Polymerization of lactams, 93. Formation of 6-hexanelactam cyclic oligomers

The formation and decay of cyclic oligomers during hydrolytic polymerization, cationic polymerization, and autocatalytic polymerization of 6-hyxanelactam carried out at 260°C was followed by means of the high performance liquid chromatography (HPLC) analysis of portions extracted with methanol from the polymerization products. It was proved that the type of initiation system substantially affects the formation mechanism of cyclic oligomers. In the autopolymerization of 6-hexanelactam, the concentration of cyclic oligomers as a function of monomer conversion confirms a change of the predominant reaction mechanism during the polymerization.