Polymerization of water soluble monomers with radiation and chemical initiator

Claim 1

A process of preparing water-soluble, substantially linear, high molecular weight polymers which comprises irradiating an aqueous solution comprising from about 10% to about 60% by weight of (1) at least one water-soluble, ethylenically unsaturated monomer conforming to the formula ##EQU3## wherein R is hydrogen, methyl, or ethyl and Y is --NH 2 , --OM, ##EQU4## wherein M is a cation, R 1 , R 2 , and R 3 are 1 to 4 carbon alkyl groups, and X is an anion, and from about 5 to about 5,000 ppm of a chemical, free-radical initiator for the polymerization of ethylenically unsaturated compounds, said initiator having a dissociation rate constant above about 1 × 10.sup. -4 reciprocal seconds at 100°C., does not substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 50°C., and does substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 100°C., with high energy ionizing radiation at an intensity of from about 1,000 rads to about 1,000,000 rads per hour to a dose of from about 1,000 to about 150,000 rads, to form a reaction mass in which from about 30% to about 95% by weight of the water-soluble ethylenically unsaturated monomer initially present in aqueous solution has been converted to water-soluble polymer and in which chemically induced polymerization occurs, terminating the high energy ionizing radiation of the reaction mass before formation of water-insoluble polymer in the reaction mass, and allowing the chemically induced polymerization of the reaction mass to continue.