Abstract: This invention relates to stable, aqueous polymeric dispersions comprised of graft copolymers of at least one vinyl monomer and a derivatized and thinned amylopectin starch, that is, a starch wherein the starch is made up entirely or almost entirely of amylopectin units such as waxy maize starch. The amylopectin starch is derivatized to a degree of substitution of at least about 0.01 and thinned to an intrinsic viscosity of not less than about 0.12 deciliters per gram. The graft copolymers have a starch/monomer ratio of less than about 100/25 by weight. The dispersions have high solids contents (25% by weight or greater) and are stable (show no excessive increase in viscosity and remain homogeneous) over extended periods of time. This invention also relates to processes for the production of the dispersions.

Abstract: This invention discloses stable, aqueous polymeric dispersions comprised of at least 25% solids, dry basis, of a starch graft copolymer of a thinned and derivatized starch and at least one vinyl monomer. The starch has a degree of substitution of at least about 0.05 and an intrinsic viscosity of not less than about 0.12 deciliters per gram. The starch graft copolymers have a starch/monomer ratio of less than about 100/25. The dispersions are stable over extended periods of time at normal storage temperatures. Processes for the production of the dispersions are also disclosed.

Abstract: This invention relates to removal of cerium, used as a free-radical initiator, from aqueous polymeric dispersions, particularly starch graft copolymer dispersions, by adsorbing cerium (III) onto a strong cation exchange resin, to separation of the adsorbed cerium (III) from the resin using a solution such as sodium sulfate or sodium oxalate to form a cerium (III) precipitate, and to oxidation of the separated cerium (III) to cerium (IV).

Abstract: Acid modified oxidized hydroxyalkyl starch is prepared by the sequential steps of:(a) reacting granular starch with a 1,2-alkylene epoxide under conditions whereby starch having a hydroxyalkyl D of S of from about 0.02 to less than about 0.18 is obtained and the granular nature of the starch is maintained,(b) oxidizing the hydroxyalkyl starch with an alkaline hypochlorite under suitable conditions to introduce an amount of carboxylic groups onto said starch, the amount being no greater than about 1.2 minus the product of 7 times the hydroxyalkyl D of S,(c) treating the oxidized hydroxyalkyl starch with an acid to increase the alkaline paste fluidity thereof, and(d) recovering the resulting product.

Abstract: Granular starch is partially depolymerized by reaction with hydrogen peroxide in the presence of a salt selected from the group consisting of alkali metal chlorides, ammonium chlorides and mixtures thereof, and cupric ions while maintaining the pH of the reaction mixture in the range of from about 5.5 to about 7 by the addition of alkali thereto.