Degradable intrinsic high-thermal-conductivity epoxy resin and recovery method thereof
By introducing high thermal conductivity epoxy resins with dynamic covalent bonds of liquid crystal epoxy resins, the problem that liquid crystal epoxy resin cannot have both strength, toughness, thermal conductivity and degradation and recovery performance is solved, and a degradation and recovery performance of liquid crystal epoxy resins are prepared, achieving both high thermal conductivity and mechanical properties, and have the characteristics of reprocessable and green closed-loop recovery.
Patent Information
- Application Number
- CN202510502500.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-07-25
AI Technical Summary
The existing liquid crystal epoxy resins cannot have both strength, toughness, thermal conductivity and degradation and recovery performance, making it difficult to meet the high thermal conductivity and high frequency insulation requirements of microelectronic devices and electrical equipment.
By introducing liquid crystal epoxy and dynamic covalent bonds, a degradable highly thermally conductive epoxy resin was prepared. Cyanobenzene carboxylic acid and terephthalaldehyde were synthesized by Knoevenagel condensation reaction, combined with epoxy propylene oxide and tetrabutyl ammonium bromide, liquid crystal epoxy resin monomer was prepared, and recovered through curing and remodeling, and finally chemically degraded and recovered in aqueous NaOH solution and acetonitrile.
It achieves a balance of high thermal conductivity and mechanical properties, has the characteristics of reprocessable and green closed-loop recycling, and is suitable for industrial production.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of thermally conductive epoxy resins, and in particular to a degradable intrinsically high thermally conductive epoxy resin and a recycling method thereof. Background Art
[0002] In recent years, microelectronic devices and electrical insulation equipment have been continuously miniaturized, and traditional thermally conductive epoxy resins cannot meet the growing heat dissipation needs of high-power, high-frequency, and high-voltage insulation packaging applications due to the contradiction between thermal conductivity and dielectric and thermomechanical properties. Liquid crystal epoxy resin is a unique epoxy resin that forms an ordered structure through the self-assembly of mesogenic units and has intrinsic high-k characteristics. The special structural characteristics enable liquid crystal epoxy resin to retain the beneficial physical properties of epoxy resin while having significantly enhanced k. Therefore, liquid crystal epoxy resin has become a promising solution for thermal management, with the potential to solve key problems and technical bottlenecks that hinder the increasing miniaturization of microelectronic devices and electrical equipment.
[0003] The present invention introduces liquid crystal epoxy and dynamic covalent bonds into intrinsic high thermal conductivity epoxy resin to prepare high mechanical performance and high intrinsic thermal conductivity epoxy resin with recyclable function, solving the technical bottleneck problem of difficulty in taking into account both high thermal conductivity and excellent mechanical properties of thermally conductive polymer composite materials. The toughness, thermal conductivity and degradation and recycling performance of the intrinsic high thermal conductivity epoxy resin are regulated by adjusting the structure of cyanobiphenyl carboxylic acid. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a recyclable thermally conductive liquid crystal epoxy resin and a preparation method and application thereof, so as to solve the problem that the liquid crystal epoxy resin in the prior art cannot have strength, toughness, thermal conductivity and degradation and recycling performance at the same time.
[0005] The present invention solves the above technical problems. The present invention provides a degradable intrinsic high thermal conductivity epoxy resin obtained by the following method:
[0006] (1) terephthalaldehyde, cyanobiphenylcarboxylic acid, L-proline and a solvent are reacted at 60-80° C. for 3-5 hours. After the reaction is completed, the mixture is cooled to room temperature, filtered, recrystallized, and then dried at 60° C. for 24 hours to obtain cyanobiphenyldicarboxylic acid.
[0007] (2) After uniformly mixing cyanobiphenyl dicarboxylic acid, epichlorohydrin and tetrabutylammonium bromide, react at 80-120° C. for 1-4 hours, then adding 10 wt % -40 wt % sodium hydroxide aqueous solution at 10-30° C. and continuing the reaction for 4-8 hours. After the reaction is completed, filter, wash with water, separate the liquids, and distill the organic layer under reduced pressure to obtain a liquid crystal epoxy resin monomer.
[0008] Further, the cyanobiphenylcarboxylic acid is One of the following, the solvent is one of methanol, ethanol, tetrahydrofuran, acetonitrile, 1,4 - dioxane or N,N - dimethylformamide, and the mass ratio of terephthalaldehyde, cyanobiphenyl carboxylic acid, L - proline and the solvent is 1.00:3.34:0.04:15.00.
[0009] Furthermore, the mass ratio of cyanobiphenyl dicarboxylic acid, epichlorohydrin, tetrabutylammonium bromide and sodium hydroxide is 1.00:1.94:0.06:0.28.
[0010] Furthermore, the liquid crystal epoxy resin monomer structure is
[0011]
[0012] The present invention also provides a recovery method for the above - mentioned degradable intrinsic high - thermal - conductivity epoxy resin:
[0013] (1) Mix the liquid crystal epoxy resin monomer and the curing agent, and cure at 100 - 160 °C for 4 - 8 h to obtain an intrinsic high - thermal - conductivity epoxy resin cured product.
[0014] (2) Recycling by reshaping processing: Crush the above - mentioned epoxy resin cured product to 1 - 2 cm, and then hot - press at 80 - 100 °C and 3 - 5 MPa for 20 - 60 min to obtain the reshaped and recycled intrinsic high - thermal - conductivity epoxy resin.
[0015] (3) Recycling by chemical degradation: Immerse the above - mentioned epoxy resin cured product in a mixture of 0.1 - 0.5 mol / L NaOH aqueous solution and acetonitrile, degrade at 40 - 60 °C for 1 - 3 h, then wash with water and separate layers. After removing acetonitrile by vacuum distillation from the organic layer, the recovered terephthalaldehyde is obtained.
[0016] Furthermore, the mass ratio of the epoxy resin cured product, sodium hydroxide and acetonitrile is 1.0:2.0:0.5.
[0017] The effective beneficial effects of the present invention are as follows:
[0018] 1. The present invention introduces liquid crystal epoxy and dynamic covalent bonds (Knoevenagel condensation reaction) into the epoxy resin cross - linked network, and prepares a high - intrinsic - thermal - conductivity liquid crystal epoxy resin with reprocessability and recyclability.
[0019] 2. The degradable intrinsic high - thermal - conductivity epoxy resin prepared by the present invention can be degraded and recycled under mild conditions to obtain terephthalaldehyde and cyanobiphenyl carboxylic acid, realizing the green closed - loop recycling of the thermal - conductivity epoxy resin.
[0020] 3. The degradable intrinsic high - thermal - conductivity epoxy resin of the present invention has both excellent thermal - conductivity performance and mechanical properties. The preparation process is simple, and the recycling conditions are mild, which is suitable for industrial production. Detailed implementation mode
[0021] The present invention will be described in detail below in conjunction with specific embodiments, but the protection scope of the present invention is not limited to these embodiments.
[0022] Example 1
[0023] 134.13 g of terephthalaldehyde, 446.12 g of 4-cyano-4-biphenylcarboxylic acid, 11.61 g of L-proline and ethanol were reacted at 60 °C for 5 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyldicarboxylic acid with a yield of 92.3%.
[0024] 200.00 g of cyano-biphenyldicarboxylic acid, 388.08 g of epichlorohydrin and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then 279.63 g of 40 wt% aqueous sodium hydroxide solution was added and the reaction continued at 10 °C for 8 h. After the reaction was completed, it was filtered, washed with water, and separated. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain a liquid crystal epoxy resin monomer with a yield of 86.4% and an epoxy value of 0.29 mol / 100 g.
[0025] 100 g of the liquid crystal epoxy resin monomer and 29.75 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain an intrinsically highly thermally conductive epoxy resin cured product.
[0026] The above epoxy resin cured product was crushed to 1 - 2 cm and then hot-pressed at 100 °C and 3 MPa for 20 min to obtain a reshaped and processed recycled intrinsically highly thermally conductive epoxy resin.
[0027] The above epoxy resin cured product was degraded in a mixture of 0.1 - 0.5 mol / L aqueous NaOH solution and acetonitrile at 40 - 60 °C for 1 - 3 h, then washed with water and separated. The organic layer was distilled under reduced pressure to remove acetonitrile to obtain recycled terephthalaldehyde.
[0028] 100 g of the intrinsically highly thermally conductive epoxy resin cured product was heated and degraded in a mixture of 200 ml of 0.5 mol / L aqueous NaOH solution and 50 ml of acetonitrile at 60 °C for 1 h, then washed with water and separated. The organic layer was distilled under reduced pressure to remove acetonitrile to obtain recycled terephthalaldehyde (r-TPA).
[0029] 134.13 g of r-TPA, 446.12 g of 4-cyano-4-biphenylcarboxylic acid and 11.61 g of L-proline were dissolved in ethanol and heated under reflux at 80 °C for 3 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyldicarboxylic acid with a yield of 91.4%.
[0030] 200.00 g of cyanobiphenyl dicarboxylic acid, 388.08 g of epichlorohydrin and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% aqueous sodium hydroxide solution was added and the reaction continued at 10 °C for 8 h. After the reaction, filtration, washing with water, and liquid separation were carried out. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain a liquid crystal epoxy resin monomer with a yield of 83.4% and an epoxy value of 0.29 mol / 100 g.
[0031] 100 g of the liquid crystal epoxy resin monomer and 22 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain a recycled intrinsic high thermal conductivity epoxy resin cured product.
[0032] Example 2
[0033] 134.13 g of terephthalaldehyde, 446.12 g of 4-cyano-3-biphenylcarboxylic acid, 11.61 g of L-proline and methanol were reacted at 60 °C for 5 h. After the reaction, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyanobiphenyl dicarboxylic acid with a yield of 91.4%.
[0034] 200.00 g of cyanobiphenyl dicarboxylic acid, 388.08 g of epichlorohydrin and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% aqueous sodium hydroxide solution was added and the reaction continued at 10 °C for 8 h. After the reaction, filtration, washing with water, and liquid separation were carried out. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain a liquid crystal epoxy resin monomer with a yield of 86.4% and an epoxy value of 0.29 mol / 100 g.
[0035] 100 g of the liquid crystal epoxy resin monomer and 22 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain an intrinsic high thermal conductivity epoxy resin cured product.
[0036] The above epoxy resin cured product was crushed to 1 - 2 cm and then hot-pressed at 100 °C and 3 MPa for 20 min to obtain a reshaped and recycled intrinsic high thermal conductivity epoxy resin.
[0037] The above epoxy resin cured product was degraded in a mixture of 0.1 - 0.5 mol / L aqueous NaOH solution and acetonitrile at 40 - 60 °C for 1 - 3 h, then washed with water and separated into layers. The organic layer was distilled under reduced pressure to remove acetonitrile to obtain recycled terephthalaldehyde.
[0038] 100 g of the intrinsic high thermal conductivity epoxy resin cured product was heated and degraded in a mixture of 200 ml of 0.5 mol / L aqueous NaOH solution and 50 ml of acetonitrile at 60 °C for 1 h, then washed with water and separated into layers. The organic layer was distilled under reduced pressure to remove acetonitrile to obtain recycled terephthalaldehyde (r-TPA).
[0039] 134.13 g of r-TPA, 446.12 g of 4-cyano-4-biphenylcarboxylic acid, and 11.61 g of L-proline were dissolved in methanol and heated under reflux at 80 °C for 3 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyl dicarboxylic acid with a yield of 91.4%.
[0040] 200.00 g of cyano-biphenyl dicarboxylic acid, 388.08 g of epichlorohydrin, and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% aqueous sodium hydroxide solution was added and the reaction continued at 10 °C for 8 h. After the reaction was completed, it was filtered, washed with water, and separated. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain a liquid crystal epoxy resin monomer with a yield of 84.7% and an epoxy value of 0.29 mol / 100 g.
[0041] 100 g of the liquid crystal epoxy resin monomer and 22 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain a recycled intrinsic high thermal conductivity epoxy resin cured product.
[0042] Example 3
[0043] 134.13 g of terephthalaldehyde, 446.12 g of 4-cyano-3-biphenylcarboxylic acid, 11.61 g of L-proline, and tetrahydrofuran were reacted at 60 °C for 5 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyl dicarboxylic acid with a yield of 90.2%.
[0044] 200.00 g of cyano-biphenyl dicarboxylic acid, 388.08 g of epichlorohydrin, and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% aqueous sodium hydroxide solution was added and the reaction continued at 10 °C for 8 h. After the reaction was completed, it was filtered, washed with water, and separated. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain a liquid crystal epoxy resin monomer with a yield of 85.3% and an epoxy value of 0.29 mol / 100 g.
[0045] 100 g of the liquid crystal epoxy resin monomer and 18 g of 4,4'-diaminodiphenylsulfone were mixed and cured at 160 °C for 4 h to obtain an intrinsic high thermal conductivity epoxy resin cured product.
[0046] The above epoxy resin cured product was crushed to 1 - 2 cm and then hot-pressed at 100 °C and 3 MPa for 20 min to obtain a recycled intrinsic high thermal conductivity epoxy resin by reshaping and processing.
[0047] The above-mentioned epoxy resin cured product was degraded in a mixture of 0.1 - 0.5 mol / L NaOH aqueous solution and acetonitrile at 40 - 60 °C for 1 - 3 h, then washed with water and separated into layers. After the organic layer was distilled under reduced pressure to remove acetonitrile, the recovered terephthalaldehyde was obtained.
[0048] 100 g of the intrinsic high-thermal conductivity epoxy resin cured product was heated and degraded in a mixture of 200 ml of 0.3 mol / L NaOH aqueous solution and 50 ml of acetonitrile at 60 °C for 1 h, then washed with water and separated into layers. After the organic layer was distilled under reduced pressure to remove acetonitrile, the recovered terephthalaldehyde (r-TPA) was obtained.
[0049] 134.13 g of r-TPA, 446.12 g of 4-cyano-3-biphenylcarboxylic acid, and 11.61 g of L-proline were dissolved in tetrahydrofuran and heated under reflux at 80 °C for 3 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyldicarboxylic acid with a yield of 89.3%.
[0050] 200.00 g of cyano-biphenyldicarboxylic acid, 388.08 g of epichlorohydrin, and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% sodium hydroxide aqueous solution was added and the reaction continued at 10 °C for 8 h. After the reaction was completed, it was filtered, washed with water, and separated into layers. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain the liquid crystal epoxy resin monomer with a yield of 85.4% and an epoxy value of 0.29 mol / 100 g.
[0051] 100 g of the liquid crystal epoxy resin monomer and 18 g of 4,4'-diaminodiphenylsulfone were mixed and cured at 160 °C for 4 h to obtain the recovered intrinsic high-thermal conductivity epoxy resin cured product.
[0052] Example 4
[0053] 134.13 g of terephthalaldehyde, 446.12 g of 4-cyano-2-biphenylcarboxylic acid, 11.61 g of L-proline, and DMF were reacted at 60 °C for 5 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyldicarboxylic acid with a yield of 92.1%.
[0054] 200.00 g of cyano-biphenyldicarboxylic acid, 388.08 g of epichlorohydrin, and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% sodium hydroxide aqueous solution was added and the reaction continued at 10 °C for 8 h. After the reaction was completed, it was filtered, washed with water, and separated into layers. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain the liquid crystal epoxy resin monomer with a yield of 87.5% and an epoxy value of 0.29 mol / 100 g.
[0055] 100 g of liquid crystal epoxy resin monomer and 18 g of 4,4'-diaminodiphenyl sulfone were mixed and cured at 160 °C for 4 h to obtain an intrinsically highly thermally conductive epoxy resin cured product.
[0056] The above epoxy resin cured product was crushed to 1-2 cm and then hot-pressed at 100 °C and 3 MPa for 20 min to obtain a reshaped and processed recycled intrinsically highly thermally conductive epoxy resin.
[0057] The above epoxy resin cured product was degraded in a mixture of 0.1-0.5 mol / L NaOH aqueous solution and acetonitrile at 40-60 °C for 1-3 h, then washed with water and separated into layers. After the organic layer was distilled under reduced pressure to remove acetonitrile, the recovered terephthalaldehyde was obtained.
[0058] 100 g of the intrinsically highly thermally conductive epoxy resin cured product was heated and degraded in a mixture of 200 ml of 0.2 mol / L NaOH aqueous solution and 50 ml of acetonitrile at 60 °C for 1 h, then washed with water and separated into layers. After the organic layer was distilled under reduced pressure to remove acetonitrile, the recovered terephthalaldehyde (r-TPA) was obtained.
[0059] 134.13 g of r-TPA, 446.12 g of 4-cyano-2-biphenylcarboxylic acid, and 11.61 g of L-proline were dissolved in tetrahydrofuran and heated under reflux at 80 °C for 3 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyl dicarboxylic acid with a yield of 88.3%.
[0060] 200.00 g of cyano-biphenyl dicarboxylic acid, 388.08 g of epichlorohydrin, and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% sodium hydroxide aqueous solution was added and the reaction continued at 10 °C for 8 h. After the reaction was completed, it was filtered, washed with water, and separated into layers. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain the liquid crystal epoxy resin monomer with a yield of 84.6% and an epoxy value of 0.29 mol / 100 g.
[0061] 100 g of liquid crystal epoxy resin monomer and 18 g of 4,4'-diaminodiphenyl sulfone were mixed and cured at 160 °C for 4 h to obtain a recycled intrinsically highly thermally conductive epoxy resin cured product.
[0062] Example 5
[0063] 134.13 g of terephthalaldehyde, 446.12 g of 3-cyano-4-biphenylcarboxylic acid, 11.61 g of L-proline, and 1,4-dioxane were reacted at 60 °C for 5 h. After the reaction was completed, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyano-biphenyl dicarboxylic acid with a yield of 90.3%.
[0064] 200.00 g of cyanobiphenyl dicarboxylic acid, 388.08 g of epichlorohydrin and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% sodium hydroxide aqueous solution was added and the reaction continued at 10 °C for 8 h. After the reaction, filtration, washing with water and liquid separation were carried out. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain the liquid crystal epoxy resin monomer with a yield of 84.9% and an epoxy value of 0.29 mol / 100 g.
[0065] 100 g of the liquid crystal epoxy resin monomer and 22 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain the intrinsic high thermal conductivity epoxy resin cured product.
[0066] The above epoxy resin cured product was crushed to 1 - 2 cm and then hot-pressed at 100 °C and 3 MPa for 20 min to obtain the recycled intrinsic high thermal conductivity epoxy resin by reshaping processing.
[0067] The above epoxy resin cured product was degraded in a mixture of 0.1 - 0.5 mol / L NaOH aqueous solution and acetonitrile at 40 - 60 °C for 1 - 3 h, then washed with water and separated into layers. The organic layer was distilled under reduced pressure to remove acetonitrile to obtain the recycled terephthalaldehyde.
[0068] 100 g of the intrinsic high thermal conductivity epoxy resin cured product was heated and degraded in a mixture of 200 ml of 0.1 mol / L NaOH aqueous solution and 50 ml of acetonitrile at 60 °C for 1 h, then washed with water and separated into layers. The organic layer was distilled under reduced pressure to remove acetonitrile to obtain the recycled terephthalaldehyde (r-TPA).
[0069] 134.13 g of r-TPA, 446.12 g of 3-cyano-4-biphenylcarboxylic acid and 11.61 g of L-proline were dissolved in 1,4-dioxane and heated under reflux at 80 °C for 3 h. After the reaction, it was cooled to room temperature, filtered, recrystallized, and then dried at 60 °C for 24 h to obtain cyanobiphenyl dicarboxylic acid with a yield of 90.5%.
[0070] 200.00 g of cyanobiphenyl dicarboxylic acid, 388.08 g of epichlorohydrin and 10.00 g of tetrabutylammonium bromide were mixed evenly and reacted at 80 °C for 4 h. Then, 279.63 g of 40 wt% sodium hydroxide aqueous solution was added and the reaction continued at 10 °C for 8 h. After the reaction, filtration, washing with water and liquid separation were carried out. The organic layer was dried with anhydrous magnesium sulfate and then distilled under reduced pressure to obtain the liquid crystal epoxy resin monomer with a yield of 82.6% and an epoxy value of 0.29 mol / 100 g.
[0071] 100 g of the liquid crystal epoxy resin monomer and 22 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain the recycled intrinsic high thermal conductivity epoxy resin cured product.
[0072] Comparative Example 1
[0073] 100 g of bisphenol A epoxy resin and 26 g of 4,4'-diaminodiphenylmethane were mixed and cured at 160 °C for 4 h to obtain an epoxy resin cured product.
[0074] The degradable intrinsic high thermal conductivity epoxy resins of Examples 1 to 5 and the epoxy resin cured product of Comparative Example 1 were respectively tested for tensile strength, impact strength and thermal conductivity.
[0075] Table 1 Properties of the epoxy resin cured products of Examples 1 - 5 and Comparative Example 1
[0076] Example Tensile strength (MPa) <![CDATA[Impact strength (kJ / m 2 )]]> Thermal conductivity (W / mK) Example 1 85 27 1.51 Example 2 84 26 1.49 Example 3 86 27 1.50 Example 4 85 26 1.50 Example 5 84 26 1.50 Comparative Example 1 51 14 0.58
[0077] Table 2 Remolding processing recycling performance of the degradable intrinsic high thermal conductivity epoxy resins of Examples 1 to 5
[0078]
[0079]
[0080] Table 3 Chemical degradation recycling performance of the degradable intrinsic high thermal conductivity epoxy resins of Examples 1 to 5
[0081]
[0082]
Claims
1. A degradable intrinsic high thermal conductivity epoxy resin and its recycling method, characterized in that, It includes the following steps: (1) React terephthalaldehyde, cyanobiphenyl carboxylic acid, L-proline and a solvent at 60 - 80 °C for 3 - 5 h. After the reaction is completed, cool to room temperature, filter, recrystallize, and then dry at 60 °C for 24 h to obtain cyanobiphenyl dicarboxylic acid. (2) Mix cyanobiphenyl dicarboxylic acid, epichlorohydrin and tetrabutylammonium bromide evenly and react at 80 - 120 °C for 1 - 4 h. Then add 10wt% - 40wt% sodium hydroxide aqueous solution and continue to react at 10 - 30 °C for 4 - 8 h. After the reaction is completed, filter, wash with water, separate the liquid, and distill the organic layer under reduced pressure to obtain a liquid crystal epoxy resin monomer.
2. The biodegradable intrinsic high thermal conductivity epoxy resin and its recycling method according to claim 1, characterized in that The cyanobiphenyl carboxylic acid is one of them, the solvent is one of methanol, ethanol, tetrahydrofuran, acetonitrile, 1,4-dioxane or N,N-dimethylformamide, and the mass ratio of terephthalaldehyde, cyanobiphenyl carboxylic acid, L-proline and the solvent is 1.00:3.34:0.04:15.
00.
3. A degradable intrinsic high thermal conductivity epoxy resin and its recycling method according to claim 1, characterized in that, The mass ratio of the cyanobiphenyl dicarboxylic acid, epichlorohydrin, tetrabutylammonium bromide and sodium hydroxide is 1.00:1.94:0.06:0.
28.
4. A degradable intrinsic high thermal conductivity epoxy resin and its recycling method according to claim 1, characterized in that, The structure of the liquid crystal epoxy resin monomer is 5. A degradable intrinsic high thermal conductivity epoxy resin and its recycling method according to claim 1, characterized in that, The recycling method is (1) Mix the liquid crystal epoxy resin monomer and a curing agent and cure at 100 - 160 °C for 4 - 8 h to obtain an intrinsically highly thermally conductive epoxy resin cured product. (2) Remolding and recycling: Crush the above epoxy resin cured product to 1 - 2 cm and then hot press at 80 - 100 °C and 3 - 5 MPa for 20 - 60 min to obtain the remolded and recycled intrinsically highly thermally conductive epoxy resin. (3) Chemical degradation recycling: Degrade the above epoxy resin cured product in a mixture of 0.1 - 0.5 mol / L NaOH aqueous solution and acetonitrile at 40 - 60 °C for 1 - 3 h, then wash with water and separate the layers. Distill the organic layer under reduced pressure to remove acetonitrile to obtain the recycled terephthalaldehyde.