Novel Copolymers of Styrene and Some Ring-substituted 2-Phenyl-1,1-dicyanoethylenes

Novel copolymers of trisubstituted ethylenemonomers, ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC6H4CH = C(CN)2 (where R is 2-F, 2-CN, 3-CN, 4-CN, 3-C6H5O, 4-C6H5O, 2-C6H5CH2O, 3-C6H5CH2O, 4-C6H5CH2O, 4-CH3CO2, 4-CH3CONH, 4-(CH3)(2)N) and styrene were prepared 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, H-1 and C-13-NMR. The order of relative reactivity (1/r(1)) for themonomers is 4-(CH3)(2)N(3.35) >4-C6H5CH2O (3.1) >2-C6H5CH2O (1.77) >3-C6H5CH2O (1.72) >4-C6H5O (1.70) >4-CH3CO2 (1.58) >2-F (1.11) >3-C6H5O (0.90) >3-CN (0.88) >2-CN (0.86) > 4-CH3CONH (0.84) > 4-CN (0.76). Relatively high T-g 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 200-500 degrees C range with residue (1-10% wt), which then decomposed in the 500-800 degrees C range.