CN114437352A - Intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material and preparation and application thereof - Google Patents
Intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material and preparation and application thereof Download PDFInfo
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- 239000000463 material Substances 0.000 title claims abstract description 44
- 239000004997 Liquid crystal elastomers (LCEs) Substances 0.000 title claims abstract description 30
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 239000004973 liquid crystal related substance Substances 0.000 claims abstract description 37
- 239000000178 monomer Substances 0.000 claims abstract description 21
- 239000004970 Chain extender Substances 0.000 claims description 14
- 239000003431 cross linking reagent Substances 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 12
- 238000002156 mixing Methods 0.000 claims description 10
- 238000001816 cooling Methods 0.000 claims description 9
- 238000001704 evaporation Methods 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 8
- 229920001971 elastomer Polymers 0.000 claims description 5
- 239000000806 elastomer Substances 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 4
- 238000006116 polymerization reaction Methods 0.000 claims description 4
- 238000005286 illumination Methods 0.000 claims description 3
- 239000012949 free radical photoinitiator Substances 0.000 claims description 2
- 230000017525 heat dissipation Effects 0.000 claims description 2
- 239000003960 organic solvent Substances 0.000 claims description 2
- 239000002904 solvent Substances 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 229920000106 Liquid crystal polymer Polymers 0.000 abstract description 8
- 239000004977 Liquid-crystal polymers (LCPs) Substances 0.000 abstract description 8
- LSDPWZHWYPCBBB-UHFFFAOYSA-N Methanethiol Chemical compound SC LSDPWZHWYPCBBB-UHFFFAOYSA-N 0.000 abstract description 3
- 238000011031 large-scale manufacturing process Methods 0.000 abstract description 3
- 238000003490 calendering Methods 0.000 abstract description 2
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 48
- 239000012528 membrane Substances 0.000 description 12
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G75/00—Macromolecular compounds obtained by reactions forming a linkage containing sulfur with or without nitrogen, oxygen, or carbon in the main chain of the macromolecule
- C08G75/02—Polythioethers
- C08G75/04—Polythioethers from mercapto compounds or metallic derivatives thereof
- C08G75/045—Polythioethers from mercapto compounds or metallic derivatives thereof from mercapto compounds and unsaturated compounds
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
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- C08J5/18—Manufacture of films or sheets
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2381/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing sulfur with or without nitrogen, oxygen, or carbon only; Polysulfones; Derivatives of such polymers
- C08J2381/02—Polythioethers; Polythioether-ethers
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Abstract
The invention discloses an intrinsic high-flexibility high-thermal-conductivity liquid crystal elastomer material which has a structural formula shown as a formula I, wherein o is 0-10, p is 1-10, q is 1-10, and n is more than or equal to 1; r is selected from H, Cl, Br, F and CH3，OCH3And COOCH3One kind of (1). According to the invention, double-bond-terminated prepolymer is prepared by click chemistry reaction of double-terminal double-bond liquid crystal monomer and mercaptan, further calendering and uniaxial stretching are carried out to keep liquid crystal orientation to form an ordered structure, phonon scattering free path is improved, the prepared intrinsic liquid crystal elastomer material has high heat conduction (0.3-1.5W/m K) in the orientation direction and high elongation at break (more than or equal to 100%), the problems of complex preparation, difficulty in large-scale production and poor flexibility of the existing intrinsic heat conduction liquid crystal polymer thermal interface material are solved, and the intrinsic heat conduction liquid crystal elastomer material has wide application as the thermal interface materialAnd 4, application prospect.
Description
Technical Field
The invention belongs to the technical field of high-thermal-conductivity high polymer materials, and particularly relates to an intrinsic high-flexibility high-thermal-conductivity liquid crystal elastomer material, and preparation and application thereof.
Background
With the development of large-sized high-power chips, the working stability and the service life of the chips are seriously influenced by heat accumulation, and the key problem is to develop a thermal interface material with high heat conduction in the heat conduction direction. The polymer has the advantages of light weight, easy processing and forming, good mechanical property, low conductivity and low cost, is one of the main categories of widely used heat management materials, but compared with the traditional metal or ceramic materials, the polymer has low thermal conductivity coefficient (0.1-0.2W K) due to the irregular winding of polymer molecular chains, low crystallinity and the scattering effect of molecular chain vibration on phonons-1m-1) And is the biggest bottleneck limiting its application in thermal management materials. In order to improve the thermal conductivity of polymer materials, a common method is to dope inorganic fillers with high thermal conductivity, but the mechanical properties of the materials are reduced. Compared with filled high-molecular composite materials, pure high molecules with certain heat conductivity are obtained by changing the intrinsic structure of the high molecules and are called intrinsic heat-conducting high-molecular materials, molecular dynamics simulation and experimental research show that a single polymer chain serving as a low-dimensional material theoretically has quite high heat conductivity coefficient, and an effective method for essentially improving the intrinsic heat conductivity of the polymer is to improve the orientation of the polymer chain and increase the order of the polymer and the number of orientation regions. As is known to all, liquid crystal polymers show spontaneous local orientation and excellent anisotropy, so that the liquid crystal polymers are expected to be ideal intrinsic high-thermal conductivity materials, and most researches need to adopt methods such as mechanical friction, electric fields or magnetic fields to orient liquid crystal monomers and then polymerize the liquid crystal monomers to prepare macroscopic ordered structures.
The document Polym.Commun.1991,32,285 uses a twin-screw extrusion and injection molding method to prepare a polyurethane liquid crystal polymer into parallel oriented films and fibers, and the thermal conductivity along the long axis direction of the fibers is measured to be 1.85W/m K.
The document Adv.Mater.1993,5,107 reports that the surface orientation of acrylate liquid crystal molecules is carried out by mechanical friction, and then a liquid crystal polymer film is prepared by ultraviolet polymerization, and the horizontal direction thermal conductivity is up to 5.2W/m K.
The document J.Polym.SCI.pol.Phys.2003,41,1739 vertically aligns amorphous liquid crystal epoxy resin by magnetic field, and thermally cures and crosslinks, and its thermal conductivity along the direction of magnetic field is 0.89W/m K as measured by laser flash method.
Document chem.Commun.2016,52,4313 reports that acrylate liquid crystal monomers synthesized by electric field alignment are photocured to form liquid crystal films after being aligned by electric field, and the thermal conductivity along the direction of the electric field is up to 2.44W/m K.
Thermal interface materials require not only high thermal conductivity, but also high tensile properties during use to alleviate the warpage failure problem caused by stress concentrations resulting from mismatch of thermal expansion coefficients of the chip, the vapor chamber, and the heat sink. The thermal interface material prepared by the method can not meet the requirements of high heat conduction and high flexibility, the preparation conditions are complex, the cost is high, and the mechanical properties of the high heat conduction liquid crystal polymer are not researched.
Disclosure of Invention
The invention provides an intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material and preparation and application thereof, and aims to solve the problems that the intrinsic thermal-conductivity liquid crystal polymer thermal interface material is complex in preparation, not beneficial to large-scale production and poor in flexibility.
The invention provides an intrinsic high-flexibility and high-thermal conductivity liquid crystal elastomer material, which has a structural formula shown as a formula I,
wherein o is 0-10, p is 1-10, q is 1-10, and n is not less than 1;
r is selected from H, Cl, Br, F and CH3，OCH3And COOCH3One kind of (1).
The invention provides a preparation method of an intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material, which comprises the following steps:
(1) dissolving a double-end double-bond liquid crystal monomer shown in a formula II, a chain extender shown in a formula III and a photoinitiator in an organic solvent, and reacting under room temperature ultraviolet illumination to obtain a prepolymer solution;
wherein o is 0-10, p is 1-10, and q is 1-10;
r is selected from H, Cl, Br, F and CH3，OCH3And COOCH3One of (1);
(2) adding a cross-linking agent and a photoinitiator into the prepolymer solution obtained in the step (1), uniformly mixing, evaporating to remove the solvent, drying in vacuum, then placing on a centrifugal film, heating to be completely clear, cooling to a temperature below 20 ℃ to form an ordered liquid crystal phase, placing on a calender, carrying out ultraviolet irradiation click polymerization after uniaxial stretching orientation, and taking out the film to obtain the intrinsic high-flexibility and high-thermal conductivity liquid crystal elastomer material.
Further, calculated by the amount of substances, the double-end double-bond liquid crystal monomer in the step (1) is 1-10 parts, the chain extender is 0-9 parts, and the photoinitiator is 0.01 part.
Further, the mass ratio of the double-end double-bond liquid crystal monomer to the chain extender in the step (1) is n: (n-1).
Further, the cross-linking agent is selected from one of the following compounds,
further, the photoinitiator is a free radical photoinitiator;
preferably, the photoinitiator is selected from one of the following compounds,
further, the heating temperature in the step (2) is 25-120 ℃.
The third aspect of the invention provides an application of the intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material or the intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material prepared by the preparation method in heat dissipation of electronic devices.
The invention provides the application of the intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material or the intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material prepared by the preparation method as a thermal interface material.
The invention has the beneficial effects that:
according to the intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material, a double-bond-terminated prepolymer is prepared by click chemical addition of commercial liquid crystal monomers with double bonds at two ends and mercaptan, the isotropic temperature of the liquid crystal monomers can be adjusted to be suitable for the application range of a thermal interface material, the tensile property of the material can be effectively improved by introducing a flexible chain segment, a liquid crystal ordered structure is formed at a certain temperature by adding a polyfunctional mercaptan crosslinking agent and a photoinitiator, the orientation is realized by a calendering method, the liquid crystal orientation is locked by further click chemical crosslinking through illumination, a structure with a certain orientation is formed, and the phonon scattering free path is improved. The intrinsic liquid crystal elastomer material has high thermal conductivity (0.3-1.5W/m K) in the orientation direction and high elongation at break (more than or equal to 100%), solves the problems that the existing intrinsic thermal conductive liquid crystal polymer thermal interface material is complex in preparation, not beneficial to large-scale production and poor in flexibility, and has wide application prospects as a thermal interface material.
Drawings
FIG. 1 shows the mechanical orientation and polymerization of an intrinsically highly flexible, highly thermally conductive liquid crystalline elastomer.
Detailed Description
In order that the invention may be more clearly understood, it will now be further described with reference to the following examples and the accompanying drawings. The examples are for illustration only and do not limit the invention in any way. In the examples, each raw reagent material is commercially available, and the experimental method not specifying the specific conditions is a conventional method and a conventional condition well known in the art, or a condition recommended by an instrument manufacturer.
1. The liquid crystal elastomer of the invention has the following specific heat capacity test, density test, thermal diffusion coefficient test and thermal conductivity coefficient calculation:
1) specific heat capacity test: the specific heat capacity of the sample is calculated by testing the DSC curves of the blank sample, the sapphire and the sample by using a sapphire method in a differential thermal scanner of the relaxation-resistant company. Spreading 5mg of sample in a crucible, heating from-20 ℃ to 200 ℃ at the speed of 10 ℃/min to obtain a DSC curve, and calculating the specific heat capacity parameter of the sample by using the formula (1).
Wherein m is1Is the mass of sapphire, m2Is the mass of the sample, Y0Is the DSC value of the base line at temperature T, Y1Is the DSC value of sapphire at temperature T, Y2Is the DSC value of the sample at temperature T, C1Is the specific heat capacity of sapphire, C2Is the specific heat capacity of the sample.
2) And (3) testing the density: the density of the samples was measured using a true densitometer and the average was taken five times for each sample.
3) Testing thermal diffusion coefficient: the thermal diffusion coefficient of the film along the orientation direction and the direction vertical to the curve is tested by a laser scattering method, a sample is cut into a circle with the diameter of 25.4mm by a mould, the surface is sprayed with a layer of graphite for shading, the graphite is placed in an instrument and is impacted on the surface of the sample by laser pulse, an infrared detector detects the temperature change of the upper surface of the sample, the thermal diffusion coefficient is simulated and calculated by software, and the average value is obtained by measuring each sample for three times.
4) Calculation of thermal conductivity: thermal conductivity is specific heat capacity density thermal diffusivity.
2. Testing of elongation at break of liquid crystal elastomers
The test was carried out at room temperature using a universal stretcher (Shimadzu, Japan, model AG-X plus 10N-10 kN). The width and thickness of the thermal interface material tested were 20.0mm and 0.2mm, respectively. During testing, the initial clamping distance between the upper and lower chucks was fixed at 20mm, and the stretching rate was set at 10 mm/min.
3. The double-end double-bond liquid crystal monomer, the chain extender, the photoinitiator and the cross-linking agent in the embodiment of the invention are shown in the following table 1:
TABLE 1
Example 1
Dissolving 5.29g (10mmol) of double-end double-bond liquid crystal monomer, 0.97g (9mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, irradiating for 2 minutes by using 365nm ultraviolet light after complete dissolution, stirring for 1 hour at room temperature, adding 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator, fully mixing, evaporating dichloromethane, drying for 1 day in vacuum, placing the mixture on a centrifugal membrane, heating at 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet light crosslinking for 2 minutes, and taking out the membrane to obtain the oriented liquid crystal elastomer. The thermal conductivity of the film in the orientation direction is 1.2W/mK, the thermal conductivity of the film in the machine direction is 0.5W/mK, and the elongation at break is 600 percent.
Example 2
Dissolving 2.22g (5mmol) of double-end double-bond liquid crystal monomer, 1.52g (4mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, irradiating for 2 minutes by using 365nm ultraviolet light after complete dissolution, stirring for 1 hour at room temperature, adding 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator, fully mixing, evaporating dichloromethane, drying for 1 day in vacuum, placing the mixture on a centrifugal membrane, heating at 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet light crosslinking for 2 minutes, and taking out the membrane to obtain the oriented liquid crystal elastomer. The film has a thermal conductivity of 1.0W/mK in the orientation direction, a thermal conductivity of 0.4W/mK in the machine direction and an elongation at break of 500%.
Example 3
Dissolving 5.29g (10mmol) of double-end double-bond liquid crystal monomer, 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, fully mixing, evaporating dichloromethane, vacuum drying for 1 day, placing the mixture on a centrifugal film, heating to 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet crosslinking for 2 minutes, and taking out the film to obtain the oriented liquid crystal elastomer. The film has a thermal conductivity of 0.8W/mK in the orientation direction, a thermal conductivity of 0.3W/mK in the machine direction and an elongation at break of 100%.
Example 4
6.96g (10mmol) of double-end double-bond liquid crystal monomer, 0.97g (9mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator are dissolved in 10mL of dichloromethane, after complete dissolution, the mixture is irradiated by 365nm ultraviolet light for 2 minutes, stirred at room temperature for 1 hour, then 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator are added, after full mixing, the dichloromethane is evaporated, vacuum drying is carried out for 1 day, the mixture is placed on a centrifugal film to be heated at 100 ℃, then cooled to 70 ℃ to form an ordered liquid crystal phase, placed on a calender at 70 ℃, after uniaxial stretching orientation, ultraviolet light at 365nm is used for crosslinking for 2 minutes, and the film is taken out, thus obtaining the oriented liquid crystal elastomer. The film has a thermal conductivity of 1.0W/mK in the orientation direction, a thermal conductivity of 0.4W/mK in the machine direction and an elongation at break of 600%.
Example 5
Dissolving 5.14g (10mmol) of double-end double-bond liquid crystal monomer, 0.97g (9mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, irradiating for 2 minutes by using 365nm ultraviolet light after complete dissolution, stirring for 1 hour at room temperature, adding 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator, fully mixing, evaporating dichloromethane, drying for 1 day in vacuum, placing the mixture on a centrifugal membrane, heating at 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet light crosslinking for 2 minutes, and taking out the membrane to obtain the oriented liquid crystal elastomer. The film has the thermal conductivity of 1.5W/mK in the orientation direction, the thermal conductivity of 0.5W/mK in the longitudinal direction and the elongation at break of 600 percent.
Example 6
Dissolving 5.32g (10mmol) of double-end double-bond liquid crystal monomer, 0.97g (9mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, irradiating for 2 minutes by using 365nm ultraviolet light after complete dissolution, stirring for 1 hour at room temperature, adding 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator, fully mixing, evaporating dichloromethane, drying for 1 day in vacuum, placing the mixture on a centrifugal membrane, heating at 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet light crosslinking for 2 minutes, and taking out the membrane to obtain the oriented liquid crystal elastomer. The thermal conductivity of the film in the orientation direction is 1.3W/mK, the thermal conductivity of the film in the machine direction is 0.5W/mK, and the elongation at break is 600 percent.
Example 7
Dissolving 5.45g (10mmol) of double-end double-bond liquid crystal monomer, 0.97g (9mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, irradiating for 2 minutes by using 365nm ultraviolet light after complete dissolution, stirring for 1 hour at room temperature, adding 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator, fully mixing, evaporating dichloromethane, drying for 1 day in vacuum, placing the mixture on a centrifugal membrane, heating at 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet light crosslinking for 2 minutes, and taking out the membrane to obtain the oriented liquid crystal elastomer. The thermal conductivity of the film in the orientation direction is 1.3W/mK, the thermal conductivity of the film in the machine direction is 0.5W/mK, and the elongation at break is 600 percent.
Example 8
Dissolving 5.73g (10mmol) of double-end double-bond liquid crystal monomer, 0.97g (9mmol) of chain extender and 0.026g (0.01mmol) of photoinitiator in 10mL of dichloromethane, irradiating for 2 minutes by using 365nm ultraviolet light after complete dissolution, stirring for 1 hour at room temperature, adding 0.244g (0.5mmol) of cross-linking agent and 0.026g (0.01mmol) of photoinitiator, fully mixing, evaporating dichloromethane, drying for 1 day in vacuum, placing the mixture on a centrifugal membrane, heating at 120 ℃, cooling to 100 ℃ to form an ordered liquid crystal phase, placing on a calender at 100 ℃, carrying out uniaxial stretching orientation, carrying out 365nm ultraviolet light crosslinking for 2 minutes, and taking out the membrane to obtain the oriented liquid crystal elastomer. The thermal conductivity of the film in the orientation direction is 1.3W/mK, the thermal conductivity of the film in the machine direction is 0.5W/mK, and the elongation at break is 600 percent.
The results of testing the thermal conductivity and elongation at break of the thermal interface materials provided in examples 1-5 according to the above methods are shown in table 2:
TABLE 2
The invention is described in the above embodiments by the preparation process of the intrinsic highly flexible and highly heat conductive liquid crystal elastomer provided by the invention, but the invention is not limited to the above process steps, i.e. the invention is not meant to be implemented only by relying on the above process steps. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.
Claims (9)
1. An intrinsic high-flexibility high-thermal-conductivity liquid crystal elastomer material is characterized by having a structural formula shown as a formula I,
wherein o is 0-10, p is 1-10, q is 1-10, and n is not less than 1;
r is selected from H, Cl, Br, F and CH3，OCH3And COOCH3One kind of (1).
2. A preparation method of an intrinsic high-flexibility and high-thermal-conductivity liquid crystal elastomer material is characterized by comprising the following steps:
(1) dissolving a double-end double-bond liquid crystal monomer shown in a formula II, a chain extender shown in a formula III and a photoinitiator in an organic solvent, and reacting under room temperature ultraviolet illumination to obtain a prepolymer solution;
wherein o is 0-10, p is 1-10, and q is 1-10;
r is selected from H, Cl, Br, F and CH3，OCH3And COOCH3One of (1);
(2) adding a cross-linking agent and a photoinitiator into the prepolymer solution obtained in the step (1), uniformly mixing, evaporating to remove the solvent, drying in vacuum, then placing on a centrifugal film, heating to be completely clear, cooling to a temperature below 20 ℃ to form an ordered liquid crystal phase, placing on a calender, carrying out ultraviolet irradiation click polymerization after uniaxial stretching orientation, and taking out the film to obtain the intrinsic high-flexibility and high-thermal conductivity liquid crystal elastomer material.
3. The preparation method according to claim 2, wherein the amount of the double-end double-bond liquid crystal monomer in the step (1) is 1-10 parts, the amount of the chain extender is 0-9 parts, and the amount of the photoinitiator is 0.01 part.
4. The production method according to claim 3, wherein the mass ratio of the double-terminal double-bond liquid crystal monomer and the chain extender in the step (1) is n: (n-1).
5. The method according to claim 2, wherein the crosslinking agent is one selected from the group consisting of compounds represented by,
6. the method of claim 2, wherein the photoinitiator is a free radical photoinitiator;
preferably, the photoinitiator is selected from one of the following compounds,
7. the method according to claim 2, wherein the heating temperature in the step (2) is 25 to 120 ℃.
8. Use of the intrinsic highly flexible, highly thermally conductive liquid crystalline elastomer material according to claim 1 or the intrinsic highly flexible, highly thermally conductive liquid crystalline elastomer material prepared by the preparation method according to any one of claims 2 to 7 for heat dissipation in electronic devices.
9. Use of the intrinsic highly flexible, highly thermally conductive liquid crystalline elastomer material according to claim 1 or the intrinsic highly flexible, highly thermally conductive liquid crystalline elastomer material prepared by the preparation method according to any one of claims 2 to 7 as a thermal interface material.
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| WO2008077261A1 (en) * | 2006-12-22 | 2008-07-03 | Rolic Ag | Patternable liquid crystal polymer comprising thio-ether units |
| CN106883863A (en) * | 2017-03-23 | 2017-06-23 | 清华大学 | Liquid crystal elastic body driving element and preparation method thereof, and liquid crystal elastic body application |
| CN110054718A (en) * | 2018-01-19 | 2019-07-26 | 清华大学 | Composition, multidomain liquid crystal elastomer, single domain liquid crystal elastomer and its preparation, processing and welding method |
| CN113980273A (en) * | 2021-10-21 | 2022-01-28 | 清华大学 | Liquid crystal elastomer driver and preparation method thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008077261A1 (en) * | 2006-12-22 | 2008-07-03 | Rolic Ag | Patternable liquid crystal polymer comprising thio-ether units |
| CN106883863A (en) * | 2017-03-23 | 2017-06-23 | 清华大学 | Liquid crystal elastic body driving element and preparation method thereof, and liquid crystal elastic body application |
| CN110054718A (en) * | 2018-01-19 | 2019-07-26 | 清华大学 | Composition, multidomain liquid crystal elastomer, single domain liquid crystal elastomer and its preparation, processing and welding method |
| CN113980273A (en) * | 2021-10-21 | 2022-01-28 | 清华大学 | Liquid crystal elastomer driver and preparation method thereof |
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