Design and synthesis of non-crystallizable, low-Tg polysiloxane elastomers with functional epoxy groups through anionic copolymerization and subsequent epoxidation

摘要: Although polysiloxane elastomers have many merits, their fast crystallization at low temperature is problematic in some fields. In this study, a novel non-crystallizable, low-Tg epoxidized (ESR) with functional epoxy groups side chains was designed and synthesized though two steps: (i) the preparation of poly(methylvinylsiloxane) (SR) by anionic ring-opening copolymerization 2,4,6,8-tetramethyl-2,4,6,8-tetravinyl cyclotetrasiloxane octamethylcyclotetrasiloxane, (ii) subsequent epoxidation SR. Reaction kinetic studies demonstrated that SR second-order reaction more than 90% double bonds were converted into during epoxidation. Despite slight increase Tg ESRs as content increased, low-temperature performances greatly improved because inhibition chains. Surprisingly, also showed higher thermal degradation temperatures traditional poly(dimethylsiloxane) did. The excellent performance high endowed ESR great potential an elastic material aerospace industry where materials to undergo very temperature.