Clay mineral/polyamide nanocomposites obtained by in-situ polymerization or melt intercalation

Series of so far undescribed clay mineral polyamide nanocomposites (CPN) were prepared by hydrolytic polymerizations of η-capryllactam (L8), ω-laurolactam (L12) and N-methyl-ω-laurolactam (ML12) initiated with 12-aminododecanoic acid (ADA) in the presence of a organomontmorillonite (OMt). Polymerization process was markedly accelerated due to a contribution of acidolytic and cationic polymerization on the intercalated ADA and its hydrochloride. Simple kinetics of polymerization with constant number of growth centers is valid up to a high polymer yield for all the lactams under study. For the sake of comparison, polyamide 6 nanocomposites were synthesized both by the method of the in-situ ε-caprolactam (L6) polymerization and by polyamide 6 melt blending. Structures of the CPN were analyzed by X-ray diffraction.