| abstract |
What is described herein is a precipitation polymerization process in a reaction mixture of a vinyl lactam, e.g. vinyl pyrrolidone or vinyl caprolactam, and a polymerizable carboxylic acid, e.g. acrylic acid or methacylic acid, in the presence of a polymerization initiator, in a cosolvent mixture of an aliphatic hydrocarbon solvent, particularly, a C3-C10 saturated hydrocarbon, which is branched or unbranched, cyclic or acylic, and preferably, is heptane or cyclohexane and a secondary alochol, preferably isopropanol. The copolymers obtained thereby have an advantageous low molecular weight of less than 20,000. |