Patent ID: 6040379
Filing Date: 2000-03-21
Classification: C08B,C08F

Abstract:
A method for the preparation of a starch copolymer product which is the reaction product of starch and one or more synthetic monomers capable of undergoing free radical polymerization wherein said reaction product is in the form of an emulsion or dispersion having weight-average particle sizes less than 180 nm as measured by Capillary Hydrodynamic Fractionation comprising the steps of:(a) dissolving or colloidally dispersing starch in an aqueous solvent to form a starch solution or dispersion;(b) heating the starch solution or dispersion to a specified temperature range;(c) adding to the starch solution or dispersion a first portion of said synthetic monomer and a free radical initiator for initiation of polymerization of the starch component and said synthetic monomer; and(d) after free radical polymerization of said synthetic monomers has been initiated in the presence of said starch, adding additional portions of synthetic monomer capable of undergoing free radical polymerization to the starch solution or dispersion wherein at least 75% of the total synthetic monomer to be reacted with said starch is added more than one hour after initiation of said free radical polymerization.