High-temperature-resistant organic silicon polymer composite material and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant organic silicon polymer composite material and a preparation method thereof. The high-temperature-resistant organic silicon polymer composite material comprises the following raw materials in parts by weight: 100 parts of methyl phenyl silicone rubber; 2 to 4 parts of cerium dioxide; 1.2 to 1.8 parts of di-tert-butyl peroxide; 18 to 25 parts of fumed silica; 0.8 to 1.5 parts of a silane coupling agent; 30 to 40 parts of aluminum nitride; 1.5 to 2.2 parts of a titanate coupling agent; 6-10 parts of talcum powder; 15 to 20 parts of a disulfide bond modified organic silicon oligomer; 3 to 5 parts of nano titanium dioxide; 1.5 to 2.5 parts of dimethyl silicone oil; and 10-15 parts of aluminum hydroxide. According to the invention, through the synergistic effect of the methyl phenyl silicone rubber, the disulfide bond modified oligomer and aluminum nitride, the material can maintain mechanical properties (tensile strength and elasticity) and insulating property in a higher temperature environment, and can be applied to the fields with strict temperature resistance requirements, such as electronic and electrical appliances, aerospace and the like.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-molecular composite materials, and particularly relates to a high-temperature-resistant organic silicon high-molecular composite material and a preparation method thereof. BACKGROUND

[0002] The nanocomposite material has more excellent physical and mechanical properties than the conventional composite material due to the small size, large specific surface area, quantum effect and surface effect of the nanoparticles, and has unique properties in the aspects of electricity, magnetism, light, sound, thermodynamics, catalysis and biology.

[0003] The existing patent CN102352106B discloses an organic high-molecule-silica nanocomposite material and a preparation method thereof. The composite material is composed of silica and polylysine block copolymer. The morphology, size, surface polarity, solvent redispersibility and stability of the silica nanocomposite material can be controlled.

[0004] Although the existing technology realizes the preparation of the nanocomposite material, the functionality of the nanocomposite material is relatively poor. Therefore, the application provides a high-temperature-resistant organic silicon high-molecular composite material and a preparation method thereof. SUMMARY

[0005] The application aims to provide a high-temperature-resistant organic silicon high-molecular composite material and a preparation method thereof to solve the problems in the prior art.

[0006] To achieve the above object, the application provides the following technical scheme: a high-temperature-resistant organic silicon high-molecular composite material, which comprises the following raw materials in parts by weight:

[0007] methylphenyl silicone rubber 100 parts;

[0008] cerium dioxide 2-4 parts;

[0009] di-tert-butyl peroxide 1.2-1.8 parts;

[0010] fumed white carbon black 18-25 parts;

[0011] silane coupling agent 0.8-1.5 parts;

[0012] aluminum nitride 30-40 parts;

[0013] titanate coupling agent 1.5-2.2 parts;

[0014] talcum powder 6-10 parts;

[0015] double-sulfur-bond modified organic silicon oligomer 15-20 parts; nanometer titanium dioxide 3-5 parts;

[0016] dimethyl silicone oil 1.5-2.5 parts;

[0017] Aluminum hydroxide 10-15 parts.

[0018] Preferably, the raw materials include the following parts by weight: methyl phenyl silicone rubber 100 parts;

[0019] Cerium dioxide 3 parts;

[0020] Di-tert-butyl peroxide 1.5 parts;

[0021] Fumed white carbon black 22 parts;

[0022] Silane coupling agent 1.2 parts;

[0023] Aluminum nitride 35 parts;

[0024] Titanate coupling agent 1.8 parts;

[0025] Talc 8 parts;

[0026] Bisulfide bond modified organosilicon oligomer 18 parts; nano titanium dioxide 4 parts;

[0027] Dimethyl silicone oil 2 parts;

[0028] Aluminum hydroxide 12 parts.

[0029] Preferably, the aluminum nitride needs to be pretreated by a titanate coupling agent, the pretreatment temperature is 80-100℃, the treatment time is 1-2h, and the surface hydrophobicity of the modified aluminum nitride is ≥105°.

[0030] Preferably, the number average molecular weight of the bisulfide bond modified organosilicon oligomer is 5000-8000, and the bisulfide bond content is 0.8-1.2mmol / g.

[0031] Preferably, the specific surface area of the fumed white carbon black is 200-300m 2 / g, and after modification by the silane coupling agent KH-560, the surface hydroxyl content is ≤0.5mmol / g.

[0032] A preparation method of a high temperature resistant organosilicon polymer composite material, comprising the following steps:

[0033] S1, raw material pretreatment: modify the aluminum nitride with a titanate coupling agent at 80-110℃ for 90-130min, modify the fumed white carbon black with a silane coupling agent at 110-120℃ and a vacuum degree of-0.08--0.09MPa for 60-90min, and dry the nano titanium dioxide after ultrasonic dispersion and silane coupling agent modification;

[0034] S2, segment mixing: 100 parts of methyl phenyl silicone rubber is plasticized at 80-90℃ for 5-8min, the pretreated fumed white carbon black, talc, nano titanium dioxide is added and stirred for 15-20min; the temperature is raised to 120-130℃, the pretreated aluminum nitride, dimethyl silicone oil is added and stirred for 10-15min, then the disulfide bond modified silicone oligomer is added and stirred for 8-12min; the temperature is lowered to 60-70℃, the cerium dioxide, aluminum hydroxide, di-t-butyl peroxide is added and stirred for 5-8min, and the mixing rubber is discharged;

[0035] S3, gradient vulcanization: vulcanization at 150-160℃, 10-15MPa for 10-15min; the temperature is raised to 170-180℃, 10-15MPa is maintained for 20-25min; the temperature is lowered to 120-130℃, 5-8MPa, and curing for 30-40min;

[0036] S4, post-processing: the vulcanized product is dried at 100-110℃ for 120-180min, and the finished product is obtained after cooling.

[0037] Preferably, in S1, the amount of titanate coupling agent is 4-6% of the mass of aluminum nitride, and the amount of silane coupling agent is 4-6% of the mass of fumed white carbon black.

[0038] Preferably, in S1, the power of ultrasonic dispersion of nano titanium dioxide is 300-400W, and the time is 20-30min.

[0039] Preferably, in S2, the speed of the internal mixer is 50-60r / min in the low-temperature dispersion stage and 70-80r / min in the high-temperature mixing stage.

[0040] Preferably, in S3, the total crosslinking density of gradient vulcanization is 1.4-1.6mmol / g, and the disulfide bond content is 0.8-1.2mmol / g.

[0041] Compared with the prior art, the beneficial effects of the present application are:

[0042] 1. Through the synergistic effect of methyl phenyl silicone rubber, disulfide bond modified oligomer and aluminum nitride, the material can maintain mechanical properties (tensile strength, elasticity) and insulation performance at higher temperature environment, and can be applied to electronic appliances, aerospace and other fields with strict requirements on temperature resistance.

[0043] 2. The reinforcing effect of fumed white carbon black combined with dynamic crosslinking of disulfide bond makes the material maintain tensile strength retention rate ≥80% and tear strength retention rate ≥75% at 200℃ high temperature, avoiding the problem of "brittleness and easy fracture" of the material at high temperature; at the same time, the addition of talc can reduce the shrinkage rate of the material and improve the dimensional stability.

[0044] 3. The rotational speed and temperature control of the segmented mixing avoids the agglomeration and failure of raw materials, and the flowability of the mixed rubber is more uniform, which can be adapted to various processing methods such as molding and extrusion; and the stress release process of gradient vulcanization reduces the defects such as warping and cracking of the product.

[0045] 4. The aluminum hydroxide decomposes endothermically at high temperature and releases water vapor, which can dilute combustible gases and block oxygen, so that the material meets the UL94V-0 level of flame retardant standard and is suitable for the fireproof requirements of electronic equipment; the nano titanium dioxide can absorb ultraviolet rays to reduce the aging speed of the material in outdoor or strong ultraviolet environment, thereby prolonging the service life; the high thermal conductivity of aluminum nitride increases the thermal conductivity of the material to 1.5-2.0 W / (m·K), which can be used for high-temperature parts that need heat dissipation, realizing the dual functions of 'temperature resistance and heat conduction'. BRIEF DESCRIPTION OF DRAWINGS

[0046] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate embodiments of the present application and explain the present application together with the embodiments of the present application, and do not constitute a limitation of the present application. In the drawings:

[0047] Figure 1 is a flowchart of the present application. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only to represent selected embodiments of the present application.

[0049] Please refer to Figure 1 In the embodiments of the present application, a high-temperature-resistant organic silicon polymer composite material includes the following raw materials by weight:

[0050] Methylphenyl silicone rubber 100 parts;

[0051] Cerium dioxide 2-4 parts;

[0052] Di-tert-butyl peroxide 1.2-1.8 parts;

[0053] Fumed white carbon black 18-25 parts;

[0054] Silane coupling agent 0.8-1.5 parts;

[0055] Aluminum nitride 30-40 parts;

[0056] Titanate coupling agent 1.5-2.2 parts;

[0057] Talc 6-10 parts;

[0058] Disulfide bond modified organosilicon oligomer 15-20 parts;

[0059] Nano titanium dioxide 3-5 parts;

[0060] Dimethyl silicone oil 1.5-2.5 parts;

[0061] Aluminum hydroxide 10-15 parts.

[0062] Preferably, the raw materials specifically include the following parts by weight:

[0063] Methyl phenyl silicone rubber 100 parts;

[0064] Cerium dioxide 3 parts;

[0065] Di-tert-butyl peroxide 1.5 parts;

[0066] Fumed white carbon black 22 parts;

[0067] Silane coupling agent 1.2 parts;

[0068] Aluminum nitride 35 parts;

[0069] Titanate coupling agent 1.8 parts;

[0070] Talc 8 parts;

[0071] Disulfide bond modified organosilicon oligomer 18 parts;

[0072] Nano titanium dioxide 4 parts;

[0073] Dimethyl silicone oil 2 parts;

[0074] Aluminum hydroxide 12 parts.

[0075] Preferably, the aluminum nitride needs to be pretreated by a titanate coupling agent, the pretreatment temperature is 80-100℃, the treatment time is 1-2h, and the surface hydrophobicity of the modified aluminum nitride is ≥105°.

[0076] Preferably, the number average molecular weight of the disulfide bond modified organosilicon oligomer is 5000-8000, and the disulfide bond content is 0.8-1.2mmol / g.

[0077] Preferably, the specific surface area of the fumed white carbon black is 200-300m 2 / g, and after modification by silane coupling agent KH-560, the surface hydroxyl content is ≤0.5mmol / g.

[0078] A preparation method of a high-temperature-resistant organic silicon polymer composite material, comprising the following steps:

[0079] S1, raw material pretreatment: modify the aluminum nitride with titanate coupling agent at 80-110 DEG C for 90-130 min, modify the fumed white carbon black with silane coupling agent at 110-120 DEG C and a vacuum degree of-0.08 to-0.09 MPa for 60-90 min, and dry the nano-titanium dioxide after ultrasonic dispersion and silane coupling agent modification; the amount of titanate coupling agent is 4-6% of the mass of aluminum nitride, and the amount of silane coupling agent is 4-6% of the mass of fumed white carbon black; the power of ultrasonic dispersion of nano-titanium dioxide is 300-400 W, and the time is 20-30 min;

[0080] S2, subsection mixing: plasticize 100 parts of methylphenyl silicone rubber at 80-90 DEG C for 5-8 min, add the pretreated fumed white carbon black, talcum powder and nano-titanium dioxide, and stir for 15-20 min; heat to 120-130 DEG C, add the pretreated aluminum nitride and dimethyl silicone oil, stir for 10-15 min, then add the disulfide bond modified silicone oligomer, and stir for 8-12 min; cool to 60-70 DEG C, add cerium dioxide, aluminum hydroxide and di-tert-butyl peroxide, stir for 5-8 min, and discharge to form a mixed rubber; the speed of the internal mixer is 50-60 r / min in the low-temperature dispersion stage and 70-80 r / min in the high-temperature mixing stage;

[0081] S3, gradient vulcanization: vulcanize at 150-160 DEG C and 10-15 MPa for 10-15 min; heat to 170-180 DEG C, keep 10-15 MPa for 20-25 min; cool to 120-130 DEG C and 5-8 MPa for 30-40 min; the total crosslinking density of gradient vulcanization is 1.4-1.6 mmol / g, and the disulfide bond content is 0.8-1.2 mmol / g;

[0082] S4, post-treatment: dry the vulcanized product at 100-110 DEG C for 120-180 min, and obtain the finished product after cooling.

[0083] The working principle of the present application is that the methylphenyl silicone rubber as the core base material can significantly improve the high-temperature stability of the silicone rubber due to the phenyl groups contained in the molecular chain; and the disulfide bond modified silicone oligomer can form a crosslinked network with the molecular chain of the methylphenyl silicone rubber; the disulfide bond can slowly break and recombine at high temperature, which not only avoids the direct embrittlement of the material due to high temperature, but also supplements the bond energy loss in the heat aging process through dynamic crosslinking, thereby prolonging the performance retention time at high temperature.

[0084] The aluminum nitride is not only excellent in high temperature resistance, but also can be combined with the silicone base material closely through the "bridge effect" of the titanate coupling agent, so that the difference in thermal expansion between the filler and the base material interface at high temperature is reduced, and the interface cracking is avoided. Meanwhile, the high thermal conductivity of the aluminum nitride can quickly conduct the local heat generated in the material due to high temperature, and reduce the thermal stress concentration.

[0085] The fumed white carbon black forms physical entanglement with the silicone molecular chain through high specific surface area, so that the tensile strength and tear strength of the material are improved. The silane coupling agent modification can eliminate the hydrophilic hydroxyl on the surface of the white carbon black, avoid the degradation reaction of the hydroxyl and the silicone at high temperature, and further enhance the temperature resistance.

[0086] Finally, it should be pointed out that: the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing embodiments of the present application are described in detail, for those skilled in the art, it still can be modified, or the equivalent replacement of part of the technical features recorded in the foregoing embodiments. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high heat resistant silicone polymer composite, characterized by, The raw materials include the following weight parts: Methyl phenyl silicone rubber 100 parts; Cerium dioxide 2-4 parts; Di-tert-butyl peroxide 1.2-1.8 parts; Fumed white carbon black 18-25 parts; Silane coupling agent 0.8-1.5 parts; Aluminum nitride 30-40 parts; Titanate coupling agent 1.5-2.2 parts; Talc powder 6-10 parts; Disulfide bond modified silicone oligomer 15-20 parts; Nano titanium dioxide 3-5 parts; Dimethyl silicone oil 1.5-2.5 parts; Aluminum hydroxide 10-15 parts.

2. The high temperature resistant silicone polymer composite according to claim 1, characterized in that, The raw materials include the following weight parts: Methyl phenyl silicone rubber 100 parts; Cerium dioxide 3 parts; Di-tert-butyl peroxide 1.5 parts; Fumed white carbon black 22 parts; Silane coupling agent 1.2 parts; Aluminum nitride 35 parts; Titanate coupling agent 1.8 parts; Talc powder 8 parts; Disulfide bond modified silicone oligomer 18 parts; Nano titanium dioxide 4 parts; Dimethyl silicone oil 2 parts; Aluminum hydroxide 12 parts.

3. The high temperature resistant silicone polymer composite according to claim 1, characterized in that, The aluminum nitride needs to be pretreated by modification with a titanate coupling agent, the pretreatment temperature is 80-100℃, the treatment time is 1-2h, and the surface hydrophobicity of the modified aluminum nitride is ≥105°.

4. The high temperature resistant silicone polymer composite according to claim 1, characterized in that, The number average molecular weight of the disulfide bond modified silicone oligomer is 5000-8000, and the disulfide bond content is 0.8-1.2mmol / g.

5. The high temperature resistant silicone polymer composite according to claim 1, characterized in that, The specific surface area of the fumed white carbon black is 200-300 m 2 / g, and after modification by a silane coupling agent KH-560, the surface hydroxyl content is ≤0.5 mmol / g.

6. The preparation method of the high-temperature-resistant silicone polymer composite according to any one of claims 1-5, characterized in that, The steps include: S1, raw material pretreatment: the aluminum nitride is modified with a titanate coupling agent at 80-110℃ for 90-130min, the fumed white carbon black is modified with a silane coupling agent at 110-120℃ and a vacuum degree of-0.08--0.09MPa for 60-90min, and the nano titanium dioxide is dried after ultrasonic dispersion and modification with a silane coupling agent; S2, stepwise mixing: 100 parts of methyl phenyl silicone rubber is plasticized at 80-90℃ for 5-8min, and the pretreated fumed white carbon black, talc powder, and nano titanium dioxide are added and stirred for 15-20min; The temperature is raised to 120-130℃, the pretreated aluminum nitride, dimethyl silicone oil is added, and stirred for 10-15min, then the disulfide bond modified silicone oligomer is added, and stirred for 8-12min; the temperature is lowered to 60-70℃, and the cerium dioxide, aluminum hydroxide, and di-tert-butyl peroxide are added, and stirred for 5-8min, then the product is discharged to form a mixed rubber; S3, gradient vulcanization: vulcanization is carried out at 150-160℃ and 10-15MPa for 10-15min; the temperature is raised to 170-180℃, and maintained at 10-15MPa for 20-25min; the temperature is lowered to 120-130℃, and 5-8MPa for 30-40min; S4, post-treatment: the vulcanized product is dried at 100-110℃ for 120-180min, and the finished product is obtained after cooling.

7. The preparation method of high temperature resistant silicone polymer composite according to claim 6, characterized in that, In S1, the amount of titanate coupling agent is 4-6% of the mass of aluminum nitride, and the amount of silane coupling agent is 4-6% of the mass of fumed white carbon black. 8.The method for preparing a high-temperature-resistant silicone polymer composite according to claim 6, characterized in that, In S1, the power for ultrasonic dispersion of nano titanium dioxide is 300-400W, and the time is 20-30min.

9. The preparation method of high temperature resistant silicone polymer composite according to claim 6, characterized in that, In S2, the rotating speed of the internal mixer is 50-60r / min in the low temperature dispersion stage, and 70-80r / min in the high temperature mixing stage.

10. The method according to claim 6, wherein the high temperature resistant silicone polymer composite is prepared by the following steps: 1) mixing the silicone polymer, the inorganic filler, the organic filler, the coupling agent, and the antioxidant to obtain a mixture; 2) heating the mixture to obtain a high temperature resistant silicone polymer composite. The total crosslinking density of the gradient vulcanization in the S3 is 1.4-1.6 mmol / g, and the disulfide bond content is 0.8-1.2 mmol / g.

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