Polymerization of lactams, 53. Anionic polymerization of 2-pyrrolidone accelerated with CO2, part 2

The anionic polymerization of 2-pyrrolidone ( 3 ) initiated with its potassium salt ( 1 ) (2-oxo-1-pyrrolidinylpotassium) and carbon dioxide was studied under optimal conditions. On the basis of a detailed experimental analysis, it is suggested to consider the investigated polymerization in the presence of gaseous CO₂ as an accelerated non-activated polymerization. Alkali 2-oxo-1-pyrrolidine carboxylate, which is formed in the system by reaction of CO₂ with 1 , probably does not take part directly in the polymerization process and excerts only a controlling role.