| abstract |
An improvement in the composition of particulate, water-insoluble alkali metal carboxylate salts of starch-acrylonitrile graft copolymers of the type which are produced by saponifying starch-acrylonitrile graft copolymers with an alkali metal base in an aqueous alcoholic medium and which particulate copolymer in its unimproved form is capable of absorbing in excess of 50 parts of aqueous fluids per part of copolymer when saturated. The improvement comprises the intermixture with the particulate copolymer of fumed silica or fumed alumina particles in an amount sufficient to increase markedly the rate at which the mixture absorbs physiological fluid as compared to the rate of absorption for such fluids exhibited by the copolymer before the fumed material is added. The mixture also minimizes the undesirable dusting tendency which is a characteristic of the particulate copolymer in the absence of the fumed silica or alumina. |