according to the invention can cover a very wide range of cross sections. In addition to the thermal inducing of the shrinking process, the shrinking process can also be initiated by a mechanical stimulus, for example in the form of an axial stretching in these heat-shrinkable tubing.

Furthermore, it is possible to use the polymer or polymer network according to the invention as a temperature threshold detector (temperature threshold detector). Such a temperature threshold detector can be used as proof of exceeding a maximum temperature. For this, the polymer or polymer network is crystallized by stretching and the trigger temperature of the resulting rupturable crystals is adjusted so that it is equal to the temperature to be detected. When the trigger temperature is exceeded, the polymer or polymer network of the temperature threshold detector relaxes from a preferably 1000% strain in the relaxed state back to its initial state. Exceeding the trigger temperature can be indicated, for example, by contraction of the temperature threshold detector. In addition, the mechanical energy released in the restoring stretch from the relaxed state to the initial state can be exploited for actuation purposes, for example the adjustment of a pointer, the control or regulation by opening or closing valves or flaps, in which case the temperature -Threshold detector next to the sensory task simultaneously serves as an actuator.

For example, such a temperature threshold detector can be used as a sensor for monitoring refrigerated and frozen chains. The quality of frozen, frozen and refrigerated products is sustainably influenced by compliance with certain maximum temperatures in the cold chain, from the manufacturer of the refrigerated product through the retailer to the end consumer. For this purpose, the temperature threshold detector can be made in the form of a thin film, which is then uniaxially or biaxially stretched and forms tearable crystals in the stretched state. In this stretched state remains the temperature threshold detector until the set trigger temperature is not exceeded. The temperature threshold detector is further provided with a print, for example a seal, which signals compliance with the cold chain. The imprinted temperature threshold detector is then adhered to the cooled product. Before sticking the imprint is preferably provided with a pattern that prevents tampering or even re-groping. When the trigger temperature is exceeded, the temperature threshold detector can contract so much that the imprint is detached from the product or is illegible.

Further, it is possible to use the polymer or polymer network as a solvent detector, in which case the external stimulus is formed by a solvent vapor concentration, for example in the form of chloroform or toluene, which initiates rupture of rupturable crystals within the solvent detector such that a shrinking process is triggered. The shrinking process happens depending on the solvent used above certain temperatures.

Further, it is possible to use the polymer or polymer network as a coolant or as a heat pump, wherein the endothermic heat of about 14 J / g needed to rupture the rupturable crystals can be used for cooling. Regardless of external energy sources, cooling only starts when the adjustable trigger temperature is exceeded. The use of such polymer networks as a coolant can take place, for example, in the form of cooling batteries or cooling compresses. The use of such polymer networks as a heat pump can be done for example in refrigerators or air conditioners. Brief description of the drawings

The invention will be explained in more detail with reference to the accompanying drawings with reference to preferred embodiments.

Show it:

Fig. 1 is a first schematic representation of a first embodiment of a swellable O-ring;

Fig. 2 is a second schematic representation of the first embodiment of a swellable O-ring;

3 is a first schematic representation of a second embodiment of a swellable O-ring;

Fig. 4 is a second schematic representation of the second embodiment of a swellable O-ring;

5 is a first schematic representation of a swellable plug;

FIG. 6 shows a second schematic illustration of the swellable anchor shown in FIG. 5; FIG.

FIG. 7 shows a third schematic representation of the swellable anchor shown in FIG. 6; FIG.

8 shows a schematic illustration of an embodiment of a temperature threshold detector; and

Fig. 9 is a schematic representation of the various states of the invention Political network.

The polymer or polymer network according to the invention is composed of crosslinked polymer chains, with the particularity that the molecular weight of the chain is adjustable in such a way that the network chains can in principle be crystallized with themselves and / or with adjacent network chains. So that no crystallization already begins in the initial state of the polymer network, a polymer must be chosen for the construction of the network, which crystallizes only very slowly, in particular has a crystallization rate of> 10 ^{~ 7} % / s to <10 ^{~ 3} % / s. Only through the stretching of the polymer network and the concomitant stretching and parallelization of the polymer chains within the polymer network crystallization is initiated, are formed in the rupturable crystals within the polymer network. The shortest network chains, which are stretched as the first maximum serve as crystallization nuclei, to which longer networks can attach by means of refolding and thus can form needle crystals, lamellar crystals or micelle crystals. By relaxing the polymer network from the held, stretched state to the relaxed state, the rupturable crystals prevent complete relaxation of the polymer or polymer network. Only by an external stimulus is the collapse threshold of the rupturable crystals achieved, for example by raising the temperature above the triggering temperature at which the rupturable crystals rupture under an intrinsic stress, resulting in complete relaxation of the polymer network to its initial state. However, relaxation-triggering stimuli may also be, for example, mechanical stretching of the polymer network perpendicular to the original direction of elongation, ie the direction of elongation upon transfer of the polymer network from its initial state to the stretched state, or contact with solvents or solvent vapors. The relaxation process in the rupture of the rupturable crystals is accompanied by an endothermic heat of reaction, which leads to a hypothermia of the polymer network well below the ambient temperature. Upon thermal initiation of the relaxation process, ie, a thermal external stimulus, the trigger temperature is in Depending on the ambient temperature during stretching and holding the polymer network and the strain rate in the strain-induced crystallization can be conditioned within wide limits. This allows exact programming of the trigger point of the polymer network to a certain temperature. This is a purely physical conditioning of one and the same material or polymer network, without a change in the chemical configuration of the polymer network.

Based on the multi-faceted properties of the polymer network according to the invention, numerous technologies are conceivable. Areas of application include in particular surgical sutures. Due to the enormously large shrinkage properties of the polymer network and the associated large lateral thickness increases or the exact programmability of the collapse threshold, in particular the trigger temperature, completely new fields of application and product innovations open up.

The polymer or polymer network according to the invention can be used, for example, for swellable sealing rings, such as O-rings, for example, wherein when a certain triggering temperature is exceeded, the sealing ring increases its thickness permanently and thereby still existing or newly formed sealing gaps can be closed. Fig. 1 and Fig. 2 show a swellable O-ring 10 made of the polymer or polymer network according to the invention, which swells when exceeding a certain trigger temperature, ie, its thickness substantially increased, as shown clearly by the arrows in Fig. 2. For this purpose, preferably a tube of the polymer or polymer network according to the invention is first prepared, which is then stretched from its initial state by about 1000%, so that this at least 800% elongation by the incipient crystallization, ie the formation of metastable crystals, is stabilized. In order to prevent a reduction of the tube diameter during stretching, a guide pin is preferably inserted into the tube. From the tube then short pieces are cut and applied as an O-ring 10 either on the tube 12 or inserted into the sleeve 14, as shown in Fig. 1. The fat The swellable O-ring 10 is to be adjusted so that the tube 12 and the sleeve 14 are easily plugged into each other. After joining tube 12 and sleeve 14, the pipe system already has a basic tightness. The final swelling of the O-ring 10 shown in Figure 2, in the form of a thickness increase and a width reduction, is initiated either by heating the sleeve 14, for example by means of a hot air dryer, or by purging the pipe system with hot water or other liquids. It is advantageously possible to achieve thickness increases of more than 300% of the O-ring.

3 and 4 show a second embodiment of a swellable O-ring 10, wherein the tube 12 on its outer surface has a toothing or a thread 24, by means of which the strength of the pipe joint can be increased by the swellable O-ring. Ring 10 spreads when swelling within the toothing.

Fig. 5, Fig. 6 and Fig. 7 show a swellable dowel 16 made of the polymer or polymer network according to the invention, this swellable dowel 16 is particularly suitable for critical substrates or critical walls. In order to dowel in porous walls or holes not precisely drilled, plaster or similar products is usually used to ensure a firm anchorage of the dowel and thus the screw in the wall can. The disadvantage here is the relatively high expenditure of time since it must be waited before screwing the screw on the curing of the plaster. This disadvantage can be solved by the use of a hybrid dowel 16. This hybrid dowel has a standard dowel 18 and a swellable material 20 surrounding the standard dowel, wherein the swellable material 20 is made from the polymer or polymer network of the present invention. The hybrid dowel 16 is inserted into a bore 22 as shown in FIG. 6 and then heated to initiate swelling of the swellable material 20, as shown in FIG. The heating can already be done by screwing in the screw 22 in the dowel 18 by generating frictional heat or additionally by means of a Heißluftföns respectively.

Fig. 8 shows a possible embodiment for a temperature threshold detector 26 made of the inventive polymer or polymer network. The temperature threshold detector 26 is preferably in the form of a check card format and has a plurality of adjacently arranged strain-induced crystallized strips 28 of a material of a polymer or polymer network according to the invention, each strip 28 having a different trigger temperature. The strips 28 are each introduced between two plastic films in such a way that they are preferably fastened to one side and contract when the respective triggering temperature is exceeded in such a way that a window 30 which has previously been hidden by the strip 28 is opened and the triggering temperature 32 printed thereunder becomes visible , This can be made visible, which temperature has been exceeded. In this example, a temperature of - 1 5 ⁰ C was exceeded. Because each strip 28 has a different trigger temperature, exceeded temperatures can be displayed in a wide range.

Fig. 9 shows a schematic representation of the various states of the polymer network 32 according to the invention. The polymer or polymer network 32 is preferably made of a rubber-elastic material which crystallizes under strain and remains in this stretched, transient state 34 until full relaxation, ie, relaxation, results from an external stimulus complete return of the polymer network 32 to its unstretched initial state 36 is initiated. In the relaxation of the stretched polymer network 32 by triggering an external stimulus, a shrinkage ratio of the polymer network of up to 10: 1, indicated by the arrows 38, and a threshold ratio of the polymer network of up to 1: 3, indicated by the arrow 40, can be achieved , The polymer or polymer network according to the invention is therefore distinguished by particularly good molding properties. Further, in the polymer or polymer network of the present invention, it is possible to physically physically vary It is possible to use the polymer or polymer network according to the invention as a cold storage.

example

A polymer or polymer network of a 1,4-cis polyisoprene (natural rubber) is used. To generate the specific example network, a natural rubber SMR10 (standard Malaysian Rubber) with 0.02 [wt.]% Sulfur, 0.02 [wt.]% Accelerator CBS (N-cyclohexyl-2benzothiazole sulfenamides CAS # 95-330 ) and 0.8% antioxidant 6PPT (N- (l, 3dimethylbutyl) -N-phenyl-p-phenyldiamine CAS # 793-24-8) using a heatable double roller roller at 100 ⁰ C mastifiziert for 15 min and then at 140 ⁰ C using a hot press for 15 min to 3 mm thick plates vulcanized.

This polymer or polymer network is transferred from the initial state to a stretched state at a strain rate of 1000% / s. This is done at an ambient temperature of 23 ^° C. The stretched polymer or polymer network is then held in the stretched state for a holding time of 1 minute. Subsequently, a relaxation of the polymer network takes place with a relaxation rate of 100% / s of the held, stretched state in a relaxed state. In the relaxed state, the polymer or polymer network still has an elongation of 800% compared to the initial state. The thus-processed polymer or polymer network of 1,4-cis-polyisoprene has a trigger temperature of 28 ⁰ C and an endothermic heat of reaction at break of the crystals and the complete return to the original state of about 9 J / g.

Claims

PATENT APPLICATIONS

1. A polymer or polymer network in a stretched, dimensionally stable state, having a trigger point adjustable as a function of strain rate and / or ambient temperature, the trigger point being set within a range below the theoretical melting point temperature and above the theoretical melting point temperature

Ambient temperature, wherein the polymer or polymer network remains in a taut, dimensionally stable condition, whereby triggering of the trigger ruptures the crystals of the polymer or polymer network, thereby relaxing the taut polymer or polymer network and rendering the polymer or polymer network dimensionally stable upon relaxation; stretched state in the unstretched state cools below the ambient temperature.

2. polymer or polymer network according to claim 1, wherein the elongation of the polymer or polymer network in the tense, dimensionally stable state> 30% to <95%, preferably> 40% to <90%, more preferably> 45% to <85%, even further preferably> 50% to <80%, more preferably> 55% to <75% and more preferably> 60% to <70% of the maximum elongation at break of the polymer or of the polymer network.

3. polymer or polymer network according to claim 1 or 2, wherein the endothermic

Congestion as a result of the rupture of the crystals and the relaxation in the

original state> 0.1 J / g to <100 J / g, preferably> 1 J / g to <90 J / g, more preferably> 5 J / g to <70 J / g, and particularly preferably> 7 J / g to <50 J / g.

4. Polymer or polymer network according to any preceding claim, wherein the of forming rupturable crystals suitable polymers or polymer networks a crystallization rate of> 10 ^"7% / s to <100% / s, preferably of>^{10" 5%} / s to < 70% / s, and in particular from> 10 ^"4 % / s to <50% / s.

Polymer or polymer network according to one of the preceding claims, wherein the rupturable crystals are formed by stretching the polymer or the polymer network, and the polymer or polymer network in the stretched state with a holding time of> 0 s to <1 d, preferably> 0, 05 s to <12 h, more preferably> 0.1 s to <6 h, more preferably> 0.5 s to <3 h, further preferably> 1 s to <1 h, further preferably> 2 s to <50 min , furthermore preferably> 5 s to <40 min, more preferably> 10 s to <30 min, further preferably> 15 s to <20 min, further preferably> 20 s to <10 min, further preferably> 30 s to <5 min , furthermore preferably> 40 s to <2 min, more preferably> 50 s to <1 min., Is maintained.

6. Polymer or polymer network according to one of the preceding claims, wherein the temperature range of the physically variable trigger points, preferably by the content of additive (s) which are suitable for lowering or increasing the glass transition temperature and / or lowering or increasing the crystallization rate of the polymer or polymer network, displaceable and / or expandable and / or reducible.

7. polymer or polymer network according to one of the preceding claims, wherein the temperature range of the physically variable trigger points by means of the strain rate used in the expansion and / or by means of the prevailing at the strain ambient temperature is adjustable.

Polymer or polymer network according to one of the preceding claims, wherein in the polymer or polymer network with rupturable crystals whose transparency in the wavelength range of ldm to lnm at room temperature over the polymer or polymer network without rupturable crystals by a factor of 1000 to 1.12, preferred reduced by a factor of 100 to 1.5, more preferably by a factor of 10 to 1.

9. polymer or polymer network according to one of the preceding claims, wherein the polymer or polymer network after stretching in the tense, dimensionally stable, crystallized state a degree of crystallinity of> 1% to <80%, preferably from> 5% to <50%, more preferably from > 10% to <30%.

10. polymer or polymer network according to one of the preceding claims, wherein> 10% to

<100%, preferably> 15% to <95%, more preferably> 20% to <80%, even more preferably> 30% to <70%, and particularly preferably> 40% to <60%, of all crystals of the polymer or of the polymer network are oriented in the stretched, dimensionally stable, state in the stretching direction of the polymer or of the polymer network.

11. Polymer or polymer network according to one of the preceding claims, wherein the crystals present in the stressed, dimensionally stable, state have a proportion of> 5% to

<100%, preferably> 20% to <90%, more preferably> 30% to <80%, even more preferably> 40% to <70%, and particularly preferably> 50% to <60%, lamellar crystals are, and preferably the lamellar crystals have a lamella thickness of> 1 nm to <50 nm, preferably from> 3 nm to <30 nm, particularly preferably from> 5 nm to <25 nm.

A polymer or polymer network according to any one of the preceding claims wherein the polymer or polymer network is selected from the group consisting of: configurationally crystallizable polymers, isotactic polymers, syndiotactic polymers, natural rubber, polyisoprene, polyethylene terephthalate, polycarbonate, isotactic polystyrene and / or a copolymer is formed.

13. A method for adjusting a trigger point of rupturable crystals within a polymer or polymer network according to any one of claims 1 to 12, comprising the following steps:

A) providing a polymer or polymer network;

B) transferring the polymer or polymer network from an unstretched initial state to a stretched state, preferably by means of an expansion rate of the polymer network of> 10 ^{~ 7} % / s to <10 ⁷ % / s;

C) maintaining the polymer or polymer network in the stretched state, preferably with a hold time of> 0 s to <1 d, preferably> 0.05 s to <12 h, more preferably> 0.1 s to <6 h, even more preferred > 0.5 s to <3 h, more preferably> 1 s to ≦ 1 h, further preferably> 2 s to <50 min, further preferably> 5 s to <40 min, further preferably> 10 s to <30 min, furthermore preferably> 15 s to <20 min, more preferably> 20 s to <10 min, further preferably> 30 s to <5 min, further preferably> 40 s to <2 min, further preferably> 50 s to <1 min;

D) transferring the polymer or polymer network from the stretched state to a relaxed state, preferably at a relaxation rate of> 10 ⁷ % / s to <10 ⁷ % / s, wherein in the relaxed state the polymer or polymer network has crystals in a shape stabilizing state,

14. Use of a polymer and / or polymer network according to one of claims 1 to 12 in and / or in:

- agents with dimensional change properties,

- swellable material for use as a sealant;

- temperature threshold detector;

- shrink tubing;

- cold storage;

- heat pump;

- actor;

- actuator-sensor combination;

a solvent detector;

- artificial muscle;

- stent.

15. An article comprising a polymer and / or polymer network according to any one of claims 1 to 12.