The production of poly(3,3,3-trifluoropropyl)methylsiloxane (PTFPMS), a pivotal polymer in the development of oil-resistant rubber, is hindered by the challenging issue of backbiting during synthesis. In this study, PTFPMS with low dispersity (1.16) and a molar mass around 10,000 g·mol–1 was synthesized via anionic ring-opening polymerization (AROP) initiated by diphenylsilanediol and catalyzed by 1,5,7-triazabicyclo4.4.0dec-5-ene (TBD). Apparent propagation and backbiting rates were calculated from the study of the polymerization kinetics. This article shows that backbiting occurs from the beginning of polymerization for homopolymerization before reaching an equilibrium at around 80% conversion of F3 ((3,3,3-trifluoropropyl)methylcyclotrisiloxane). Copolymerizations of F3 and V3 (1,3,5-trivinyl-1,3,5-trimethylcyclotrisiloxane) were carried out to determine the reactivity ratios of these monomers (rF3 = 6.42 and rV3 = 0.72). The addition of the V3 comonomer has been demonstrated to effectively inhibit the depolymerization of PTFPMS.
Corfa et al. (Tue,) studied this question.