A thermally conductive and wear-resistant silicone composite resin and its preparation method

Abstract

The present invention provides a thermally conductive and wear-resistant silicone composite resin and a preparation method thereof, belonging to the technical field of silicone preparation; the preparation process includes the following steps: preparation of double-modified boron nitride nanosheets; preparation of MoS2@NiPS hybrid; silica modification treatment; preparation of silicone composite resin. By adding modified nano-silica, MoS2@NiPS hybrid and double-modified boron nitride nanosheets, the present invention performs triple optimization of multi-shaped filler synergy, coupling agent modification and electric field alignment, which can effectively improve the thermal conductivity and wear resistance of the silicone resin.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon preparation, and in particular to a heat-conductive and wear-resistant organosilicon composite resin and a preparation method thereof. Background Art

[0002] In the process of rapid development of modern industry and technology, silicone resin has been widely used in many fields due to its excellent properties, such as excellent weather resistance, good electrical insulation and high chemical stability. For example, it is used as electronic packaging materials in the electronic and electrical industry to effectively protect the internal precision electronic components; it is used as coatings for aircraft in the aerospace field to resist the erosion of harsh environments; and it is also used as sealing materials in automobile manufacturing to ensure the normal operation of components.

[0003] However, as various industries continue to move towards high performance and high reliability, the shortcomings of traditional silicone resins in thermal conductivity and wear resistance have gradually become prominent, becoming a key factor limiting its further expansion of application scope.

[0004] In terms of thermal conductivity, high-power electronic devices such as 5G base station chips and high-performance computer CPUs will generate a lot of heat during operation. If the heat is not dissipated in time, the device temperature will be too high, which will lead to performance degradation, shortened life and even failure. The thermal conductivity of traditional silicone resins is usually at a low level, which is difficult to meet the needs of fast and efficient heat dissipation in such high heat flux density scenarios. Although past studies have tried to add various types of thermally conductive fillers, such as metal oxides, to improve the thermal conductivity of silicone resins, these high thermal conductivity fillers are very easy to agglomerate in the silicone resin matrix, making it impossible to effectively construct the thermal conductive path and fail to significantly improve the thermal conductivity.

[0005] Wear resistance is also an important factor restricting the application of silicone resin. In the fields of machinery manufacturing, automotive parts, etc., there are many parts that need to withstand frequent friction and wear, such as engine piston seals, gear transmission parts, etc. Due to the molecular structure characteristics of silicone resin, the molecular chain is prone to breakage and slippage during long-term friction, resulting in severe wear on the material surface, affecting the normal service life and working accuracy of the parts. Although wear resistance has been improved by adding hard ceramic particles (such as SiC) and fibers (such as carbon fiber), the interface compatibility between these additives and the silicone resin matrix is ​​poor, and they are prone to fall off during friction, which accelerates the wear of the material.

[0006] It can be seen that developing a method that can effectively improve thermal conductivity and wear resistance has become an important issue that needs to be urgently solved in the current related fields. Summary of the invention

[0007] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a thermally conductive and wear-resistant silicone composite resin and a preparation method thereof.

[0008] A preparation method of a thermally conductive and wear-resistant silicone composite resin comprises the following steps:

[0009] S1: Preparation of doubly modified boron nitride nanosheets

[0010] First, sodium hydride and tetrahydrofuran are mixed and then a castor oil - tetrahydrofuran mixed solution is added dropwise to prepare sodium ricinoleate. Then, sodium ricinoleate is used to modify boron nitride nanosheets first, and then dopamine is used to modify boron nitride nanosheets to prepare doubly modified boron nitride nanosheets;

[0011] S2: Preparation of MoS2@NiPS hybrid

[0012] First, MoS2 powder is mixed and reacted with a n-butyllithium solution diluted with n-hexane, then mixed with γ-aminopropyltriethoxysilane and ethanol, and finally nickel chloride hexahydrate, ethanol and NaOH solution are added for reaction to prepare the MoS2@NiPS hybrid;

[0013] S3: Modification treatment of silica

[0014] Silica is modified using a silane coupling agent;

[0015] S4: Preparation of silicone composite resin

[0016] Methylphenyl silicone resin is mixed with xylene solvent, and then modified nano-silica, MoS2@NiPS hybrid, doubly modified boron nitride nanosheets and a platinum catalyst are added. Then, pre-curing and curing are carried out, and an intermittent pulsed electric field is applied during the pre-curing stage to prepare the silicone composite resin.

[0017] Further, step S1: Preparation of doubly modified boron nitride nanosheets specifically comprises the following steps:

[0018] S1.1: Mix 3 - 5 parts by weight of sodium hydride and 5 - 8 parts by weight of tetrahydrofuran, keep stirring under nitrogen protection for 20 - 30 min, then under nitrogen protection, dropwise add a mixed solution of castor oil and tetrahydrofuran mixed in a mass ratio of 1:2 - 3 at a rate of 1 - 2 drops / s through a constant pressure dropping funnel for 80 - 90 min. After the dropping is completed, raise the temperature to 60 - 63 °C, continue stirring and reacting for 4 - 6 h, cool down, and then centrifuge and evaporate the reaction solution to obtain sodium ricinoleate;

[0019] S1.2: Add 3 - 5 parts by weight of sodium ricinoleate into a mixture of 10 - 12 parts by weight of 95:5 v / v anhydrous ethanol and deionized water, stir at 50 - 60 °C for 30 - 40 min, then add 5 - 8 parts by weight of boron nitride nanosheets, continue to stir for 2 - 3 h. After the reaction, wash with anhydrous ethanol 2 - 3 times, and then dry at 80 - 90 °C for 16 - 19 h to obtain preliminarily modified boron nitride nanosheets;

[0020] S1.3: Add 2 - 3 parts by weight of the preliminarily modified boron nitride nanosheets into 50 - 60 parts by weight of deionized water, then ultrasonically disperse at 200 - 300 W and 40 - 50 kHz for 20 - 30 min to obtain a suspension;

[0021] S1.4: Dissolve 0.2 - 0.4 parts by weight of hydrochloric acid dopamine in 20 - 30 parts by weight of Tris buffer solution with pH 8.5 to obtain a dopamine solution. Mix the suspension and the dopamine solution in a volume ratio of 1:1, then magnetically stir at 25 - 26 °C for 24 - 30 h, and then perform centrifugation, washing, and drying to obtain double - modified boron nitride nanosheets.

[0022] Further, step S2: Preparation of MoS2@NiPS hybrid, specifically including the following steps:

[0023] S2.1: Mix 2 - 3 parts by weight of MoS2 powder and 36 - 42 parts by weight of n - butyllithium solution, react in a reaction kettle at 80 - 90 °C for 4 - 5 h. After cooling, filter, then rinse with n - hexane, and then dry to obtain Li x MoS2, where the n - butyllithium solution is a n - butyllithium solution diluted to a concentration of 0.5 M with n - hexane;

[0024] S2.2: Add 1 - 2 parts by weight of Li x MoS2 into 200 - 230 parts by weight of deionized water, then perform ultrasonic treatment for 4 - 5 h to obtain a suspension. Add 50 - 60 parts by weight of ethanol into 0.2 - 0.3 parts by weight of γ - aminopropyltriethoxysilane, stir and mix, and then add it into the suspension, and continuously stir for 4 - 5 h to obtain a mixed system;

[0025] S2.3: Add 0.5 - 0.6 parts by weight of nickel chloride hexahydrate and 50 - 60 parts by weight of ethanol into the mixed system, then add 11.1 - 11.2 parts by weight of 1 M NaOH solution, continuously stir for 20 - 30 min, stop stirring and let it stand for 3 - 4 min, then place it for aging for 72 - 78 h, and obtain the MoS2@NiPS hybrid through centrifugation, drying, and grinding.

[0026] Further, step S3: Silica modification treatment, specifically including the following steps:

[0027] S3.1: Add 1-2 parts by weight of nano-silica into 30-40 parts by weight of absolute ethanol, stir and mix at room temperature for 20-30 min to obtain a silica dispersion liquid. Add 5-8 parts by weight of silane coupling agent KH550 into 10-18 parts by weight of deionized water, and then stir and mix for 20-30 min to obtain a silane coupling agent mixed liquid.

[0028] S3.2: After mixing the silane coupling agent mixed liquid and the silica dispersion liquid, stir and mix at 400-500 r / min for 1-2 h, and then carry out a condensation reflux reaction at 70-72 °C for 3-4 h. After the reaction, wash with absolute ethanol, filter by suction, and dry in vacuum to obtain modified nano-silica.

[0029] Further, step S4: Preparation of the organosilicon composite resin, which specifically includes the following steps:

[0030] S4.1: Mix methylphenyl silicone resin and xylene solvent in a mass ratio of 1:1, stir until completely dissolved to obtain a resin solution. Then add the modified nano-silica, MoS2@NiPS hybrid, and double-modified boron nitride nanosheets into the resin solution, ultrasonically disperse for 20-30 min, and then stir at 2000-3000 rpm for 20-30 min to obtain a mixture.

[0031] S4.2: Add 0.05-0.3 wt% of platinum catalyst to the mixture, stir for 10-12 min to obtain a slurry. Then pour the slurry into a mold, pre-cure at 80-90 °C for 1-2 h in a vacuum environment, and then cure at 150-160 °C for 2-3 h to obtain the organosilicon composite resin.

[0032] Further, in step S4.1, the addition amount of the modified nano-silica is 5-10 wt% of the resin solution, the addition amount of the MoS2@NiPS hybrid is 3-8 wt% of the resin solution, and the addition amount of the double-modified boron nitride nanosheets is 10-15 wt% of the resin solution.

[0033] Further, in step S4.2, during the pre-curing stage of the resin, an intermittent pulse is adopted, a pulsed electric field is applied, turned on for 30-40 s, turned off for 5-10 s, voltage amplitude: 5-8 kV, frequency: 100-300 Hz, time 1-2 h.

[0034] A thermally conductive and wear-resistant organosilicon composite resin is prepared by the preparation method of a thermally conductive and wear-resistant organosilicon composite resin described in any one of the above.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] 1. The present invention uses castor oil to prepare the surface modifier sodium ricinoleate, and modifies boron nitride nanosheets with sodium ricinoleate. Then, it is further modified with dopamine hydrochloride. The double-modified boron nitride nanosheets are added to the silicone resin. Sodium ricinoleate improves the compatibility between boron nitride nanosheets and the silicone resin, reduces agglomeration, and promotes uniform dispersion. The strong adhesion of polydopamine forms a flexible interfacial layer on the surface of boron nitride nanosheets, which binds to the matrix through hydrogen bonds and covalent bonds, enhancing the filler-matrix interfacial strength. The double modification prevents the nanosheets from falling off during friction, reduces stress concentration, and delays crack propagation, thereby improving wear resistance. The double-modified boron nitride nanosheets are more likely to form an ordered arrangement during processing, increasing the phonon conduction path and improving the in-plane thermal conductivity. The polydopamine coating, as a "molecular bridge", reduces phonon scattering between the filler and the matrix through strong interfacial bonding, further reducing the interfacial thermal resistance. The synergistic effect of the double modification can significantly improve the overall thermal conductivity of the composite material.

[0037] 2. The present invention adds a hybrid of MoS2 modified with NiPS. The layered structure and high intrinsic thermal conductivity of MoS2 can form a thermal conduction channel in the resin matrix, while the modification of NiPS can optimize its dispersion, reduce the interfacial thermal resistance, and promote efficient heat transfer. NiPS can bind to MoS2 through chemical bonds, enhancing the interfacial compatibility between the hybrid and the silicone resin, reducing phonon scattering, and thus improving the overall thermal performance. The layered structure of MoS2 can form a transfer film on the friction surface, significantly reducing the friction coefficient. After being modified with NiPS, MoS2 is prevented from falling off due to mechanical shear, prolonging the lubrication life. Therefore, adding a hybrid of MoS2 modified with NiPS can effectively improve the thermal conductivity and wear resistance of silicone.

[0038] 3. The present invention adds silica modified with a coupling agent to the preparation of silicone resin. The silica modified with the coupling agent can be dispersed in boron nitride nanosheets and the hybrid of MoS2 modified with NiPS. The granular silica, flaky boron nitride nanosheets, and MoS2@NiPS hybrid are connected to form a thermal conduction path. Compared with a single-shaped thermal conductive filler, mixing different-shaped thermal conductive fillers increases the possibility of contact between the fillers, making the constructed thermal conduction network more continuous. The in-plane heat transfer of the flaky filler and the point-plane connection of the granular filler work together to construct a three-dimensional network, effectively improving the thermal conductivity. In addition, the added silica modified with the coupling agent can bind to the surfaces of boron nitride nanosheets and the MoS2@NiPS hybrid. After being modified with the coupling agent, the silica also binds more tightly to the resin interface, enhancing the overall structural stability and improving the wear resistance of silicone at the same time.

[0039] 4. In the resin pre-curing stage of the present invention, an intermittent pulsed electric field is applied. The pulsed electric field causes the polar conductive fillers to align along the electric field direction. The oriented flaky fillers form continuous channels parallel to the heat flow direction, maximizing the in-plane heat conduction advantage. The electric field effect can break the random distribution of the fillers, reconstruct a more efficient heat conduction network, reduce the gaps and misalignments between the fillers. Through the triple optimization of the cooperation of multi-shaped fillers, coupling agent modification, and electric field alignment, the thermal conductivity of the silicone resin can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings incorporated herein and constituting a part of the specification illustrate embodiments of the present invention and, together with the specification, are further used to explain the principles of the present invention and enable those skilled in the relevant art to implement and use the present invention.

[0041] Figure 1 It is a flowchart of a preparation method of a thermally conductive and wear-resistant silicone composite resin adopted in an embodiment of the present invention.

[0042] Figure 2 It is a reaction schematic diagram of MoS2@NiPS hybrid of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] The following describes in detail a thermally conductive and wear-resistant silicone composite resin and a preparation method thereof provided by the present invention in combination with the accompanying drawings and specific embodiments. At the same time, it should be noted here that in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments. For some well-known technologies, those skilled in the art can also adopt other alternative methods for implementation; moreover, the drawing part is only for more specifically describing the embodiments and is not intended to specifically limit the present invention.

[0044] Sodium ricinoleate structural formula:

[0045]

[0046] Example 1

[0047] A preparation method of a thermally conductive and wear-resistant silicone composite resin, as Figure 1 - Figure 2 shown, includes the following steps:

[0048] S1: Preparation of double-modified boron nitride nanosheets

[0049] S1.1: After mixing 3 parts by weight of sodium hydride and 5 parts by weight of tetrahydrofuran, under nitrogen protection, keep stirring for 20 min. Then, under nitrogen protection, dropwise add a mixed solution of castor oil and tetrahydrofuran mixed in a mass ratio of 1:2 through a constant pressure dropping funnel at a rate of 1 drop / s for 80 min. After the dropping is completed, raise the temperature to 60 °C, continue stirring and reacting for 4 h, cool down, and then centrifuge and evaporate the reaction solution to obtain sodium ricinoleate;

[0050] S1.2: Add 3 parts by weight of sodium ricinoleate to a mixture of 10 parts by weight of a 95:5 v / v anhydrous ethanol and deionized water mixture, stir at 50 °C for 30 min, then add 5 parts by weight of boron nitride nanosheets, continue stirring for 2 h. After the reaction is completed, wash twice with anhydrous ethanol, and then dry at 80 °C for 16 h to obtain preliminarily modified boron nitride nanosheets;

[0051] S1.3: Add 2 parts by weight of the preliminarily modified boron nitride nanosheets to 50 parts by weight of deionized water, and then ultrasonically disperse at 200 W and 40 kHz for 20 min to obtain a suspension;

[0052] S1.4: Dissolve 0.2 parts by weight of dopamine hydrochloride in 20 parts by weight of Tris buffer solution with pH 8.5 to obtain a dopamine solution. After mixing the suspension and the dopamine solution in a volume ratio of 1:1, stir magnetically at 25 °C for 24 h, then carry out centrifugation, washing, and drying to obtain double-modified boron nitride nanosheets;

[0053] S2: Preparation of MoS2@NiPS hybrid

[0054] S2.1: Mix 2 parts by weight of MoS2 powder and 36 parts by weight of n-butyllithium solution, react in an 80 °C reaction kettle for 4 h, cool, filter, then rinse with n-hexane, and then dry to obtain Li x MoS2, where the n-butyllithium solution is an n-butyllithium solution diluted to a concentration of 0.5 M with n-hexane;

[0055] S2.2: Add 1 part by weight of Li x MoS2 to 200 parts by weight of deionized water, then ultrasonically treat for 4 h to obtain a suspension. Add 50 parts by weight of ethanol to 0.2 parts by weight of γ-aminopropyltriethoxysilane, stir and mix, and then add to the suspension, and continuously stir for 4 h to obtain a mixed system;

[0056] S2.3: Add 0.5 parts by weight of nickel chloride hexahydrate and 50 parts by weight of ethanol to the mixed system, then add 11.1 parts by weight of 1 M NaOH solution, continuously stir for 20 min, stop stirring and let stand for 3 min, then place for aging for 72 h, and obtain the MoS2@NiPS hybrid through centrifugation, drying, and grinding;

[0057] S3: Silica modification treatment

[0058] S3.1: Add 1 part by weight of nano-silica into 30 parts by weight of absolute ethanol, stir and mix at room temperature for 20 min to obtain a silica dispersion. Add 5 parts by weight of silane coupling agent KH550 into 10 parts by weight of deionized water, then stir and mix for 20 min to obtain a silane coupling agent mixture.

[0059] S3.2: After mixing the silane coupling agent mixture and the silica dispersion, stir and mix at 400 r / min for 1 h, then under the condition of 70 °C, carry out a condensation reflux reaction for 3 h. After the reaction, wash with absolute ethanol, filter by suction, and dry in vacuum to obtain modified nano-silica.

[0060] S4: Preparation of organosilicon composite resin

[0061] S4.1: Mix methylphenyl silicone resin and xylene solvent according to a mass ratio of 1:1, stir until completely dissolved to obtain a resin solution. Then add modified nano-silica, MoS2@NiPS hybrid, and double-modified boron nitride nanosheets into the resin solution, ultrasonically disperse for 20 min, and then stir at 2000 rpm for 20 min to obtain a mixture.

[0062] The addition amount of modified nano-silica is 5 wt% of the resin solution, the addition amount of MoS2@NiPS hybrid is 3 wt% of the resin solution, and the addition amount of double-modified boron nitride nanosheets is 10 wt% of the resin solution.

[0063] S4.2: Add 0.05 wt% of platinum catalyst to the mixture, stir for 10 min to obtain a slurry. Then pour the slurry into a mold, pre-cure at 80 °C for 1 h under a vacuum environment, and then cure at 150 °C for 2 h to obtain an organosilicon composite resin.

[0064] In the resin pre-curing stage, adopt intermittent pulses, apply a pulsed electric field, turn on for 30 s, turn off for 5 s, voltage amplitude: 5 kV, frequency: 100 Hz, time: 1 h.

[0065] Example 2

[0066] A preparation method of a thermally conductive and wear-resistant organosilicon composite resin, as Figure 1 - Figure 2 shown, includes the following steps:

[0067] S1: Preparation of double-modified boron nitride nanosheets

[0068] S1.1: Mix 5 parts by weight of sodium hydride and 8 parts by weight of tetrahydrofuran, keep stirring under nitrogen protection for 20 min, then, under nitrogen protection, add dropwise a mixed solution of castor oil and tetrahydrofuran with a mass ratio of 1:3 through a constant-pressure dropping funnel at a rate of 2 drops / s for 80 min. After the addition is complete, raise the temperature to 60 °C and continue stirring and reacting for 4 h. After cooling, centrifuge and evaporate the reaction solution to obtain sodium ricinoleate;

[0069] S1.2: Add 5 parts by weight of sodium ricinoleate to a mixed solution of 12 parts by weight of 95:5 v / v anhydrous ethanol and deionized water, stir at 50 °C for 30 min, then add 5 - 8 parts by weight of boron nitride nanosheets, continue stirring for 2 h. After the reaction is completed, wash twice with anhydrous ethanol, and then dry at 80 °C for 16 h to obtain preliminarily modified boron nitride nanosheets;

[0070] S1.3: Add 3 parts by weight of preliminarily modified boron nitride nanosheets to 60 parts by weight of deionized water, and then ultrasonically disperse at 200 W and 40 kHz for 20 min to obtain a suspension;

[0071] S1.4: Dissolve 0.4 parts by weight of hydrochloric acid dopamine in 30 parts by weight of Tris buffer solution with pH 8.5 to obtain a dopamine solution. Mix the suspension and the dopamine solution in a volume ratio of 1:1, stir magnetically at 25 °C for 24 h, then centrifuge, wash, and dry to obtain double-modified boron nitride nanosheets;

[0072] S2: Preparation of MoS2@NiPS hybrid

[0073] S2.1: Mix 3 parts by weight of MoS2 powder and 42 parts by weight of n-butyllithium solution, react in an 80 °C reaction kettle for 4 h, cool, filter, then rinse with n-hexane, and then dry to obtain Li x MoS2, where the n-butyllithium solution is an n-butyllithium solution diluted to a concentration of 0.5 M with n-hexane;

[0074] S2.2: Add 2 parts by weight of Li x MoS2 to 230 parts by weight of deionized water, then ultrasonically treat for 4 h to obtain a suspension. Add 60 parts by weight of ethanol to 0.3 parts by weight of γ-aminopropyltriethoxysilane, stir and mix, and then add to the suspension, and continue stirring for 4 h to obtain a mixed system;

[0075] S2.3: Add 0.6 parts by weight of nickel chloride hexahydrate and 60 parts by weight of ethanol to the mixed system, then add 11.2 parts by weight of 1 M NaOH solution, continue stirring for 20 min, stop stirring and let stand for 3 min, then place for aging for 72 h, and obtain the MoS2@NiPS hybrid through centrifugation, drying and grinding;

[0076] S3: Silica modification treatment

[0077] S3.1: Add 2 parts by weight of nano-silica into 40 parts by weight of absolute ethanol, stir and mix at room temperature for 20 min to obtain a silica dispersion liquid. Add 8 parts by weight of silane coupling agent KH550 into 18 parts by weight of deionized water, then stir and mix for 20 min to obtain a silane coupling agent mixed liquid;

[0078] S3.2: After mixing the silane coupling agent mixed liquid and the silica dispersion liquid, stir and mix at 400 r / min for 1 h, then under the condition of 70 °C, carry out a condensation reflux reaction for 3 h. After the reaction is completed, wash with absolute ethanol, filter by suction, and dry in vacuum to obtain modified nano-silica;

[0079] S4: Preparation of organosilicon composite resin

[0080] S4.1: Mix methylphenyl silicone resin and xylene solvent according to a mass ratio of 1:1, stir until completely dissolved to obtain a resin solution. Then add modified nano-silica, MoS2@NiPS hybrid, and double-modified boron nitride nanosheets into the resin solution, ultrasonically disperse for 20 min, and then stir at 2000 rpm for 20 min to obtain a mixture;

[0081] The addition amount of modified nano-silica is 10 wt% of the resin solution, the addition amount of MoS2@NiPS hybrid is 8 wt% of the resin solution, and the addition amount of double-modified boron nitride nanosheets is 15 wt% of the resin solution;

[0082] S4.2: Add 0.3 wt% of platinum catalyst into the mixture, stir for 10 min to obtain a slurry. Then pour the slurry into a mold, pre-cure at 80 °C for 1 h under a vacuum environment, and then cure at 150 °C for 2 h to obtain an organosilicon composite resin;

[0083] In the resin pre-curing stage, adopt intermittent pulses, apply a pulsed electric field, turn on for 30 s, turn off for 5 s, voltage amplitude: 5 kV, frequency: 100 Hz, time: 1 h.

[0084] Example 3

[0085] A preparation method of a thermally conductive and wear-resistant organosilicon composite resin, as Figure 1 - Figure 2 shown, includes the following steps:

[0086] S1: Preparation of double-modified boron nitride nanosheets

[0087] S1.1: Mix 3 parts by weight of sodium hydride and -8 parts by weight of tetrahydrofuran, keep stirring under nitrogen protection for 30 min, then, under nitrogen protection, dropwise add a mixed solution of castor oil and tetrahydrofuran mixed at a mass ratio of 1:2 through a constant pressure dropping funnel at a rate of 1 drop / s for 90 min. After the addition is completed, raise the temperature to 63 °C and continue stirring and reacting for 6 h. After cooling, centrifuge and evaporate the reaction solution to obtain sodium ricinoleate;

[0088] S1.2: Add 3 parts by weight of sodium ricinoleate to a mixed solution of 10 parts by weight of 95:5 v / v anhydrous ethanol and deionized water, stir at 60 °C for 40 min, then add 5 parts by weight of boron nitride nanosheets, continue stirring for 3 h. After the reaction is completed, wash 3 times with anhydrous ethanol, and then dry at 90 °C for 19 h to obtain preliminarily modified boron nitride nanosheets;

[0089] S1.3: Add 2 parts by weight of preliminarily modified boron nitride nanosheets to 50 parts by weight of deionized water, and then ultrasonically disperse at 300 W and 50 kHz for 30 min to obtain a suspension;

[0090] S1.4: Dissolve 0.2 parts by weight of hydrochloric acid dopamine in 20 parts by weight of Tris buffer solution with pH 8.5 to obtain a dopamine solution. Mix the suspension and the dopamine solution in a volume ratio of 1:1, magnetically stir at 26 °C for 30 h, then centrifuge, wash, and dry to obtain double-modified boron nitride nanosheets;

[0091] S2: Preparation of MoS2@NiPS hybrid

[0092] S2.1: Mix 2 parts by weight of MoS2 powder and 36 parts by weight of n-butyllithium solution, react in a reaction kettle at 90 °C for 5 h, cool, filter, then rinse with n-hexane, and then dry to obtain Li x MoS2, where the n-butyllithium solution is an n-butyllithium solution diluted to a concentration of 0.5 M with n-hexane;

[0093] S2.2: Add 1 part by weight of Li x MoS2 to 200 parts by weight of deionized water, then ultrasonically treat for 5 h to obtain a suspension. Add 50 parts by weight of ethanol to 0.2 parts by weight of γ-aminopropyltriethoxysilane, stir and mix, and then add to the suspension, and continuously stir for 5 h to obtain a mixed system;

[0094] S2.3: Add 0.5 parts by weight of nickel chloride hexahydrate and 50 parts by weight of ethanol to the mixed system, then add 11.1 parts by weight of 1 M NaOH solution, continuously stir for 30 min, stop stirring and let stand for 4 min, then place for aging for 8 h, and obtain the MoS2@NiPS hybrid through centrifugation, drying, and grinding;

[0095] S3: Silica modification treatment

[0096] S3.1: Add 1 part by weight of nano-silica into 30 parts by weight of absolute ethanol, stir and mix at room temperature for 30 min to obtain a silica dispersion liquid. Add 5 parts by weight of silane coupling agent KH550 into 10 parts by weight of deionized water, then stir and mix for 30 min to obtain a silane coupling agent mixed liquid;

[0097] S3.2: After mixing the silane coupling agent mixed liquid and the silica dispersion liquid, stir and mix at 500 r / min for 2 h, then under the condition of 72 °C, carry out a condensation reflux reaction for 4 h. After the reaction ends, wash with absolute ethanol, filter by suction, and dry in vacuum to obtain modified nano-silica;

[0098] S4: Preparation of organosilicon composite resin

[0099] S4.1: Mix methylphenyl silicone resin and xylene solvent according to a mass ratio of 1:1, stir until completely dissolved to obtain a resin solution. Then add modified nano-silica, MoS2@NiPS hybrid, and double-modified boron nitride nanosheets into the resin solution, carry out ultrasonic dispersion for 30 min, and then stir at 3000 rpm for 30 min to obtain a mixture;

[0100] The addition amount of modified nano-silica is 5 wt% of the resin solution, the addition amount of MoS2@NiPS hybrid is 3 wt% of the resin solution, and the addition amount of double-modified boron nitride nanosheets is 10 wt% of the resin solution;

[0101] S4.2: Add 0.05 wt% of platinum catalyst into the mixture, stir for 12 min to obtain a slurry. Then pour the slurry into a mold, under a vacuum environment, pre-cure at 90 °C for 2 h, and then cure at 160 °C for 3 h to obtain an organosilicon composite resin;

[0102] In the resin pre-curing stage, adopt an intermittent pulse, apply a pulsed electric field, turn on for 40 s, turn off for 10 s, voltage amplitude: 8 kV, frequency: 300 Hz, time 2 h.

[0103] Comparative Example 1

[0104] Compared with Example 1, the difference in Comparative Example 1 is that Comparative Example 1 removes steps S1.1 - S1.2, and replaces the preliminarily modified boron nitride nanosheets in step S1.3 with boron nitride nanosheets, and the remaining steps remain unchanged to prepare an organosilicon composite resin, denoted as Comparative Example 1.

[0105] Comparative Example 2

[0106] Compared with Example 1, the difference in Comparative Example 2 is that Comparative Example 2 removes steps S1.3 - S1.4, replaces the double - modified boron nitride nanosheets in step S4.1 with preliminarily modified boron nitride nanosheets, and prepares the silicone composite resin with the remaining steps unchanged, denoted as Comparative Example 2.

[0107] Comparative Example 3

[0108] Compared with Example 1, the difference in Comparative Example 3 is that Comparative Example 3 removes step S1, replaces the double - modified boron nitride nanosheets in S4.1 with boron nitride nanosheets, and prepares the silicone composite resin with the remaining steps unchanged, denoted as Comparative Example 3.

[0109] Comparative Example 4

[0110] Compared with Example 1, the difference in Comparative Example 4 is that Comparative Example 4 removes the MoS2@NiPS hybrids in steps S2 and S4.1, and prepares the silicone composite resin with the remaining steps unchanged, denoted as Comparative Example 4.

[0111] Comparative Example 5

[0112] Compared with Example 1, the difference in Comparative Example 5 is that Comparative Example 5 removes step S2, replaces the MoS2@NiPS hybrids in S4.1 with a mixture of MoS2 and NiPS, and prepares the silicone composite resin with the remaining steps unchanged, denoted as Comparative Example 5.

[0113] Comparative Example 6

[0114] Compared with Example 1, the difference in Comparative Example 6 is that Comparative Example 6 removes the modified nano - silica in steps S3 and S4.1, and prepares the silicone composite resin with the remaining steps unchanged, denoted as Comparative Example 6.

[0115] Comparative Example 7

[0116] Compared with Example 1, the difference in Comparative Example 7 is that Comparative Example 7 removes the intermittent pulsed electric field in step S4.2, and prepares the silicone composite resin with the remaining steps unchanged, denoted as Comparative Example 7.

[0117] The silicone composite resins prepared in Examples 1 - 3 and Comparative Examples 1 - 6 were subjected to wear resistance tests. The wear resistance was determined according to the Ford FLTM - BN - 108 - 13 scratch resistance standard, and tested using a wear resistance tester. All scratches were inspected according to the grade evaluation. Among them, grade 1 is the best (no scratches), and grade 5 is the worst (severe scratches). The test results are shown in Table 1.

[0118] Table 1. Wear resistance test results of silicone composite resins

[0119]

[0120] From the data in Table 1 and Comparative Examples 1-3, it can be seen that the wear resistance of boron nitride nanosheets after dual modification is improved compared to single modification. From the data in Comparative Examples 4 and 5, it can be seen that the MoS2 hybrid modified with NiPS has a better effect on improving the wear resistance than simple physical mixing. From the data in Comparative Example 6, it can be seen that the addition of modified silica effectively improves the wear resistance of silicone resin.

[0121] The thermal conductivity of the silicone composite resins prepared in Examples 1-3 and Comparative Examples 1-7 was tested, and the test results are shown in Table 2 for reference.

[0122] Table 2. Test Results of Thermal Conductivity of Silicone Composite Resins

[0123]

[0124] From the data in Table 2 and Comparative Examples 1-3, it can be seen that the boron nitride nanosheets after dual modification can significantly improve the overall thermal conductivity of the composite material. From the data in Comparative Examples 4-5, it can be seen that the addition of the MoS2 hybrid modified with NiPS can effectively improve the thermal conductivity of silicone, while simple physical mixing reduces the thermal conductivity of silicone. From the data in Comparative Example 6, it can be seen that adding silica modified with a coupling agent to the preparation of silicone resin effectively improves the thermal conductivity. From the data in Comparative Example 7, it can be seen that applying an intermittent pulsed electric field can effectively improve the thermal conductivity of silicone resin.

[0125] The above embodiments merely illustrate the principles and effects of the present invention, rather than limiting the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes completed by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing a heat-conductive and wear-resistant organic silicon composite resin, characterized in that: The steps include: S1: Preparation of doubly modified boron nitride nanosheets Firstly, sodium hydride and tetrahydrofuran are mixed and then a castor oil-tetrahydrofuran mixed solution is added dropwise to prepare sodium ricinoleate, and then the boron nitride nanosheets are modified by sodium ricinoleate and then the boron nitride nanosheets are modified by dopamine to prepare double-modified boron nitride nanosheets; S2: Preparation of MoS2@NiPS hybrid MoS2 powder was first mixed with n-butyl lithium solution diluted with n-hexane for reaction, then mixed with γ-aminopropyltriethoxysilane and ethanol, and finally nickel chloride hexahydrate, ethanol and NaOH solution were added to react to prepare MoS2@NiPS hybrid; S3: Silica modification treatment The silicon dioxide is modified by using a silane coupling agent; S4: Preparation of silicone composite resin After the methylphenyl silicone resin is mixed with the xylene solvent, modified nano-silica, MoS2@NiPS hybrid, double modified boron nitride nanosheets and platinum catalyst are added, followed by pre-curing and curing. During the pre-curing stage, an intermittent pulse electric field is applied, which is turned on for 30-40s and turned off for 5-10s, with a voltage amplitude of 5-8kV, a frequency of 100-300Hz, and a time of 1-2h to prepare a silicone composite resin.

2. The method for preparing a heat-conductive and wear-resistant organic silicon composite resin according to claim 1, characterized in that: Step S1: Preparation of double-modified boron nitride nanosheets, specifically comprising the following steps: S1.1: After mixing 3-5 parts by weight of sodium hydride and 5-8 parts by weight of tetrahydrofuran, keep stirring under nitrogen protection for 20-30 minutes, then add a mixed solution of castor oil and tetrahydrofuran in a mass ratio of 1:2-3 through a constant pressure dropping funnel at 1-2 drops / s under nitrogen protection for 80-90 minutes. After the addition is complete, heat to 60-63°C, continue stirring and react for 4-6 hours, cool the reaction solution, centrifuge and evaporate to obtain sodium ricinoleate; S1.2: Add 3-5 parts by weight of sodium ricinoleate to 10-12 parts by weight of a 95:5 v / v mixture of anhydrous ethanol and deionized water, stir at 50-60°C for 30-40 min, then add 5-8 parts by weight of boron nitride nanosheets, continue stirring for 2-3 hours, and after the reaction is completed, wash with anhydrous ethanol 2-3 times, and then dry at 80-90°C for 16-19 hours to obtain the initially modified boron nitride nanosheets; S1.3: adding 2-3 parts by weight of the preliminarily modified boron nitride nanosheets to 50-60 parts by weight of deionized water, and then ultrasonically dispersing at 200-300 W and 40-50 kHz for 20-30 min to obtain a suspension; S1.4: Dissolve 0.2-0.4 parts by weight of dopamine hydrochloride in 20-30 parts by weight of Tris buffer at pH 8.5 to obtain a dopamine solution, mix the suspension with the dopamine solution in a volume ratio of 1:1, and stir magnetically at 25-26°C for 24-30 hours, then centrifuge, wash, and dry to obtain double-modified boron nitride nanosheets.

3. The method for preparing a heat-conductive and wear-resistant organic silicon composite resin according to claim 2, characterized in that: Step S2: Preparation of MoS2@NiPS hybrid, specifically comprising the following steps: S2.1: Mix 2-3 parts by weight of MoS2 powder and 36-42 parts by weight of n-butyl lithium solution and react in a reactor at 80-90°C for 4-5 hours. After cooling, filter, rinse with n-hexane, and then dry to obtain Li x MoS2, wherein the n-butyl lithium solution is a n-butyl lithium solution diluted to a concentration of 0.5 M using n-hexane; S2.2: 1-2 parts by weight of Li x MoS2 is added to 200-230 parts by weight of deionized water, and then ultrasonically treated for 4-5 hours to obtain a suspension, 50-60 parts by weight of ethanol is added to 0.2-0.3 parts by weight of γ-aminopropyltriethoxysilane, stirred and mixed, and then added to the suspension, and stirred for 4-5 hours to obtain a mixed system; S2.3: Add 0.5-0.6 parts by weight of nickel chloride hexahydrate and 50-60 parts by weight of ethanol to the mixed system, and then add 11.1-11.2 parts by weight of 1M NaOH solution, continue stirring for 20-30 minutes, stop stirring and let stand for 3-4 minutes, then age for 72-78 hours, and obtain MoS2@NiPS hybrid after centrifugation, drying and grinding.

4. The method for preparing a heat-conductive and wear-resistant organic silicon composite resin according to claim 3, characterized in that: Step S3: silicon dioxide modification treatment, specifically comprising the following steps: S3.1: Add 1-2 parts by weight of nano-silicon dioxide to 30-40 parts by weight of anhydrous ethanol, stir and mix for 20-30 minutes at room temperature to obtain a silicon dioxide dispersion, add 5-8 parts by weight of silane coupling agent KH550 to 10-18 parts by weight of deionized water, and then stir and mix for 20-30 minutes to obtain a silane coupling agent mixed solution; S3.2: After mixing the silane coupling agent mixed liquid and the silica dispersion liquid, stir and mix at 400-500r / min for 1-2h, then condense and reflux for 3-4h at 70-72℃. After the reaction, wash with anhydrous ethanol, filter and vacuum dry to obtain modified nano-silica.

5. The method for preparing a heat-conductive and wear-resistant organic silicon composite resin according to claim 4, characterized in that: Step S4: Preparation of organic silicon composite resin, specifically comprising the following steps: S4.1: Mix methylphenyl silicone resin and xylene solvent in a mass ratio of 1:1, stir until completely dissolved to obtain a resin solution, then add modified nano-silica, MoS2@NiPS hybrid and double-modified boron nitride nanosheets to the resin solution, ultrasonically disperse for 20-30 minutes, and then stir at 2000-3000 rpm for 20-30 minutes to obtain a mixture; S4.2: Add 0.05-0.3wt% platinum catalyst to the mixture and stir for 10-12 minutes to obtain slurry. Then pour the slurry into a mold and pre-cure it at 80-90℃ for 1-2h in a vacuum environment. Then cure it at 150-160℃ for 2-3h to obtain a silicone composite resin.

6. The method for preparing a heat-conductive and wear-resistant organic silicon composite resin according to claim 5, characterized in that: In step S4.1, the amount of modified nano-silica added is 5-10wt% of the resin solution, the amount of MoS2@NiPS hybrid added is 3-8wt% of the resin solution, and the amount of double-modified boron nitride nanosheets added is 10-15wt% of the resin solution.

7. A thermally conductive and wear-resistant organic silicon composite resin, characterized in that: The thermally conductive and wear-resistant organic silicon composite resin is prepared by the method for preparing the thermally conductive and wear-resistant organic silicon composite resin according to any one of claims 1 to 6.

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