Studies on polymerization and depolymerization of ϵ‐caprolactam polymer. III.. On the reactions at the initial stage of the ϵ‐caprolactam polymerization

Abstract

Abstract The rate of reaction of the compound having COOH, NH 2 , COO − ,NH or H + with ϵ‐caprolactam was studied and the catalytic function in the ϵ‐caprolactam polymerization was ascertained to be due to, only amino or ammonium cation residues, or hydrogen cation. The catalytic effect of amino acid is greater as amino‐ and carboxyl‐residues are subjected to less ionic interaction, i. e., they are apart from each other in a molecule. As such a intramolecular ionic interaction is considered to be related to the electric conductivity, that of the said compound in water, in aqueous solution of 80% ϵ‐caprolactam, or in pure molten ϵ‐caprolactam was measured. Furthermore, initial reaction products were analyzed by paperchromatography. From these experiments, it has been concluded that the reaction of ϵ‐caprolactam with the chain molecule becomes more rapid as the chain molecule grows, therefore the reactivity of the functional end‐group depends on the chain length, especially in the range of chain oligomers.