Investigation of the polymerization of octanelactam initiated with hydrochloric acid

Abstract

The polymerization of octanelactame (1) initiated by HCl takes place according to the characteristic kinetic curves. Both characteristics, i. e., the fast initial and the extremely slow further stages, and the kinetic anomaly (in certain cases under otherwise identical conditions less polymer is formed at higher than at lower temperatures) can be interpreted easily on the basis of a mechanism already suggested by the authors. The two relevant chain growth reactions, i. e., lactam addition on RfiH,-groups and the reaction between &H3 and N-acylamide groups, proceed through a tetrahedral intermediate in two directions, one of them being the known chain growth, the other one an amidine (or acylamidine) formation, in which the active groups, ensuring chain growth, desactivate. Both kinetic characteristics could be interpreted on the basis of the suggested mechanism, by measuring the amounts of amino and amidine groups with the progress of polymerization.