Abstract: | The copolymerization of divinyl ether with fumaronitrile (A), tetracyanoethylene (B), and 4-vinylpyridine (C) has been studied, azobisisobutyronitrile being used as initiator. The compositions of the copolymers were calculated from their nitrogen and unsaturation content. Over a wide range of initial monomer composition, the mole fraction of A in the copolymers lies in the range 0.55–0.63, and the copolymers contained only 2–3% unsaturation, indicating a high degree of cyclization. The composition of the copolymers of B indicated that cyclization occurred to only a small extent, as the copolymers contained rather high unsaturation content. The values of r1 = 0.23 and r2 = 0.12 were obtained. The mole fraction of C in the copolymers lies between 0.85 and 0.998. If the assumption is made that r1 ? rc ? 0 and there is predominant cyclization, r2 = 32.0 in this case. The difference in the composition of the copolymers is attributed to the difference between the electron density of the double bonds in A, B, and C. |