Abstract: A process for preparing a modified polysaccharide graft copolymer complex which comprises the steps of:i. subjecting polysaccharide to graft copolymerization with a vinyl monomer;ii. treating the polysaccharide graft copolymer with:a. polyethylene glycol to provide a polymer-PEG complex; orb. a silicate compound to provide a silica precipitated polymer; andiii. recovering the polymer-PEG complex or silica precipitated polymer.This modified polysaccharide graft copolymer may be used as a surface sizing agent in the preparation of paper.

Abstract: A process for the manufacture of paper from pulp employs at least one graft copolymer of starch selected from the group consisting of starch graft-polymethacrylic acid, starch graft-polyacrylic acid, cationic starch graft-polymethacrylic acid and cationic starch graft-polyacrylic acid as a wet-end additive. The graft copolymer preferably has an add on amount of acid of from about 0.1 to about 50% based on the weight of the starch, and is typically added to cellulosic pulp in an amount of from about 0.1 to about 10% based on the weight of the pulp. Such wet-end additives are also useful in processes involving relatively high alum levels of up to about 15 or 25%, based on the weight of the pulp.