生胶结构对热硫化加成型硅橡胶力学性能的影响

Effect of Structure on Mechanical Properties of HTV Addition-type Silicone Rubber

研究了生胶结构中乙烯基摩尔分数、封端基团和苯基摩尔分数等对热硫化加成型硅橡胶力学性能的影响。结果表明,随着生胶中乙烯基摩尔分数的增加,硫化胶交联密度增大,硬度提高,拉断伸长率降低,拉伸强度和撕裂强度均先升后降;当生胶中乙烯基摩尔分数为0.15%~0.20%时,硫化胶加成硫化缺陷少,力学性能较好;相比甲基封端的生胶制成的硫化胶,乙烯基封端的生胶所制硫化胶的交联缺陷较少,力学性能更优;引入苯基能提高硫化胶的耐热老化性能和阻燃性能;采用不同乙烯基摩尔分数的生胶复配时,可形成集中交联,提高硫化胶的撕裂强度。

The effects of the vinyl content, capping groups and phenyl content of the structure on the me- chanical properties of addition - type high temperature vulcanized （HTV） silicone rubber were studied. Re- sults showed that with the increase of vinyl content in the rubber, the crosslink density and the hardness of HTV rubber increased, while the elongation at break decreased, and both the tensile strength and tear strength first rose and then fell. When the vinyl content of the rubber was between 0. 15% and 0. 20% , the HTV rub- ber had less crosslink defects and better mechanical properties. Compared with the methyl capping group, the HTV made from the crude rubber with vinyl capping group had less crosslink defects and better mechanical properties. The introduced phenyl group can enhance the thermal aging resistance and flame resistance. When introduced different vinyl content crude rubber to compound, they can centrally crosslinked and improve the tear strength of the HTV rubber.