Characterization of Butadiene-Acrylonitrile Emulsion Copolymers by Nuclear Magnetic Resonance
Recently, the synthesis and nuclear magnetic resonance (NMR) spectra of completely alternating butadiene-acrylonitrile (B-A) copolymers have been reported (1),(2). The completely alternating copolymer was shown to have some improved physical properties over an emulsion copolymer of similar monomer composition (3). In an extensive study of B-A emulsion copolymers at 5°C(4), two sets of reactivity ratios were derived: rB = 0.28 and rA = 0.02; and rB = 0.18 and rA = 0.03. The latter set takes into account the difference in solubility of the acrylonitrile monomer in the oil and water phases. In either case, r1r2,<<1 and the emulsion copolymers should be highly alternate.
KeywordsChloroform Nitrile Triad Diene Copolymerization
Unable to display preview. Download preview PDF.