STUDIES ON CYCLO-COPOLYMERIZATION——COMPOSITION EQUATION AND REACTIVITY RATIOS OF SYMMETRICAL NONCONJUGATE DIENE AND VINYL MONOMER COPOLYMERIZATION

By considering characteristics of cyclo-copolymerization, the composition equation at low conversion was derived in the following form:where [M] and [B] represent the concentrations of diene and the vinyl monomer respectively, [M]cop and [B]cop the concentrations of diene and vinyl segment in the copolymer, and R1 and R2 represent the relative reactivity ratio of diene and vinyl monomer respectively. When [M] = [B], thenR1=2k11+2k1c/k12, Rs=k22/2k21+2kcc,R1 becomes the rate ratio of radical M·or m·attacking diene (including monomolecular and bimolecular mechanism) and vinyl monomer; and R2 becomes the rate ratio of radical B attacking vinyl monomer and diene (including two kinds of mechanism). By ap-pling the above equation, values of R1 and R2 for 12 sets of monomer pairs were obtained and found to be rather the best values with a permissible range of error.