The kinetics of radiation graft polymerization of acrylic acid from the gas phase on kaolin

Abstract

The main kinetic relationships of radiation graft polymerization of acrylic acid on kaolin under different reaction conditions (temperature, monomer vapour pressure, concentration of adsorbed monomer and dose rate), are investigated. The dependence of polymerization rate on dose rate is of an unusual type, both the initial rate and the rate of polymerization on a grafted layer of poly(acrylic acid) are directly proportional to dose rate. It is suggested that this unusual feature is explained by the unusually compact structure of the grafted poly(acrylic acid). After loosening of the grafted polymer layer by treatment with ammonia or successively with ammonia and hydrogen chloride, the graft polymerization rate then becomes proportional to the square root of the dose rate, as is usual in radiation graft polymerization from the gas phase.