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, 1H- and 13C-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=r12=0.1, rM=r21=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 1H-NMR. High-resolution 1H and 13C-NMR spectra were used to study the microstructure of the copolymer. As an example, the three well-resolved carbonyl resonances in the 13CNMR 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 C. A 4% weight loss at about 222 C suggested the presence of a few VCN homodyads, possibly inducing thermal depolymerization.
Radical Copolymerization of Vinylidene Cyanide with 2,2,2-Trifluoroethyl Methacrylate: Structure and Characterization
CASTELVETRO, VALTER;BIANCHI, SABRINA;
2010-01-01
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 microstructure were analyzed by FTIR, 1H- and 13C-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=r12=0.1, rM=r21=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 1H-NMR. High-resolution 1H and 13C-NMR spectra were used to study the microstructure of the copolymer. As an example, the three well-resolved carbonyl resonances in the 13CNMR 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 C. A 4% weight loss at about 222 C suggested the presence of a few VCN homodyads, possibly inducing thermal depolymerization.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
