Effect of diphenylbutadiyne on the free radical polymerization of vinyl monomers in solution

The free radical polymerization of vinyl monomers such as styrene, methylmethacrylate, methyacrylate, acrylonitrile, vinylacetate, etc. in the presence of diphenylbutadiyne, was investigated. Both rates of polymerization and molecular weights of polymer decreased by the addition of diphenylbutadiyne. The degree of retardation depended on the stability of propagating radicals. The butadiyne does not react with the propagating radicals having high Q values, but it seems to trap the radicals temporarily thus retarding the polymerization