Polymerization of lactams

Summary The following limit (ceiling) temperatures of polymerization were extrapolated from kinetic data for the anionic polymerization of 2-pyrrolidone initiated with potassium salt of 2-pyrrolidone and the initiation systems of optimum compositions: 66°C for the nonactivated polymerization, 68°C and 73°C for the polymerization accelerated with 1-(1-pyr-rolin-2-yl)-2-pyrrolidone and carbon dioxide, respectively, 73°C and 76°C for the polymerization activated with N-benzoyl-2-pyrrolidone and N-acetyl-2-pyrrolidone,respectively.