文献类型：期刊文献

英文题名：Effect of silanol on the thermal stability of poly[methyl(trifluoropropyl)siloxane]

作者：You, Yang[1];Chen, Jianding[1];Zheng, Anna[1];Wei, Dafu[1];Xu, Xiang[1];Guan, Yong[1]

机构：[1]East China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai Key Lab Adv Polymer Mat, Shanghai 200237, Peoples R China

年份：2020

卷号：137

期号：44

外文期刊名：JOURNAL OF APPLIED POLYMER SCIENCE

收录：;EI(收录号：20201908620061);WOS:【SCI-EXPANDED(收录号:WOS:000529852500001)】；

基金：Fundamental Research Funds for the Central Universities, Grant/Award Number: 222201914004; National Natural Science Foundation of China, Grant/Award Numbers: 51573043, 21805086; Shanghai Key Laboratory Project, Grant/Award Number: ZD20170203; Shanghai Leading Academic Discipline Project, Grant/Award Number: B502

语种：英文

外文关键词：elastomers; rubber; thermal properties; thermogravimetric analysis

摘要：Poly[methyl(trifluoropropyl)siloxane] (PMTFPS), which is an essential polymer in oil-resistant rubber materials, exhibits unsatisfactory thermal stability. In this article, PMTFPSs with methyl and hydroxyl terminal groups are prepared, and their thermal stabilities are investigated via thermogravimetric analysis and pyrolysis-gas chromatography-mass spectrometry in an inert atmosphere. Additionally, the degradation mechanisms are discussed in terms of molecular structural characteristics (bond length and bond angle) and reaction driven forces (electrostatic potential and atom charge) based on quantum chemistry calculations. PMTFPS is found to degrade mainly into cyclic monomers through (a) the Si-O rearrangement reaction in the middle of the chain and (b) the "back-biting" reaction from the end of the chain. PMTFPS with silanol terminal groups is more likely to degrade according to pathway (b), resulting in more cyclotrisiloxane. Furthermore, the silanol from nano-silica accelerates the degradation of PMTFPS, and the mechanism of this process is presented.