交联聚硅氧烷的热降解行为

The Pyrolysis Behavior of Cross-linked Polysiloxanes

运用TGA—IR研究了交联聚二甲基硅氧烷以及含 10 %、16%苯基硅氧烷链段的聚二甲基硅氧烷的热降解行为 ,并用FTIR分析了聚硅氧烷的热分解产物。结果表明 ,在 30 0℃以上 ,交联聚硅氧烷热降解的主要产物为环三硅氧烷和环四硅氧烷 ,裂解反应既在分子链内发生也在分子链间发生。在惰性气氛下 。

The pyrolytic behavior and pyrolytic products of cross linked polysiloxanes, including polydimethylsiloxane and polydimethylsiloxane blocked with 10% and 16% polydiphenylsiloxane segments are studied by TGA IR technique. Experimental results show that the main pyrolytic products of polysiloxane above 300℃ in nitrogen atmosphere is hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4). The pyrolysis reaction occurrs both in intermolecular chains and intramolecular chains. Thermal stability of polysiloxane in inert gas atmosphere can not be improved by introduction of diphenylsiloxane segments.