Polymerization of unsaturated monomers with radiation in the presence of salts
AssigneeHercules Incorporated
InventorsCharalambos J. Phalangas, Alfred J. Restaino, Han Bo Yun
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Abstract
Improved process for the preparation of water-soluble, substantially linear, high molecular weight polymers, comprising irradiating an aqueous solution of an ethylenically unsaturated monomer and a water-soluble salt under controlled conditions of concentration, radiation intensity, conversion, and total radiation dose. The polymers may be obtained in aqueous gel form or recovered in the form of powder. The polymers are useful as flocculating, thickening, and mobility control agents.
Claims20
A process for preparing a water-soluble, substantially linear, high molecular weight polymer which comprises irradiating an aqueous solution having a pH from about 2 to about 12 and containing from about 10% to about 40% by weight of:
- (a) an ethylenically unsaturated monomer having the formula (I) ##STR3## (b) mixtures of monomers of formula (I), or (c) mixtures of at least one of the monomers of formula (I) with up to 50% by weight of an ethylenically unsaturated monomer selected from the group consisting of vinyl sulfonic acid, alkali metal salts of vinyl sulfonic acid, diacetone acrylamide, and mixtures thereof, provided that said mixture of monomers is water-soluble, wherein R represents hydrogen or methyl and Y represents --NH.sub.2, --OM, ##STR4## wherein M is hydrogen H.sub.4 N.sup.+, alkali metal, or any other cation yielding a water-soluble, polymerizable compound, R.sub.1, R.sub.2, and R.sub.3 are 1 to 4 carbon alkyl radicals and X is an anion, and containing at least about 3% by weight of a salt selected from the group consisting of potassium sulfate, potassium chloride, potassium fluoride, potassium bisulfate, tribasic potassium phosphate, dibasic potassium phosphate, monobasic potassium phosphate, sodium sulfate, sodium bisulfate, sodium chloride, tribasic sodium phosphate, dibasic sodium phosphate, monobasic sodium phosphate, lithium sulfate, lithium bisulfate, lithium chloride, ammonium sulfate, ammonium bisulfate, ammonium chloride, tribasic ammonium phosphate, dibasic ammonium phosphate, monobasic ammonium phosphate, ammonium fluoride, aluminum sulfate, aluminum chloride, and mixtures thereof, with high-energy ionizing radiation at an intensity of from 1,000 to 200,000 rads per hour to a total radiation dose of from about 1,000 to about 30,000 rads, to form an aqueous solution of a water-soluble, substantially linear, high molecular weight polymer, provided that when the aqueous solution contains at least 3% by weight of a water-soluble salt selected from the group consisting of aluminum sulfate, aluminum chloride, and mixtures thereof, the unsaturated monomer consists of from 5% to 100% of cationic monomer and from 95% to 0% nonionic monomer, and the aqueous solution has a pH from about 2 to about 5, and provided that the aqueous solution has a pH of from about 7 to about 9 when the water-soluble salt is an ammonium salt.
Dependencies are inferred from the claim text.