Bulk and solution polymerization of vinyl‐monomers in the presence of a chain transfer agent. Part I. vinyl chloride

The effect of carbon tetrabromide transfer both in bulk and 1.2‐dichloroethane solution polymerization of vinyl chloride has been investigated at 50°C. In heterogeneous systems the presence of carbon tetrabromide rises the initial polymerization rate, but reduces or eliminates, respectively, the autocatalysis of the reaction. On the other hand, in homogeneous systems, carbon tetrabromide exhibits a weak retarding action. In both homogeneous and heterogeneous polymerization, carbon tetrabromide has a strong effect as chain transfer agent and its transfer constant deduced from the molecular weight of the polymers obtained in homogeneous systems is 4.70. The results are discussed based on a model recently proposed by the authors.