Method for preparing synergistic liquid crystal / high-conductivity silicone rubber composite material

Abstract

The present invention relates to the technical field of the preparation of synergistic liquid crystal / high-conductivity silicone rubber composite materials. Disclosed is a method for preparing a synergistic liquid crystal / high-conductivity silicone rubber composite material. The method comprises the following steps: first, synthesizing BP6; then synthesizing flexible liquid crystal polyurethane; finally, mixing VMQ and FLCPU in a mechanical blending mode, and then sequentially adding conductive carbon black and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane thereto, so as to obtain an FLCPU-modified VMQ / CCB rubber compound; and subjecting the rubber compound to hot press molding on a plate vulcanizing machine to obtain a finished product, subjecting the finished product to material detection before and after modification, and extracting data. In the method for preparing the synergistic liquid crystal / high-conductivity silicone rubber composite material, the dispersion of conductive carbon black in a rubber matrix can be improved on the basis of modification by means of a biphenyl type mesogenic unit structural material, and the conjugated structure of a mesogenic unit can also improve the transition capacity of electrons in response to the stimulus of temperature, thereby achieving a significant synergistic effect.

Description

Preparation method of liquid crystal synergistic high conductive silicone rubber composite material Technical Field

[0001] The present invention relates to the technical field of preparation of liquid crystal synergistic high-conductive silicone rubber composite materials, and in particular to a preparation method of liquid crystal synergistic high-conductive silicone rubber composite materials. Background Art

[0002] Conductive rubber composites are widely used in flexible sensing and electromagnetic shielding materials due to their softness, low cost, flexibility, and easy processing. Silicone rubber has good high and low temperature resistance, excellent processing and mechanical properties, and unique chemical stability, and is usually used in harsh environments. However, the conductivity of ordinary silicone rubber is poor, and its conductivity can be significantly improved by adding conductive fillers. Commonly used conductive fillers are divided into two types: metal conductive fillers (such as silver powder and copper powder) and carbon conductive fillers (such as conductive carbon black, graphene, and carbon nanotubes);

[0003] Most of the conductive silicone rubber currently sold on the market is made from acetylene carbon black, but its preparation process is relatively complicated, and the resistivity of the conductive rubber is still at a relatively high level and cannot be used for the development of efficient flexible electromagnetic shielding and temperature sensor devices.

[0004] Therefore, the present invention provides a method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material to solve the above-mentioned problems.

[0005] Summary of the Invention

[0006] Technical problems solved

[0007] In response to the shortcomings of the existing technology, the present invention provides a method for preparing a liquid crystal synergistic high-conductive silicone rubber composite material. Based on the modification of the biphenyl-type liquid crystal unit structural material, the dispersion of conductive carbon black in the rubber matrix can be improved. At the same time, the conjugated structure of the liquid crystal unit can enhance the transition ability of electrons under temperature stimulation, achieving significant synergistic effects and other advantages, thereby solving the problem that the resistivity of conductive rubber is still at a relatively high level and cannot be used for the development of efficient flexible electromagnetic shielding and temperature sensor devices.

[0008] Technical Solution

[0009] To achieve the above-mentioned purpose of improving the dispersion of conductive carbon black in the rubber matrix, and at the same time, the conjugated structure of the liquid crystal unit can enhance the transition ability of electrons under temperature stimulation, thereby achieving a significant synergistic effect, the present invention provides the following technical solution: A method for preparing a liquid crystal synergistic high-conductive silicone rubber composite material, comprising the following steps:

[0010] Step 1:

[0011] First, the intermediate 4,4′-bis(β-hydroxyhexyloxy)biphenyl (BP6) was synthesized by dissolving 0.33 g of dihydroxybiphenyl and 6-chloro-1-hexanol in 50 ml of ethanol at a molar ratio of 1:2. The mixture was ultrasonically dispersed for 1 minute and transferred to a three-necked flask. Sodium hydroxide solution was added dropwise with stirring. After filtration, the mixture was washed twice with deionized water and dried to obtain the intermediate BP6.

[0012] Step 2:

[0013] Then, the synthesis of flexible liquid crystal polyurethane (FLCPU) was carried out based on step 1:

[0014] BP6 recrystallization: BP6 was dissolved in a mixed solvent, heated to boil for 1-2 minutes, cooled to room temperature to complete the first recrystallization, the supernatant was removed, the above mixed solvent was added again, heated to boil for 1-2 minutes, cooled to room temperature to complete the second crystallization, and dried to obtain the second recrystallized BP6 intermediate;

[0015] Toluene diisocyanate (TDI) and BP6 were dissolved in an appropriate amount of DMF at a ratio of (1.01-1.05):1, ultrasonically dispersed for 5-10 minutes, transferred to a three-necked flask, stirred, and 1-4% dibutyltin dilaurate was added dropwise. The mixture was reacted at 90-100°C for 20-28 hours. After cooling, the sample was filtered to obtain a sample, which was then rinsed with DMF 2-4 times, washed with deionized water 1-2 times, and dried to obtain a FLCPU sample.

[0016] Step 3:

[0017] VMQ and FLCPU are mixed by mechanical blending, and then conductive carbon black and dipentadienyl vulcanizing agent are added in sequence. After 20-25 minutes, FLCPU modified VMQ / CCB rubber compound is obtained. The rubber compound is hot-pressed on a flat vulcanizing press to obtain a finished product.

[0018] Step 4: Conduct material testing on the finished product of step 3 before and after modification and extract data.

[0019] Preferably, in the step 1, 40 ml of sodium hydroxide solution is added dropwise with stirring, and then the temperature is maintained at 90-100 ° C and the reaction is continued with stirring for 8-10 hours. The rigid structural unit of the intermediate BP6 in the step 1 is one or more of a benzene ring, an alicyclic ring or a heterocyclic ring. Intermediates with different rigid core compositions can also achieve the expected effect of this experiment.

[0020] Preferably, the specification of the sodium hydroxide solution is 2-2.5 mol / L.

[0021] Preferably, when BP6 is recrystallized in step 2, the mixed solvent is prepared by mixing 90 ml of ethanol and 30 ml of NN dimethylformamide (DMF); before obtaining the sample, a small amount of deionized water is required for end-capping treatment for 2-3 hours.

[0022] Preferably, the diisocyanate in step 2 is any one of toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI).

[0023] Preferably, the hot pressing molding working conditions of the flat plate vulcanizer in step 3 are 170-175° C., 5-10 min, and 13-15 MPa.

[0024] Preferably, the mechanical blending method in step 3 includes any one or more of open mixing, internal mixing and extrusion, and the modified carbon black cannot be added to the rubber after the FLCPU liquid phase modified carbon black synthesized in the early stage is used;

[0025] The amount of the modifier FLCPU in the silicone rubber conductive carbon black system is controlled at 3-5%. The order of adding materials in step 3 must be to blend VMQ and FLCPU first, and then add conductive carbon black and other additives in sequence to ensure that the modification effect is achieved.

[0026] Preferably, the types of detection in step 4 include DSC detection, mechanical detection, scanning electron microscopy analysis and volume resistivity detection. Beneficial effects

[0027] Compared with the prior art, the present invention provides a method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material, which has the following beneficial effects:

[0028] 1. The preparation method of this liquid crystal-synergistic highly conductive silicone rubber composite material is based on the modification of biphenyl-type liquid crystal unit structural materials, which can improve the dispersion of conductive carbon black in the rubber matrix. The intermediate BP6 can be replaced with a structure containing biphenyl or polycyclic aromatic hydrocarbons, which can also achieve the expected results of this experiment, expand the raw material selection of the product, and improve product production efficiency. The dosage of the modifier in the silicone rubber conductive carbon black system is determined, and it is clarified that the FLCPU used for modification must be introduced into the rubber composite matrix through mechanical mixing, internal mixing, extrusion, etc. It is not possible to use previously synthesized FLCPU to liquid-phase modify the carbon black and then add the modified carbon black to the rubber, highlighting the rigorous and accurate experimental preparation method.

[0029] 2. The preparation method of the liquid crystal synergistic high-conductive silicone rubber composite material can enhance the electron transition ability under temperature stimulation through the conjugated structure of the liquid crystal unit, thereby achieving a significant synergistic effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a schematic diagram of the synthesis of BP6 of the present invention;

[0031] FIG2 is a schematic diagram of the synthesis of the FLCPU of the present invention;

[0032] FIG3 is a schematic diagram of the DSC curves of BP6 and FLCPU synthesized in the present invention;

[0033] FIG4 is a schematic diagram of the mechanical stress-strain curve of the FLCPU modified VMQ / CCB vulcanizate of the present invention;

[0034] FIG5 is a cross-sectional SEM morphology of the VMQ / CCB composite material before and after FLCPU modification of the present invention;

[0035] FIG6 is a graph showing the change in volume resistivity of the VMQ / CCB composite material with temperature before and after FLCPU modification of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Example 1:

[0038] A method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material comprises the following steps:

[0039] Step 1:

[0040] First, the intermediate 4,4′-bis(β-hydroxyhexyloxy)biphenyl (BP6) was synthesized: 0.33 g of dihydroxybiphenyl was dissolved in 50 ml of ethanol with 6-chloro-1-hexanol in a molar ratio of 1:2, ultrasonically dispersed for 1 min, and transferred to a three-necked flask. Sodium hydroxide solution was added dropwise under stirring. After completion, the mixture was filtered and washed twice with deionized water. After drying, the intermediate BP6 was obtained. 40 ml of sodium hydroxide solution was added dropwise under stirring, and the temperature was maintained at 100°C and the reaction was stirred for 10 h. The specification of the sodium hydroxide solution was 2.5 mol / L. The rigid structural unit of the intermediate BP6 in step 1 was a heterocyclic ring. Intermediates with core compositions of different rigidities can also achieve the expected effect of this experiment.

[0041] Step 2:

[0042] Then, the synthesis of flexible liquid crystal polyurethane (FLCPU) was carried out based on step 1:

[0043] BP6 recrystallization: BP6 was dissolved in a mixed solvent, heated to boiling for 2 minutes, and cooled to room temperature to complete the primary recrystallization. The supernatant was removed, and the above mixed solvent was added again, heated to boiling for 2 minutes, and cooled to room temperature to complete the secondary crystallization. After drying, the secondary recrystallized BP6 intermediate was obtained. During the recrystallization of BP6, the mixed solvent was prepared by mixing 90 ml of ethanol and 30 ml of N-N dimethylformamide (DMF). Before obtaining the sample, it was required to be end-capped with a small amount of deionized water for 3 hours.

[0044] Toluene diisocyanate (TDI) and BP6 were dissolved in an appropriate amount of DMF at a ratio of 1.05:1, ultrasonically dispersed for 10 minutes, transferred to a three-necked flask, stirred, and 4% dibutyltin dilaurate was added dropwise. The mixture was reacted at 100°C for 28 hours. After cooling, the sample was filtered to obtain a sample, which was then rinsed with DMF four times, washed with deionized water twice, and dried to obtain a FLCPU sample. The diisocyanate was toluene diisocyanate (TDI).

[0045] Step 3:

[0046] VMQ and FLCPU were mixed by mechanical blending, and then conductive carbon black and dipentadienyl vulcanizing agent were added in sequence. After 25 minutes, a FLCPU-modified VMQ / CCB rubber compound was obtained. The rubber compound was hot-pressed on a flat-plate vulcanizer to obtain a finished product. The hot-pressing working conditions of the flat-plate vulcanizer were 175°C, 10 minutes, and a pressure of 15 MPa. The mechanical blending method was open mixing, and the amount of the modifier FLCPU in the silicone rubber conductive carbon black system was controlled at 5%.

[0047] The order of adding materials in step 3 must be to blend VMQ and FLCPU first, and then add conductive carbon black and other additives in sequence to ensure that the modification effect is achieved;

[0048] Step 4: Conduct material testing on the finished product of step 3 before and after modification and extract data;

[0049] The types of testing include DSC testing, mechanical testing, scanning electron microscopy analysis and volume resistivity testing.

[0050] Example 2:

[0051] A method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material comprises the following steps:

[0052] Step 1:

[0053] First, the intermediate 4,4′-bis(β-hydroxyhexyloxy)biphenyl (BP6) was synthesized: 0.33 g of dihydroxybiphenyl was dissolved in 50 ml of ethanol with 6-chloro-1-hexanol in a molar ratio of 1:2, ultrasonically dispersed for 1 minute, and transferred to a three-necked flask. Sodium hydroxide solution was added dropwise under stirring. After completion, the mixture was filtered and washed twice with deionized water. After drying, the intermediate BP6 was obtained. 40 ml of sodium hydroxide solution was added dropwise under stirring, and the temperature was maintained at 90°C and stirred for 8 hours. The specification of the sodium hydroxide solution was 2 mol / L. The rigid structural unit of the intermediate BP6 in step 1 was a benzene ring. Intermediates with core compositions of different rigidities can also achieve the expected effect of this experiment.

[0054] Step 2:

[0055] Then, the synthesis of flexible liquid crystal polyurethane (FLCPU) was carried out based on step 1:

[0056] BP6 recrystallization: BP6 was dissolved in a mixed solvent, heated to boiling for 1 min, and cooled to room temperature to complete the primary recrystallization. The supernatant was removed, and the above mixed solvent was added again, heated to boiling for 1 min, and cooled to room temperature to complete the secondary crystallization. After drying, the secondary recrystallized BP6 intermediate was obtained. During the recrystallization of BP6, the mixed solvent was prepared by mixing 90 ml of ethanol and 30 ml of N-N dimethylformamide (DMF). Before obtaining the sample, a small amount of deionized water was used for end-capping treatment for 2 h.

[0057] Toluene diisocyanate (TDI) and BP6 were dissolved in an appropriate amount of DMF at a ratio of 1.01:1, ultrasonically dispersed for 5 minutes, transferred to a three-necked flask, stirred, and 1% dibutyltin dilaurate was added dropwise. The mixture was reacted at 90°C for 20 hours. After cooling, the sample was filtered to obtain a sample, which was then rinsed twice with DMF and once with deionized water. After drying, the FLCPU sample was obtained. The diisocyanate was hexamethylene diisocyanate (HDI).

[0058] Step 3:

[0059] VMQ and FLCPU were mixed by mechanical blending, and then conductive carbon black and dipentadienyl vulcanizing agent were added in sequence. After 20 minutes, a FLCPU-modified VMQ / CCB rubber compound was obtained. The rubber compound was hot-pressed on a flat-plate vulcanizer to obtain a finished product. The hot-pressing working conditions of the flat-plate vulcanizer were 170°C, 5 minutes, and 13 MPa. The mechanical blending method was banburying, and the amount of the modifier FLCPU in the silicone rubber conductive carbon black system was controlled at 3%.

[0060] The order of adding materials in step 3 must be to blend VMQ and FLCPU first, and then add conductive carbon black and other additives in sequence to ensure that the modification effect is achieved;

[0061] Step 4: Conduct material testing on the finished product of step 3 before and after modification and extract data;

[0062] The types of testing include DSC testing, mechanical testing, scanning electron microscopy analysis and volume resistivity testing.

[0063] Example 3:

[0064] A method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material comprises the following steps:

[0065] Step 1:

[0066] First, the intermediate 4,4′-bis(β-hydroxyhexyloxy)biphenyl (BP6) was synthesized: 0.33 g of dihydroxybiphenyl was dissolved in 50 ml of ethanol with 6-chloro-1-hexanol in a molar ratio of 1:2, ultrasonically dispersed for 1 minute, and transferred to a three-necked flask. Sodium hydroxide solution was added dropwise under stirring. After completion, the mixture was filtered and washed twice with deionized water. After drying, the intermediate BP6 was obtained. 40 ml of sodium hydroxide solution was added dropwise under stirring, and the temperature was maintained at 95°C and the reaction was continued with stirring for 9 hours. The specification of the sodium hydroxide solution was 2 mol / L. The rigid structural unit of the intermediate BP6 in step 1 was an alicyclic ring. Intermediates with core compositions of different rigidities can also achieve the expected effect of this experiment.

[0067] Step 2:

[0068] Then, the synthesis of flexible liquid crystal polyurethane (FLCPU) was carried out based on step 1:

[0069] BP6 recrystallization: BP6 was dissolved in a mixed solvent, heated to boiling for 1 min, cooled to room temperature to complete the primary recrystallization, the supernatant was removed, the above mixed solvent was continued to be added, heated to boiling for 2 min, cooled to room temperature to complete the secondary crystallization, and the secondary recrystallized BP6 intermediate was obtained after drying. During the recrystallization of BP6, the mixed solvent was prepared by mixing 90 ml of ethanol and 30 ml of N-N dimethylformamide (DMF); before obtaining the sample, it was required to be end-capped with a small amount of deionized water for 2 h;

[0070] Toluene diisocyanate (TDI) and BP6 were dissolved in an appropriate amount of DMF at a ratio of 1.04:1, ultrasonically dispersed for 8 minutes, transferred to a three-necked flask, stirred, and 3% dibutyltin dilaurate was added dropwise. The mixture was reacted at 90°C for 24 hours. After cooling, the sample was filtered to obtain a sample, which was then rinsed three times with DMF and once with deionized water. After drying, the FLCPU sample was obtained. The diisocyanate was toluene diisocyanate (TDI).

[0071] Step 3:

[0072] VMQ and FLCPU were mixed mechanically, and then conductive carbon black and dipentadienyl vulcanizing agent were added in sequence. After 24 minutes, a FLCPU-modified VMQ / CCB rubber compound was obtained. The rubber compound was hot-pressed on a flat-plate vulcanizer to obtain a finished product. The hot-pressing working conditions of the flat-plate vulcanizer were 173°C, 7 minutes, and a pressure of 14 MPa. The mechanical blending methods included open mixing and internal mixing, and the amount of the modifier FLCPU in the silicone rubber conductive carbon black system was controlled at 4%.

[0073] The order of adding materials in step 3 must be to blend VMQ and FLCPU first, and then add conductive carbon black and other additives in sequence to ensure that the modification effect is achieved;

[0074] Step 4: Conduct material testing on the finished product of step 3 before and after modification and extract data;

[0075] The types of testing include DSC testing, mechanical testing, scanning electron microscopy analysis and volume resistivity testing.

[0076] Test results:

[0077] DSC curve of FLCPU

[0078] Figure 3 shows the DSC curves of the synthesized BP6 and FLCPU. In the figure, 98.4°C and 175.7°C represent the melting point Tm and the isotropic transition point (i.e., the clearing point Ti of the liquid crystal structure) of the BP6 crystalline structure, respectively. Similarly, 70.7°C and 127.2°C represent the melting point and the clearing point of the liquid crystal phase transition of the FLCPU synthesized with BP6 as the structural unit, respectively. This indicates that the synthesized flexible PU has typical liquid crystal structural characteristics, and its liquid crystal temperature range is in the range of 70-130°C.

[0079] Mechanical properties of materials before and after FLCPU modification

[0080] Figure 4 shows the mechanical stress-strain curves of the FLCPU-modified VMQ / CCB composite. As can be seen, with increasing FLCPU content, the material's modulus of tensile stress first increases and then decreases, while its elongation at break first decreases and then increases. When 4% FLCPU is added, the composite's modulus of tensile stress is significantly increased, while its tensile strength is effectively maintained, resulting in significant improvements in its overall mechanical properties.

[0081] Scanning electron microscopy analysis of FLCPU composite materials before and after modification

[0082] Figure 5 shows the dispersion of carbon black in a silicone rubber matrix before and after PU modification. As can be seen, the size of carbon black aggregates decreases after PU modification, significantly improving the dispersion of carbon black in the rubber matrix. This contributes to improved mechanical and electrical properties of the composite material.

[0083] Changes in volume resistivity of composite materials before and after FLCPU modification

[0084] Figure 6 shows the temperature variation of the volume resistivity of the VMQ / CCB composite material before and after FLCPU modification, with the corresponding values ​​shown in Table 1. As can be seen from the figure, the resistivity of the modified materials decreases significantly at the same temperature, demonstrating good conductivity enhancement. This indicates that the improved carbon black dispersion after PU modification contributes to a reduction in the overall resistivity of the material. Furthermore, as the temperature continues to rise, the composite material exhibits a significant negative temperature coefficient effect, which is attributed to the fact that heating enhances the electron mobility in the system, increasing the material's conductivity. Furthermore, the rate of decrease in the volume resistivity of the modified material with increasing temperature is significantly greater than that of the unmodified system, exhibiting a higher linear fit slope value. This indicates that the conjugated structure of the liquid crystal facilitates the migration of free electrons on the carbon black surface, improving the material's conductivity. Further observation of Table 1 shows that at temperatures exceeding 80°C, the volume resistivity of the composite material decreases sharply from more than 40% in the low temperature region to more than 60% compared to the unmodified system. This high temperature region is in the liquid crystal phase transition region, fully demonstrating the role of liquid crystal in improving the conductivity of the overall material and proving the significant effect of the conjugated structure of the mesogen in guiding or assisting the free electron migration of carbon black.

[0085] The present invention has the following beneficial effects: the preparation method of the liquid crystal synergistic high-conductive silicone rubber composite material, based on the modification of biphenyl-type liquid crystal unit structural materials, can improve the dispersion of conductive carbon black in the rubber matrix. The intermediate BP6 can be replaced by a structure containing biphenyl or polycyclic aromatic hydrocarbons, which can also achieve the expected effect of this experiment, expand the raw material selection of the product, and improve product production efficiency. The amount of the modifier in the silicone rubber conductive carbon black system is determined, and it is clarified that the FLCPU used for modification must be introduced into the rubber composite matrix by mechanical open mixing, internal mixing, extrusion, etc., and the carbon black cannot be modified by liquid phase modification of previously synthesized FLCPU and then added to the rubber, highlighting the rigorousness and accuracy of the preparation method experiment. At the same time, the conjugated structure of the liquid crystal unit can enhance the transition ability of electrons under temperature stimulation, achieving a significant synergistic effect.

[0086] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material, characterized in that: The following steps are involved: Step 1: First, the intermediate 4,4′-di(β-hydroxyhexyloxy)biphenyl (BP6) was synthesized: 0.33 g of dihydroxybiphenyl was dissolved in 50 ml of ethanol with 6-chloro-1-hexanol at a molar ratio of 1:2, ultrasonically dispersed for 1 min, transferred to a three-necked flask, and sodium hydroxide solution was added dropwise under stirring. After the reaction was completed, the mixture was filtered and washed twice with deionized water, and dried to obtain the intermediate BP6; Step 2: Then, the synthesis of flexible liquid crystal polyurethane (FLCPU) was carried out based on step 1: BP6 recrystallization: dissolve BP6 in a mixed solvent, heat and boil for 1-2 minutes, cool to room temperature to complete the first recrystallization, remove the supernatant, continue to add the above mixed solvent, heat and boil for 1-2 minutes, cool to room temperature to complete the second crystallization, and obtain the second recrystallized BP6 intermediate after drying; Dissolve toluene diisocyanate (TDI) and BP6 in an appropriate amount of DMF in a ratio of (1.01-1.05):1, disperse by ultrasonic for 5 min-10 min, transfer to a three-necked flask, stir and drop 1-4% dibutyltin dilaurate, react at 90-100° C. for 20-28 h; filter to obtain a sample after cooling, rinse the sample with DMF 2-4 times, wash with deionized water 1-2 times, and dry to obtain a FLCPU sample; Step 3: VMQ and FLCPU are mixed by mechanical blending, and then conductive carbon black and dipentadienyl vulcanizing agent are added in sequence, and then FLCPU modified VMQ / CCB mixed rubber is obtained after 20-25 minutes; the mixed rubber is hot-pressed on a flat vulcanizer to obtain a finished product; Step 4: Conduct material testing on the finished product of step 3 before and after modification and extract data.

2. The method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material according to claim 1, characterized in that: In the step 1, 40 ml of sodium hydroxide solution is added dropwise under stirring, and then the temperature is maintained at 90-100° C. and the reaction is stirred for 8-10 hours. The rigid structural unit of the intermediate BP6 in step 1 is one or more of a benzene ring, an alicyclic ring or a heterocyclic ring. Intermediates with core compositions of different rigidities can also achieve the expected effect of this experiment.

3. The method for preparing a liquid crystal synergistic high conductive silicone rubber composite material according to claim 2, characterized in that: The specification of the sodium hydroxide solution is 2-2.5 mol / L.

4. The method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material according to claim 1, characterized in that: When BP6 is recrystallized in step 2, the mixed solvent is prepared by mixing 90 ml of ethanol and 30 ml of N-N-dimethylformamide (DMF); before obtaining the sample, a small amount of deionized water is required for end-capping treatment for 2-3 hours.

5. The method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material according to claim 1, characterized in that: The diisocyanate in step 2 is any one of toluene diisocyanate (TDI) and hexamethylene diisocyanate (HDI).

6. The method for preparing a liquid crystal-synergistic high-conductive silicone rubber composite material according to claim 1, characterized in that: The hot pressing molding working conditions of the flat plate vulcanizer in step 3 are 170-175° C., lasting 5-10 minutes, and a pressure of 13-15 MPa.

7. The method for preparing a liquid crystal-synergistic highly conductive silicone rubber composite material according to claim 1, characterized in that: The mechanical blending method in step 3 includes any one or more of open mixing, internal mixing and extrusion, and the amount of the modifier FLCPU in the silicone rubber conductive carbon black system is controlled at 3-5%; the order of adding materials in step 3 must be that VMQ and FLCPU are first blended, and then other additives such as conductive carbon black are added in sequence to ensure that the modification effect is achieved.

8. The method for preparing a liquid crystal-synergistic high-conductive silicone rubber composite material according to claim 1, characterized in that: The types of detection in step 4 include DSC detection, mechanical detection, scanning electron microscope analysis and volume resistivity detection.

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