POLYMERIZATION OF PHENYLACETYLENES .6. CHAIN-TRANSFER REACTION IN POLYMERIZATIONS OF PHENYLACETYLENE AND STYRENE BY WCL6

Chain-transfer reactions to alkylbenzenes were investigated in the polymerizations of phenylacetylene and styrene by WCl//6 in benzene at 30 degree C. In the polymerization of phenylacetylene, alkylbenzenes did not work as chain-transfer agents, and further ethyl iodide was not a terminating agent. These findings suggest that the polymerization of phenylacetylene by WCl//6 differs from the conventional cationic or anionic mechanisms. On the other hand, the ability of alkylbenzenes as chain-transfer agents in the polymerization of styrene by WCl//6 increased in the following order: toluene less than p-xylene less than m-xylene less than o-xylene. This order is similar to that in the polymerization by SnCl//4. These results indicate that the polymerization of styrene by WCl//6 proceeds by a conventional cationic mechanism.