화학공학소재연구정보센터
Journal of Polymer Science Part A: Polymer Chemistry, Vol.48, No.21, 4900-4908, 2010
Radical Copolymerization of Vinylidene Cyanide with 2,2,2-Trifluoroethyl Methacrylate: Structure and Characterization
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 microstructure were analyzed by FTIR, H-1- and C-13-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 (r(V) = r(12) = 0.1, r(M) = r(21) = 0.3). The molar incorporation of VCN in the copolymer was only 42 mol % according to the 9.0 wt % nitrogen content determined by elemental analysis, in good agreement with the value obtained by H-1-NMR. High-resolution H-1 and C-13-NMR spectra were used to study the microstructure of the copolymer. As an example, the three well-resolved carbonyl resonances in the C-13-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 altogether. Thermogravimetric analysis of poly(VCN-co-MATRIF) copolymer showed good thermal stability, and its main pyrolytic degradation taking place only above 368 degrees C. A 4% weight loss at about 222 degrees C suggested the presence of a few VCN homodyads, possibly inducing thermal depolymerization. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4900-4908, 2010