耐高温硅橡胶的配方研究

为提高硅橡胶的耐高温性能，确定最佳的实验配方，以乙烯基硅橡胶为基础胶，八氢基笼型倍半硅氧烷(T8H8)为交联剂，白炭黑为补强填料，纳米级氧化锡为耐热填料，制备出一种耐高温硅橡胶.该配方中T8H8为自行合成的耐高温硅橡胶交联剂，通过红外光谱(FTIR)、X射线衍射(XRD)、核磁共振氢谱(1HNMR)对T8H8结构进行表征，探究了不同配方对硅橡胶耐热性能的影响.结果表明，当乙烯基硅油用量为100 phr，T8H8中Si—H与乙烯基硅橡胶中Si—Vi的摩尔比为4:1，白炭黑添加量为15 phr，氧化锡添加量为8 phr时，硅橡胶的初始分解温度达到489.77 ℃，拉伸强度为4.06 MPa，剪切强度1.69 MPa.
To improve the heat resistance of silicone rubber, and to determine the best experimental formula, a type of heat resistant silicone rubber was prepared, using polymethyl-vinyl siloxane rubber as basic gum, octahydridospherosiloxane (T8H8) as crosslink agent, silica as reinforcing filler, nano SnO2 as heat-resistant filler. In this formula, T8H8 was self-synthesized as heat resistant silicone rubber crosslniking agent. The structure was characterized by means of Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), i1HMR. The effect of different formula on heat resistant of rubber was studied. Results showed that when the amount of polymethyl-vinyl siloxane oil, the mass ratio of Si—H and Si—Vi, the amount of silica, and SnO2 was 100 phr, 4:1, 15 phr, and 8 phr, respectively, initial decomposition temperature of silicone rubber can reach 489.77 ℃, and its tensile strength and shear strength is 4.06 MPa, and 1.69 MPa.