Polymerization of phenylacetylenes. VI. Chain‐transfer reaction in the polymerizations of phenylacetylene and styrene by WCl₆

Abstract

Abstract Chain‐transfer reactions to alkylbenzenes were investigated in the polymerizations of phenylacetylene and styrene by WCl 6 in benzene at 30°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 < p ‐xylene < m ‐xylene < 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.