Radiation‐induced emulsion polymerization of ethylene. III. Emulsion polymerization with ammonium perfluorooctanoate as the emulsifier

Radiation‐induced emulsion polymerization of ethylene with ammonium perfluoro‐octanoate as an emulsifier was studied in order to elucidate the effect of the number of polymer particles. Owing to the stable structure of the emulsifier from a radical attack, no CF bond was detected in the polyethylene as expected. The polyethylene produced was mostly gel containing a small amount of low molecular weight polyethylene. This may be attributable to chain transfer to the polyethylene. The effects of dose rate and of concentration of the emulsifier were determined without considering the chain‐transfer reaction to the emulsifier. By considering the escape of the radical which is produced by chain transfer to the monomer from the polymer particle to the aqueous phase at the steady state, the following equation is derived: The experimental results could be explained by this equation, and the apparent rate constants were obtained.