Polymerization of vinyl chloride in the presence of different solvents

The polymerization of vinyl chloride in tetrahydrofuran, 1.2‐dichloroethane and chlorobenzene with lauroyl peroxide as initiator has been studied. In these solvents the polymerizing systems separate in two phases at a certain degree of conversion which is a fanction of the initial monomer concentration. In relation with the phase separation a decrease of the polymerization rates occurs. For the homogeneous polymerization the reaction order with respect to monomer is 1 in tetrahydrofuran and 1.2‐dichloroethane. In the polymerization in chlorobenzene the solvent acts as a retarder and consequently it is impossible to determine the reaction order with respect to monomer. The reaction order with respect to initiator is found to be 0.35 in all the examined solvents. In the solvents which are not high chain transfer agents, the molecular weights of the polymers vary with the monomer concentration in the same manner as the polmerization rate. The tetrahydrofuran is found to be a very active chain transfer agent. An interpretation of the experimental data is given.