Novel Copolymers of 4-Fluorostyrene. 4. Halogen Ring-Substituted 2-Phenyl-1,1-dicyanoethylenes

Novel copolymers of trisubstituted ethylene monomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H4CH=C(CN)2 (where R is 2-bromo, 3-bromo, 4-bromo, 2-chloro, 3-chloro, and 4-chloro) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70 degrees 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/r1) for the monomers is 3-chloro (1.8) 4-chloro (1.3) 2-chloro (1.2) 3-bromo (1.0) 4-bromo (0.9) 2-bromo (0.8). High Tg of the copolymers, in comparison with that of poly(4-fluorostyrene) indicates a substantial 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 280-400 degrees C range with residue, which then decomposition in 400-800 degrees C range.