Solution feed, slurry polymerization process for the production of copolymers of maleic anhydride and an alkyl vinyl ether having predetermined specific viscosities

摘要

What is described herein is a solution feed, slurry precipitation polymerization process for making copolymers of maleic anhydride and an alkyl vinyl ether within a predetermined viscosity range. The process of the invention is characterized by precharging a large excess of the alkyl vinyl ether in a reactor, feeding maleic anhydride dissolved in a minimum amount of an organic solvent into the precharged reactor, and polymerizing the monomers in the presence of a free radical initiator. The copolymer product then appears as a pumpable slurry in the reaction medium. The slurry is discharged from the reactor and the desired copolymer is obtained therefrom as a fine, white powder having specific viscosities in the range of about 1.5-6.0, and preferably about 2.6-3.5.