Radiation-induced polymerization of acrylic acid in aqueous solution

Aqueous acrylic acid in the presence of cupric chloride has been subjected to γ-irradiation under various reaction conditions and the molecular weights of the resultant poly(acrylic acid) measured. The results, taken in conjunction with previous findings on the dependence of the rate of polymerization on intensity, monomer concentration, and cupric chloride concentration, indicate chain termination solely by cupric ion (rate constant k/sub tCu/) and chain transfer to polymer (rate constant k/sub f/). Values have been obtained for k/sub tCu//k/sub p/, k/sub f//k/sub p/ and G(radical) of acrylic acid. On the basis of these data a theoretical chain-length distribution has been derived which agrees well with distributions measured by gel-permeation chromatography