Ladder-like polyphenylsilsesquioxane(LPPSQ)has been synthesized by a hydrolytic polycondensation reaction under alkaline conditions using phenyltrimethoxysilane(PTMS)as the raw material.LPPSQ modified room temperature vulcanized(RTV)silicone rubber was obtained after cross-linking and curing.The product was characterized by Fourier transform infrared spectroscopy,solid-state silicon-29 nuclear magnetic resonance spec-troscopy,and powder X-ray diffraction.The results showed that LPPSQ was synthesized successfully.The effect of LPPSQ on the properties of RTV silicone rubber was studied.It was found that LPPSQ can significantly improve the thermal stability and mechanical properties of RTV silicone rubber.Compared with traditional RTV silicone rubber,the elongation at break of RTV silicone rubber using LPPSQ as a crosslinking agent is more than two times higher,reaching 358%,and the toughness is significantly enhanced.In addition,in terms of thermal stability,LPPSQ also significantly increased the T10%and Tmax of RTV silicone rubber by 138.2 ℃ and 224.1 ℃,respec-tively.
关键词
梯形聚苯基倍半硅氧烷/室温硫化(RTV)/硅橡胶
Key words
ladder-like polyphenylsilsesquioxane/room temperature vulcanization/silicone rubber