Caprolactam-Laurolactam Copolymers: Fast Activated Anionic Synthesis, Thermal Properties and Structural Investigations

Anionic poly(caprolactam-co-laurolactam) has been isothermally synthesized at 155°C by hexamethylene dicarbamoylcaprolactam as fast activation agent and two Na lactamates (from the mixed monomers or neat caprolactam, respectively) as initiators. The specific roles of both the chosen initiator and the laurolactam content in the feed have been investigated in terms of high polymer yield, structural defects of the polymer chains due to side reactions, Tg and Tm values, degree of crystallinity, molecular and superlattice order of the copolyamides. Namely, structural and thermal peculiarities of the latter have been brought into evidence on as-polymerized samples as well as on high polymers after the deoligomerization process. Interesting differences among the various materials have been found and some possible explanations of the above behavior are given.