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Novel copolymers of trisubstituted ethylene monomers, alkyl ring-substituted 2-phenyl-1,1-dicyanoethylenes, RC 6 H 4 CH=C(CN) 2 (where R is 2-methyl, 3-methyl, 4-methyl, 4-ethyl, 4-i -propyl, 4-butyl, 4-i -butyl, and 4-t-butyl) and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70 • C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1 H and 13 C-NMR. The order of relative reactivity (1/r 1 ) for the monomers is 4-ethyl (42.6) > 4-butyl (29.4) > 4-t-butyl (26.7) > 4-i -butyl (1.6) > 4-i -propyl (1.29) > 3-methyl (1.26) > 2-methyl (0.8) > 4-methyl (0.4). High T g 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 183-500 • C range with residue (5-30% wt.), which then decomposed in the 500-800 • C range.

5 O), were prepared and copolymerized with styrene. The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and N-cyanoacetylurethane, and characterized by CHN analysis, IR, 1 H-and 13 C-NMR. All the ethylenes were copolymerized with styrene (M 1 ) in solution with radical initiation (ABCN) at 70 • C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, 1 H-and 13 C-NMR. The order of relative reactivity (1/r 1 ) for the monomers is 3-C 2 H 5 O (2.1) > 4-CH 3 (CH 2 ) 3 (1.7) > 2-C 2 H 5 O (1.5) ≈ 4-CH 3 CH 2 (1.5) > 4-CH 3 (CH 2 ) 2 O (0.9) > 2,5-(CH 3 ) 2 (0.5) ≈ 4-CH 3 (CH 2 ) 3 O (0.5) > 2,4-(CH 3 ) 2 (0.4) > 4-CH 3 (CH 2 ) 4 O (0.3) ≈ 4-(CH 3 ) 2 CH (0.3). High T g of the copolymers, in comparison with that of polystyrene, indicates decrease in chain mobility of the copolymer due to the high dipolar character of the trisubstituted ethylene structural unit. Decomposition of the copolymers in nitrogen occurred in two steps, first in 270-420 • C with a residue (3-10% wt), which then decomposed in the 550-700 • C range.

and 4-fluorostyrene were prepared at equimolar monomer feed composition by solution copolymerization in the presence of a radical initiator (ABCN) at 70 • C. The composition of the copolymers was calculated from nitrogen analysis, and the structures were analyzed by IR, 1 H and 13 C-NMR. The order of relative reactivity (1/r 1 ) for the monomers is 3,4,5-(CH 3 O) 3 (10.6) > 2,4,6-(CH 3 O) 3 (9.3) > 2,4,5-(CH 3 O) 3 (5.4) > 2,3,4-(CH 3 O) 3 (4.4) > 6-Br-3,4-(CH 3 O) 2 (3.2) > 2,3,5-Cl 3 (1.5) > 2,3,6-Cl 3 (1.0) > 2,4-(CH 3 O) 2 -3-CH 3 (0.7). High T g 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 200-400 • C range with residue, which then decomposed in the 400-800 • C range.