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Electrophilic trisubstituted ethylene monomers, ring-substituted methyl 2-cyano-3-phenyl2-propenoates, RC6H4CH=C(CN)CO2 CH3 (where R = H, 2-CH3, 3-CH3, 4-CH3, 2-C2H5, 4-C2H5, 4-iC3H7, 4-C4H9 and 2,4,6-(CH3)3), were synthesized by the piperidine-catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and methyl cyanoacetate, and characterized by CHN elemental analysis, IR, 1H- and 13C-NMR. Co-polymerization of the propenoates and vinyl acetate in solution with radical initiation (AIBN) at 70°C yielded equimolar alternating co-polymers. The composition of the co-polymers was calculated from nitrogen analysis and the structures were analyzed by IR, 1H- and 13C-NMR, GPC, DSC and TGA. The high Tg of the co-polymers in comparison with that of polyvinyl acetate indicates a substantial decrease in chain mobility of the co-polymer due to the high dipolar character of the trisubstituted ethylene monomer unit. The gravimetric analysis indicated that the co-polymers decompose in the 214–400°C range. [ABSTRACT FROM AUTHOR]

Electrophilic trisubstituted ethylenes, ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RC6H4CH[dbnd]C(CN)CO2C2H5 (where R is 2-CH3, 3-CH3, 4-CH3, 2-OCH3, 3-OCH3, and 4-OCH3) were prepared and copolymerized with styrene (ST). The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C NMR. All the ethylenes were copolymerized with ST (M1) in solution with radical initiation (AIBN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1H and 13C NMR. The order of relative reactivity (1/r1) for the monomers is 3-OCH3 (0.88) > 4-CH3 (0.71) > 2-OCH3 (0.68) > 3-CH3 (0.55) > 2-CH3 (0.47) > 4-OCH3 (0.40). Higher Tg of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the TSE structural unit. Gravimetric analysis indicated that the copolymers decompose in the 257–287°C range. [ABSTRACT FROM AUTHOR]