Phase transfer catalyzed single electron transfer–degenerative chain transfer mediated living radical polymerization (PTC‐SET–DTLRP) of vinyl chloride catalyzed by sodium dithionite and initiated with iodoform in water at 43 °C

Abstract

AbstractTo accelerate the living radical polymerization (LRP) of vinyl chloride (VC) in water the phase transfer catalyzed single electron transfer–degenerative chain transfer mediated living radical polymerization (SET–DTLRP) of VC mediated by sodium dithionite (Na2S2O4) was investigated. The fastest polymerization reaction that still produces thermally stable poly(vinyl chloride) (PVC) takes place at 43 °C with the ratio [PTC]0/[Na2S2O4]0 = 0.0075/1. Cetyltrimethylammonium bromide (nC16H33(CH3)3N+Br−, CetMe3NBr) was the phase‐transfer catalyst (PTC) of choice. Under these conditions the first, fast stage of SET–DTLRP of VC was accomplished within 7–8 h when the initial ratio monomer/initiator [VC]0/[CHI3]0 was 800. The number‐average molecular weight (Mn) of the resulting PVC was in good agreement with the theoretical molecular weight (Mth). When the [VC]0/[CHI3]0 ratio was 4800, the fast step of the reaction was accomplished within 17 h, to produce 72% monomer conversion. A deviation of the Mn from the Mth was observed in this case. Possible mechanistic explanations for this deviation as well as for the phase transfer catalyzed SET–DTLRP of VC were suggested. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 779–788, 2005