Polymerization of lactams, 92 Non-activated anionic polymerization of epsilon-caprolactam initiated with the sodium salt of epsilon-caprolactam

The non-activated polymerization of E-caprolactam initiated with the sodium salt of E-caprolactam (CLNa), which was prepared in situ with sodium metho xide, was studied in the temperature range 170-230 degrees C and at CLNa co ncentrations from 0.20 to 1.0 mol-%, and at 190 degrees C in the presence o f 2.0-10.0 mol-% CLNa. Apparent rate constants and values of apparent activ ation energy (E-a) were determined for the initial autoaccelerated stage of polymerization (E-a= 230 kJ mol(-1)) as well as for the stage characterize d by a zero-order reaction with respect to the monomer (E-a= 120 kJ mol(-1) ). Non-integral orders of the polyreaction with respect to the initiator in dicate a highly complex polymerization mechanism. Degradation reactions acc ompany the polymerization at high polymer contents.