Polysiloxane functionalized aluminum nitride modified epoxy resin and preparation method thereof

Abstract

The invention relates to the technical field of epoxy resin, and discloses polysiloxane functionalized aluminum nitride modified epoxy resin, which is characterized in that carboxyl-containing polysiloxane functionalized aluminum nitride is used as a functionalized filler to fill and modify the epoxy resin, methyl tetrahydrophthalic anhydride is used as a curing agent, imidazole is used as an accelerant, and in the thermocuring process, the carboxyl-containing polysiloxane functionalized aluminum nitride modified epoxy resin is prepared. Carboxyl in a polysiloxane molecular chain grafted on the surface of the nano aluminum nitride reacts with an imidazole accelerant to generate imidazole carboxylate, an imidazole-carboxylic acid curing system is formed, the curing process of the epoxy resin can be accelerated, the nano aluminum nitride is uniformly dispersed in an epoxy resin matrix after being modified by the functionalized polysiloxane, the dispersity is good, and the curing effect is good. The heat conductivity coefficient and the thermal decomposition temperature of the epoxy resin are greatly improved, and the heat-conducting property and the heat-resisting property of the epoxy resin are enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy resins, in particular to a polysiloxane functionalized aluminum nitride modified epoxy resin and a preparation method thereof. Background Art

[0002] As a polymer material, epoxy resin can be used as a coating, adhesive, etc. due to its excellent electrical insulation, corrosion resistance, mechanical strength, etc., and is widely used in electronic appliances, mechanical manufacturing, etc., but epoxy resin has poor toughness. In recent years, mechanical toughening modification of epoxy resin has become a research hotspot. In addition, the thermal conductivity and heat resistance of traditional epoxy resin are not high, which limits the development and application of epoxy resin.

[0003] Nano-aluminum nitride has high resistivity and thermal conductivity, and is cheap, easy to obtain, high temperature resistant, and has good mechanical properties. Therefore, aluminum nitride can be used as a nano-filler and compounded with polymer materials. It has broad development prospects in the fields of electronic packaging and integrated circuits. CN102532606B "A modified aluminum nitride filled epoxy resin composite material" discloses aluminum nitride modified epoxy resin, which has good thermal conductivity and insulation. Therefore, nano-aluminum nitride can be compounded with epoxy resin to improve the thermal stability and heat resistance of epoxy resin.

[0004] 1. Technical issues to be resolved

[0005] In view of the deficiencies in the prior art, the present invention provides a polysiloxane functionalized aluminum nitride modified epoxy resin and a preparation method thereof, which enhance the thermal conductivity and heat resistance of the epoxy resin.

[0006] (II) Technical solution

[0007] To achieve the above object, the present invention provides the following technical solution: a polysiloxane functionalized aluminum nitride modified epoxy resin, the preparation method of the polysiloxane functionalized aluminum nitride modified epoxy resin is as follows: (1) Add 250-500 parts by weight of ethanol solvent, 100 parts by weight of nano-aluminum nitride and 2-8 parts by weight of aminopropyltriethoxysilane into a reaction container, treat at 60-80° C. for 2-6 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0008] (2) Add toluene solvent, amino-modified aluminum nitride, 1,2,4-trimellitic anhydride chloride and catalyst triethylamine into a reaction container, heat under reflux to react, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0009] (3) Add N,N-dimethylformamide solvent, anhydride-modified aluminum nitride, hydroxyl-terminated polydimethylsiloxane and catalyst 4-dimethylaminopyridine into a reaction container, heat to react, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol in turn to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0010] (4) Add polysiloxane functionalized aluminum nitride to epoxy resin E-44, disperse evenly, then add active diluent allyl glycidyl ether, curing agent methyltetrahydrophthalic anhydride and accelerator, stir evenly, pour the material into a mold, and cure at 65-90 °C for 4-6 h to obtain polysiloxane functionalized aluminum nitride modified epoxy resin.

[0011] Preferably, in step (2), the weight percentages of toluene solvent are 350-800 parts, amino-modified aluminum nitride is 100 parts, 1,2,4-trimellitic anhydride chloride is 35-65 parts, and catalyst triethylamine is 20-45 parts.

[0012] Preferably, the reaction temperature in step (2) is 40-70°C and the reaction time is 6-12 h.

[0013] Preferably, in step (3), the mass fractions of N,N-dimethylformamide are 800-2000 parts, the anhydride-modified aluminum nitride is 100 parts, the hydroxyl-terminated polydimethylsiloxane is 120-300 parts, and the 4-dimethylaminopyridine is 3.5-10 parts.

[0014] Preferably, the reaction temperature in step (3) is 35-55°C and the reaction time is 10-20 h.

[0015] Preferably, in step (4), the weight fraction of epoxy resin E-44 is 100 parts, the weight fraction of polysiloxane functionalized aluminum nitride is 5-20 parts, the weight fraction of allyl glycidyl ether is 12-20 parts, the weight fraction of methyltetrahydrophthalic anhydride is 45-65 parts, and the weight fraction of accelerator is 0.5-1.2 parts.

[0016] Preferably, the promoter in step (4) is any one of imidazole, 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0017] 3. Beneficial technical effects

[0018] Compared with the prior art, the present invention has the following beneficial technical effects: The invention discloses a polysiloxane functionalized aluminum nitride modified epoxy resin. The nano aluminum nitride is modified by aminopropyl triethoxysilane to introduce amino groups. Then, under the catalytic action of triethylamine, the amino groups react with the acyl chloride groups of 1,2,4-trimellitic anhydride acyl chloride to undergo amidation reaction, thereby introducing anhydride groups on the surface of the nano aluminum nitride to obtain anhydride modified aluminum nitride. The anhydride groups react with the terminal hydroxyl alkenyl anhydride of hydroxyl terminated polydimethylsiloxane to undergo esterification reaction to obtain polysiloxane functionalized aluminum nitride. At the same time, the anhydride ring is opened to generate ester groups and carboxyl groups, thereby grafting and introducing carboxyl-containing flexible polysiloxane on the surface of the nano aluminum nitride.

[0019] The polysiloxane functionalized aluminum nitride modified epoxy resin uses carboxyl-containing polysiloxane functionalized aluminum nitride as a functional filler to fill and modify the epoxy resin, uses methyltetrahydrophthalic anhydride as a curing agent, and imidazoles as accelerators. During the thermal curing process, the carboxyl groups in the polysiloxane molecular chains grafted on the surface of the nano-aluminum nitride react with the imidazole accelerators to generate imidazole carboxylates, thereby forming an imidazole-carboxylic acid curing system, which can accelerate the curing process of the epoxy resin. After being modified by the functionalized polysiloxane, the nano-aluminum nitride is uniformly dispersed in the epoxy resin matrix with good dispersibility, greatly improves the thermal conductivity and thermal decomposition temperature of the epoxy resin, and enhances the thermal conductivity and heat resistance of the epoxy resin. In addition, the flexible polysiloxane molecular chains grafted with the nano-aluminum nitride have good flexibility, form a cross-linking network with the epoxy resin, and improve the toughness of the epoxy resin. DETAILED DESCRIPTION

[0020] To achieve the above object, the present invention provides the following specific implementation methods and examples: A method for preparing a polysiloxane functionalized aluminum nitride modified epoxy resin is as follows: (1) Add 250-500 parts by weight of ethanol solvent, 100 parts by weight of nano-aluminum nitride and 2-8 parts by weight of aminopropyltriethoxysilane into a reaction container, treat at 60-80° C. for 2-6 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0021] (2) Add 350-800 parts by weight of toluene solvent, 100 parts by weight of amino-modified aluminum nitride, 35-65 parts by weight of 1,2,4-trimellitic anhydride chloride and 20-45 parts by weight of catalyst triethylamine into a reaction container, heat to 40-70°C, reflux for 6-12 hours, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0022] (3) Add 800-2000 parts by weight of N,N-dimethylformamide solvent, 100 parts of anhydride-modified aluminum nitride, 120-300 parts of hydroxyl-terminated polydimethylsiloxane and 3.5-10 parts of catalyst 4-dimethylaminopyridine into a reaction container, heat to 35-55 °C, react for 10-20 h, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol in turn to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0023] (4) Add 5-20 parts of polysiloxane functionalized aluminum nitride to 100 parts by weight of epoxy resin E-44, disperse evenly, then add 12-20 parts of active diluent allyl glycidyl ether, 45-65 parts of curing agent methyltetrahydrophthalic anhydride and accelerator, the accelerator is any one of imidazole, 2-methylimidazole and 2-ethyl-4-methylimidazole, stir evenly, pour the material into a mold, and cure at 65-90 °C for 4-6 h to obtain polysiloxane functionalized aluminum nitride modified epoxy resin. Example 1

[0024] (1) Add 35 mL of ethanol solvent, 10 g of nano-aluminum nitride and 0.2 g of aminopropyltriethoxysilane into a reaction container, treat at 60 °C for 2 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0025] (2) Add 25 mL of toluene solvent, 5 g of amino-modified aluminum nitride, 1.8 g of 1,2,4-trimellitic anhydride chloride and 1 g of catalyst triethylamine into a reaction container, heat to 40 °C, reflux for 6 h, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0026] (3) Add 45 mL of N,N-dimethylformamide solvent, 5 g of anhydride-modified aluminum nitride, 6 g of hydroxyl-terminated polydimethylsiloxane and 0.175 g of catalyst 4-dimethylaminopyridine into a reaction container, heat to 35 °C, react for 10 h, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol by centrifugation to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0027] (4) Add 0.5 g of polysiloxane-functionalized aluminum nitride to 10 g of epoxy resin E-44, disperse evenly, then add 1.2 g of active diluent allyl glycidyl ether, 4.5 g of curing agent methyltetrahydrophthalic anhydride and accelerator imidazole, stir evenly, pour the material into a mold, and cure at 65 °C for 4 h to obtain polysiloxane-functionalized aluminum nitride modified epoxy resin. Example 2

[0028] (1) Add 40 mL of ethanol solvent, 10 g of nano-aluminum nitride and 0.35 g of aminopropyltriethoxysilane into a reaction container, treat at 60 °C for 2 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0029] (2) Add 30 mL of toluene solvent, 5 g of amino-modified aluminum nitride, 2 g of 1,2,4-trimellitic anhydride chloride and 1.2 g of catalyst triethylamine into a reaction container, heat to 40 °C, reflux for 8 h, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0030] (3) Add 60 mL of N,N-dimethylformamide solvent, 5 g of anhydride-modified aluminum nitride, 8 g of hydroxyl-terminated polydimethylsiloxane and 0.25 g of catalyst 4-dimethylaminopyridine into a reaction container, heat to 40 °C, react for 10 h, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol in turn to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0031] (4) Add 0.8 g of polysiloxane-functionalized aluminum nitride to 10 g of epoxy resin E-44, disperse evenly, then add 1.5 g of active diluent allyl glycidyl ether, 5 g of curing agent methyltetrahydrophthalic anhydride and accelerator 2-methylimidazole, stir evenly, pour the material into a mold, and cure at 65 °C for 4 h to obtain polysiloxane-functionalized aluminum nitride modified epoxy resin. Example 3

[0032] (1) Add 45 mL of ethanol solvent, 10 g of nano-aluminum nitride and 0.5 g of aminopropyltriethoxysilane into a reaction container, treat at 70 °C for 4 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0033] (2) Add 35 mL of toluene solvent, 5 g of amino-modified aluminum nitride, 2.5 g of 1,2,4-trimellitic anhydride chloride and 1.6 g of catalyst triethylamine into a reaction container, heat to 60 °C, reflux for 10 h, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0034] (3) Add 70 mL of N,N-dimethylformamide solvent, 5 g of anhydride-modified aluminum nitride, 10 g of hydroxyl-terminated polydimethylsiloxane and 0.35 g of catalyst 4-dimethylaminopyridine into a reaction container, heat to 45 °C, react for 12 h, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol in turn to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0035] (4) Add 1.2 g of polysiloxane functionalized aluminum nitride to 10 g of epoxy resin E-44, disperse evenly, then add 1.6 g of active diluent allyl glycidyl ether, 5.5 g of curing agent methyltetrahydrophthalic anhydride and accelerator 2-methylimidazole, stir evenly and pour the material into a mold. Curing at 75 °C for 5 h to obtain polysiloxane functionalized aluminum nitride modified epoxy resin. Example 4

[0036] (1) Add 50 mL of ethanol solvent, 10 g of nano-aluminum nitride and 0.65 g of aminopropyltriethoxysilane into a reaction container, treat at 80 °C for 6 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0037] (2) Add 40 mL of toluene solvent, 5 g of amino-modified aluminum nitride, 2.5 g of 1,2,4-trimellitic anhydride chloride and 2 g of catalyst triethylamine into a reaction container, heat to 60 °C, reflux for 12 h, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0038] (3) Add 80 mL of N,N-dimethylformamide solvent, 5 g of anhydride-modified aluminum nitride, 12 g of hydroxyl-terminated polydimethylsiloxane and 0.4 g of catalyst 4-dimethylaminopyridine into a reaction container, heat to 45 °C, react for 15 h, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol by centrifugation to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0039] (4) Add 1.6 g of polysiloxane functionalized aluminum nitride to 10 g of epoxy resin E-44, disperse evenly, then add 1.8 g of active diluent allyl glycidyl ether, 6 g of curing agent methyltetrahydrophthalic anhydride and accelerator 2-methylimidazole, stir evenly and pour the material into a mold. Curing at 90 °C for 5 h to obtain polysiloxane functionalized aluminum nitride modified epoxy resin. Example 5

[0040] (1) Add 60 mL of ethanol solvent, 10 g of nano-aluminum nitride and 0.8 g of aminopropyltriethoxysilane into a reaction container, treat at 80 °C for 6 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0041] (2) Add 45 mL of toluene solvent, 5 g of amino-modified aluminum nitride, 3 g of 1,2,4-trimellitic anhydride chloride and 2.2 g of catalyst triethylamine into a reaction container, heat to 70 °C, reflux for 12 h, centrifuge, wash with ethanol and acetone and dry to obtain anhydride-modified aluminum nitride.

[0042] (3) Add 100 mL of N,N-dimethylformamide solvent, 5 g of anhydride-modified aluminum nitride, 15 g of hydroxyl-terminated polydimethylsiloxane and 0.5 g of catalyst 4-dimethylaminopyridine into a reaction container, heat to 55 °C, react for 20 h, then add deionized water, centrifuge, and wash with N,N-dimethylformamide and ethanol in turn to obtain carboxyl-containing polysiloxane functionalized aluminum nitride.

[0043] (4) Add 2 g of polysiloxane functionalized aluminum nitride to 10 g of epoxy resin E-44, disperse evenly, then add 2 g of active diluent allyl glycidyl ether, 6.5 g of curing agent methyltetrahydrophthalic anhydride and accelerator 2-ethyl-4-methylimidazole, stir evenly, pour the material into a mold, and cure at 90 °C for 6 h to obtain polysiloxane functionalized aluminum nitride modified epoxy resin.

[0044] Comparative Example 1 (1) Add 50 mL of ethanol solvent, 10 g of nano-aluminum nitride and 0.6 g of aminopropyltriethoxysilane into a reaction container, treat at 70 °C for 2 h, centrifuge, wash with ethanol and dry to obtain amino-modified aluminum nitride.

[0045] (4) Add 0.5 g of polysiloxane-functionalized aluminum nitride to 10 g of epoxy resin E-44, disperse evenly, then add 1.5 g of active diluent allyl glycidyl ether, 6.5 g of curing agent methyltetrahydrophthalic anhydride and accelerator imidazole, stir evenly, pour the material into a mold, and cure at 65 °C for 4 h to obtain polysiloxane-functionalized aluminum nitride modified epoxy resin.

[0046] The polysiloxane functionalized aluminum nitride modified epoxy resin and the aluminum nitride modified epoxy resin prepared in the examples and comparative examples were respectively made into standard samples with a specification of 100 mm×10 mm×3 mm, and the thermal conductivity of the standard samples was tested by a DRH-300 thermal conductivity tester according to GB / T 3399-1982 standard.

[0047] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Thermal conductivity (W / m·k) 0.298 0.365 0.488 0.604 0.651 0.215

[0048] The decomposition temperature of the modified epoxy resin standard sample was tested by Pyris-TGA thermogravimetric analyzer, and the maximum test temperature was 500 °C.

[0049] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Initial decomposition temperature (℃) 279.4 288.5 292.7 288.2 282.0 274.7 Complete decomposition temperature (℃) 415.2 418.6 420.8 422.7 415.7 411.8

Claims

1. A polysiloxane functionalized aluminum nitride modified epoxy resin, characterized in that: The preparation method of the polysiloxane functionalized aluminum nitride modified epoxy resin is as follows: (1) Adding 250-500 parts by weight of ethanol solvent, 100 parts by weight of nano-aluminum nitride and 2-8 parts by weight of aminopropyltriethoxysilane into a reaction container, treating at 60-80° C. for 2-6 hours, centrifuging, washing with ethanol and drying to obtain amino-modified aluminum nitride; (2) adding toluene solvent, amino-modified aluminum nitride, 1,2,4-trimellitic anhydride chloride and catalyst triethylamine into a reaction container, heating under reflux to react, centrifuging, washing with ethanol and acetone and drying to obtain anhydride-modified aluminum nitride; (3) adding N,N-dimethylformamide solvent, anhydride-modified aluminum nitride, hydroxyl-terminated polydimethylsiloxane and catalyst 4-dimethylaminopyridine into a reaction container, heating to react, then adding deionized water, centrifuging, and washing by N,N-dimethylformamide and ethanol centrifugation in sequence to obtain carboxyl-containing polysiloxane functionalized aluminum nitride; (4) Add polysiloxane functionalized aluminum nitride to epoxy resin E-44, disperse evenly, then add active diluent allyl glycidyl ether, curing agent methyltetrahydrophthalic anhydride and accelerator, stir evenly, pour the material into a mold, and cure at 65-90 °C for 4-6 h to obtain polysiloxane functionalized aluminum nitride modified epoxy resin.

2. A polysiloxane functionalized aluminum nitride modified epoxy resin according to claim 1, characterized in that: In the step (2), the weight percentages of toluene solvent are 350-800 parts, amino-modified aluminum nitride is 100 parts, 1,2,4-trimellitic anhydride chloride is 35-65 parts, and catalyst triethylamine is 20-45 parts.

3. A polysiloxane functionalized aluminum nitride modified epoxy resin according to claim 1, characterized in that: The reaction temperature in step (2) is 40-70°C and the reaction time is 6-12 h.

4. A polysiloxane functionalized aluminum nitride modified epoxy resin according to claim 1, characterized in that: In the step (3), the mass fractions of N,N-dimethylformamide are 800-2000 parts, the mass fractions of anhydride-modified aluminum nitride are 100 parts, the mass fractions of hydroxyl-terminated polydimethylsiloxane are 120-300 parts, and the mass fractions of 4-dimethylaminopyridine are 3.5-10 parts.

5. A polysiloxane functionalized aluminum nitride modified epoxy resin according to claim 1, characterized in that: The reaction temperature in step (3) is 35-55°C and the reaction time is 10-20 h.

6. A polysiloxane functionalized aluminum nitride modified epoxy resin according to claim 1, characterized in that: In the step (4), the weight percentage of epoxy resin E-44 is 100 parts, the weight percentage of polysiloxane functionalized aluminum nitride is 5-20 parts, the weight percentage of allyl glycidyl ether is 12-20 parts, the weight percentage of methyltetrahydrophthalic anhydride is 45-65 parts, and the weight percentage of accelerator is 0.5-1.2 parts.

7. The polysiloxane functionalized aluminum nitride modified epoxy resin according to claim 1, characterized in that: The accelerator in step (4) is any one of imidazole, 2-methylimidazole and 2-ethyl-4-methylimidazole.

8. A polysiloxane functionalized aluminum nitride modified epoxy resin prepared by the preparation method according to claims 1-7.

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