乙烯基三乙氧基硅烷用量对液体硅橡胶性能的影响

以乙烯基硅油为原料，含乙烯基三乙氧基硅烷（A-151）就地处理过的气相法白炭黑为填料，制得高硬度、高强度加成型液体硅橡胶。研究了A-151的用量对加成型液体硅橡胶性能的影响。结果表明，A-151的用量能显著影响硅橡胶的硫化特性，随着A-151用量的增加，硅橡胶胶料的焦烧时间逐渐缩短，而正硫化时间则逐渐延长；硅橡胶的拉伸强度、撕裂强度、电气强度等先增后降，拉断伸长率降低、邵尔A硬度上升，胶料的起始黏度和黏度增长率上升，对硅橡胶的体积电阻率影响不大。当A-151的用量为1份时，硅橡胶的拉伸强度达最大值（8．8MPa）、撕裂强度为22．2kN／m、邵尔A硬度为50度、拉断伸长率为370％、电气强度为22．5kV／mm、体积电阻率为13．5×10^5Ω·cm，对硅橡胶的黏度和黏度增长率影响较小。

Effect of Vinyltriethoxysilane on the Properties of Liquid Silicone Rubber

Molding liquid silicone rubber with high hardness and strength was prepared using vinyl silicone oil as the raw material, fumed silica treated by vinyltriethoxysilane as the filler. The influence of the vi- nyltriethoxysilane on the performance of the molding liquid silicone rubber was studied. Results show that the content of vinyhriethoxysilane can significantly affect the vulcanization characteristics of the silicone rubber. With the increase of the amount of vinyhriethoxysilane, the scorch time of the silicone rubber gradually shortens, while the curing time gradually extended, and the tensile strength, tear strength, and electrical strength of vulcanized silicone rubber reach to a maximum and then decrease. There is no significant effect on the volume resistivity of the silicone rubber when the tensile elongation decreases, but the Shore A hardness and initial viscosity rate increases. With the loadings of vinyhriethoxysilane at 1 phr, the tensile strength of the silicone rubber reaches to the maximum value （8.8 MPa） with a tear strength of 22.2 kN/m, a Share A hardness of 50, a tensile elongation of 370%, an electric strength of 22.5 kV/mm, and a volume resistivity of 13. 5105 cm, with no significant effect on the viscosity and its growth rate.