PROCESS FOR PREPARING SUBSTANTIALLY PURE HIGH MOLECULAR WEIGHT VINYL LACTAM-QUATERNIZED ACRYLAMIDE COPOLYMERS

摘要

The invention relates to the production of high molecular weight copolymers of vinyl lactam-amino quaternized acrylamide comprising less than 0.1% of residual unreacted monomer, comprising: subjecting the monomers to solution polymerization in the presence a buffering agent having chelating properties, to form complexes with heavy metal traces; to establish the pH of the polymerization at a level greater than 5.5, while by boiling continuously nitrogen gas in the system during the reaction, and adding gradually a primer free radical in two at four stages during the conversion into copolymer. The invention also relates to substantially pure copolymer of acrylamide-vinyl lactam having a Brookfield viscosity of at least 75,000 cps, and a residual monomer content of less than 0.5% by weight, for example less than 1000 ppm.