Drying acrylamide polymers - by heating in presence of a soluble hydroxylamine or its salt as stabiliser

摘要

Drying of acrylmaide (co)polymers contg. water, or their aq. solns. by evaporation of the water in presence of 0.1-1 wt. % based on (co)polymer, of a water-soluble hydroxylamine. The water may be removed by any process e.g. or heated rolls, in a hot air fluidised bed or pref. by azeotropic distn. Drying of acrylamide polymers, or copolymers with (meth)acrylic acid and/or dialkylamino alkyl acrylates, contg. 40-100% acrylamide with mol. wt. 1-25 x 106. The (co)polymers mayb e made by soln., suspension or emulsion polymerisation, and may be highly concentrated or in dilute aq. soln. Degradation of the (co)polymers by heat, producing insoluble gels, is prevented by the hydroxylamine stabiliser.