加成型导热固体氟硅橡胶的研制

Preparation of Addition-cure Thermally Conductive Solid Fluorosilicone Rubber

以甲基乙烯基氟硅橡胶为基料,以羟基硅油或二苯基硅二醇为结构控制剂,以2,5-二甲基-2,5-双(叔丁基过氧基)己烷为硫化剂,添加气相法白炭黑、导热填料制得加成型导热固体氟硅橡胶。探讨了填料品种、填料粒径、不同粒径氮化硅复配质量比等对加成型导热固体氟硅橡胶性能的影响。结果表明,当用量相同时,添加大粒径氮化物的导热氟硅橡胶的导热性能优于添加小粒径氮化物的导热氟硅橡胶,且各填料对胶料导热性能提高的大小为:氮化硅>氮化铝>氮化硼;当粒径7μm的氮化硅与粒径10μm的氮化硅复配质量比为1∶1时,制得的导热氟硅橡胶热导率最高,为1.362 W/(m·K);加入结构控制剂羟基硅油和二苯基硅二醇会降低胶料硬度和热导率,二次硫化对导热氟硅橡胶热导率影响不大。

The addition-cure thermally conductive solid fluorosilicone rubber was prepared with methyl vinyl fluorosilicone rubber as the base materials,and hydroxy silicone oil or diphenylsilyl glycol as the structure control agent,2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane as the vulcanizing agent,and fumed silica and a thermally conductive filler.The effect of the variety of fillers and particle size of the filler,the mass ratio of silicon nitride with different particle sizes on the properties of the fluorosilicone rubber was discussed.Results show that under the same content,the thermal conductivity of the fluorosilicone rubber with nitride(large particle size)is better than that of the fluorosilicone rubber with nitride(small particle size),and the thermal conductivity of each filler is improved as follows:nitrogen silicon>aluminum nitride>boron nitride.When the mass ratio of silicon nitride with 7μm of filler size to silicon nitride and that of 10μm of the particle size is 1:1,the rubber has the highest thermal conductivity rate of 1.362 W/(m·K).The addition of structural control agent of hydroxy silicone oil and diphenyl silicon diol will reduce the hardness and thermal conductivity of the rubber.The secondary vulcanization has little effect on the thermal conductivity of the fluorosilicone rubber.