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Kharas G.B.,ulUniversity | Delgado A.A.,ulUniversity | Gange N.,ulUniversity | Hartzell M.C.,ulUniversity | And 8 more authors.
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2013

Electrophilic trisubstituted ethylenes, oxy ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCHC(CN)CO2C2H 5, (where R is 3-ethoxy, 4-ethoxy, 4-propoxy, 4-butoxy, 4-hexyloxy, 3-phenoxy, 4-phenoxy, 3-(4-chlorophenoxy), 2-benzyloxy, 3-benzyloxy) were prepared and copolymerized with styrene. 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 styrene (M 1) in solution with radical initiation (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3-(4-chlorophenoxy) (1.82) > 3-phenoxy (1.14) > 4-phenoxy (0.91) > 3-ethoxy (0.66) > 2-benzyloxy (0.65) > 4-hexyloxy (0.42) > 4-propoxy (0.34) > 4-ethoxy (0.25) > 4-butoxy (0.20) > 3-benzyloxy (0.15). Relatively high 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 trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 250-500°C range with residue (3-8% wt), which then decomposed in the 500-800°C range. © 2013 Copyright Taylor and Francis Group, LLC. Source


Kharas G.B.,ulUniversity | Delgado A.A.,ulUniversity | Anderson N.E.,ulUniversity | Bajor A.,ulUniversity | And 10 more authors.
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry | Year: 2013

Electrophilic trisubstituted ethylenes, alkoxy ring-substituted ethyl 2-cyano-3-phenyl-2-propenoates, RPhCHC(CN)CO2C2H 5, (where 2,3-dimethoxy, 2,4-dimethoxy, 2,5-dimethoxy, 2,6-dimethoxy, 3,4-dimethoxy, 3,5-dimethoxy, 3-methyl-4-methoxy, 3-ethoxy-4-methoxy, 4-ethoxy-3-methoxy, 2,3,4-trimethyl, 2,4,5-trimethoxy, 2,4,6-trimethoxy, 3,4,5-trimethoxy) were prepared and copolymerized with styrene. 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 styrene (M1) in solution with radical initiation (ABCN) at 70°C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1H and 13C-NMR. The order of relative reactivity (1/r 1) for the monomers is 3,4,5-trimethoxy (0.42) > 2,3-dimethoxy (0.37) > 3-ethoxy-4-methoxy (0.36) > 2,4,5-trimethoxy (0.35) > 3,5-dimethoxy (0.25) > 3-methyl-4-methoxy (0.24) > 4-ethoxy-3-methoxy (0.23) > 2,4,6-trimethoxy (0.22) > 2,5-dimethoxy (0.19) = 3,4-dimethoxy (0.19) > 2,6-dimethoxy (0.18) > 2,4-dimethoxy (0.17) > 2,3,4-trimethyl (0.16). Relatively high 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 trisubstituted ethylene monomer unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 270-500°C range with residue (3-5% wt), which then decomposed in the 500-800°C range. © 2013 Copyright Taylor and Francis Group, LLC. Source

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