ALTERNATING COPOLYMERIZATION OF ALPHA-METHYLSTYRENE AND MALEIC-ANHYDRIDE

In the reported experiments, alternating copolymers of alpha -methylstyrene ( alpha -MeSt) and maleic anhydride (MAn) were prepared by free-radical-initiated polymerization in bulk, benzene, or butanone as solvents. By applying the generalized model described by Shirota and co-workers, the reactivity ratios k//1//c/k//1//2 and k//2//c/k//2//1 were calculated from the change of copolymerization rate with monomer feed at constant total monomer concentration. From the equation R//p equals R//p(f) plus R//p(CT) were calculated R//p(f) and R//p(CT), and it was found that in benzene the reaction proceeds predominantly by the addition of CT-complex monomers, while in butanone, cross propagation of free monomers predominates. Termination occurs predominantly by homotermination of alpha -MeSt macro free radicals, k//t//2//2, although the cross termination k//t//2//1 is also operative.