Imidazole polymers and preparation thereof with radiation and chemical initiator

A process of preparing water-soluble, high molecular weight imidazole polymers which comprises

• irradiating an aqueous solution comprising from 15% to about 90% by weight of monomer comprising from 5% to 100% by weight of at least one water-soluble imidazole monomer selected from the group consisting of 1-vinylimidazole, acid salt of 1-vinylimidazole, and quaternary salt of 1-vinylimidazole and from 95% to 0% by weight of at least one water-soluble monomer conforming to the formula ##STR7## wherein R is hydrogen, methyl, or ethyl and Y is --NH.sub.2, --OM, ##STR8## wherein M is a cation, R.sub.1, R.sub.2 and R.sub.3 are 1 to 4 carbon alkyl groups, and X is an anion, and
• from about 100 to about 12,000 ppm of a chemical, free-radical initiator for the polymerization of ethylenically unsaturated compounds,
• said initiator having a dissociation rate constant above about 1 .times. 10.sup.-4 reciprocal seconds at 100.degree. C., does not substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 50.degree. C., and does substantially catalyze the polymerization of ethylenically unsaturated monomers at temperatures below about 100.degree. C.,
• with high energy ionizing radiation at an intensity of from about 10,000 rads to about 1,000,000 rads per hour to a dose of from about 5,000 to about 500,000 rads,
• to form a reaction mass in which from about 30% to about 95% by weight of the 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.