Polymerization of styrene with diphenylzinc-cocatalyst systems

Summary The diphenylzinc-H₂O and diphenylzinc-H₂O-Bu^tCl systems were used as catalysts for styrene polymerization in solution at various temperatures and solvents. The systems are greatly influenced by the molar ratio H₂O/Ph₂Zn, and the maximum catalyst activity, in both cases, was found at a molar ratio of 0.75. GPC results strongly suggest the presence of more than one active species. For Ph₂Zn-H₂O-Bu^tCl system, in dichloromethane at-78°C with the molar ratio of H₂O/Ph₂Zn=0.75, the reaction is first order with respect to monomer with k_p=2.45×10^-3 Lmol^-1sec^-1.