Abstract: A method for obtaining graft copolymers of cellulose or protein fiber with vinyl monomers, comprising the steps of impregnating cellulose or protein fiber with an aqueous solution of ferrous salt, removing excessive ions of ferrous iron, and grafting vinyl monomers to cellulose or protein fiber from an aqueous solution, aqueous emulsion or aqueous dispersion of a vinyl monomer, containing hydrogen peroxide and a reducing agent. The latter is hydrazine sulfate, sodium sulfide, glucose, sodium hypophosphite, sodium bitartrate or hydroquinone taken in an amount of 0.002 to 0.02 percent by mass. The method provides for a high rate of graft polymerization and rules out the formation of a free homopolymer in the reaction mixture. It can be carried out as a continuous and batch process.

Abstract: A method for preparing modified graft copolymers of cellulose with monovinyl monomers containing ionic groups or non-ionic groups capable of being converted to ionic ones involving a free-radical polymerization of said monovinyl monomers onto cellulose in the presence of a free-radical type initiator and modification of the resulting graft-copolymers of cellulose with said monovinyl monomers. The processes are performed in one stage in the presence of a modifying agent, that is, divinylbenzene taken in an amount ranging from 1 to 5 mol. % of the monovinyl monomer. The static exchange capacity of the modified graft copolymers of cellulose in the form of cationites is as high as 5 mg-equiv/g. The static exchange capacity of the graft copolymers of cellulose in the form of anionites is as high as 3.5 mg-equiv/g. The degree of swelling in water at a temperature of 20.degree. C. is within the range of from 180 to 200%. The modified graft copolymers of cellulose have a fibrous structure.