Radical copolymerization of vinylidene cyanide with 2,2,2-trifluoroethyl methacrylate: Structure and characterization

Abstract

A novel copolymer of vinylidene cyanide (VCN) and 2,2,2-trifluoroethyl methacrylate (MATRIF) was synthesized by bulk free radical process in a 52% yield from an equimolar comonomer feed. The copolymer's composition and microstruc- ture were analyzed by FTIR, 1 H- and 13 C-NMR spectroscopy, SEC, and elemental analysis. The reactivity ratios calculated from both the Q-e Alfrey-Price parameters and the Jenkins' Patterns Scheme indicate a tendency to alternation in the copolymerization, the latter method suggesting that MATRIF homopropagation be slightly favoured (rV ¼ r12 ¼ 0.1, rM ¼ r21 ¼ 0.3). The molar incorporation of VCN in the copolymer was only 42 mol % according to the 9.0 wt % nitrogen content deter- mined by elemental analysis, in good agreement with the value obtained by 1 H-NMR. High-resolution 1 Ha nd 13 C-NMR spectra were used to study the microstructure of the copolymer. As an example, the three well-resolved carbonyl resonances in the 13 C- NMR spectrum were assigned to the MATRIF-centered triads VMV, VMM, and MMM, respectively, (V and M stand for VCN and MATRIF, respectively). The presence of VCN dyads (e.g., in VVM and VVV sequences) was shown to be marginal or absent alto- gether. Thermogravimetric analysis of poly(VCN-co-MATRIF) co- polymer showed good thermal stability, and its main pyrolytic degradation taking place only above 368 � C. A 4% weight loss at about 222 � C suggested the presence of a few VCN homodyads, possibly inducing thermal depolymerization. V C 2010 Wiley Periodi- cals, Inc. J Polym Sci Part A: Polym Chem 48: 4900-4908, 2010