Method for polymerizing pyrrolidone with preheating of catalyst solution

摘要

An improved, consistent quality anionic catalyst for polymerizing pyrrolidone, optionally mixed with up to 25% of another copolymerizable lactam, is disclosed in which an alkali metal pyrrolidonate, prepared by reacting an alkali metal hydroxide or alkoxide with a molar excess of pyrrolidone, is heated for at least 5 hours at 100 DEG -175 DEG C. in the absence of water and air. Reproduceable results are obtained when the catalyst so heated is used to polymerize pyrrolidone.