NOVEL SYNTHETIC APPROACHES TO POLY(EPSILON-CAPROLACTAM)-BASED MATERIALS

Our study has been focused on the fast anionic polymerization of epsilon-caprolactam (CL) under isothermal conditions, both in bulk and in suspension, in the temperature range between 150 and 200-degrees-C. A careful choice of the reaction parameters (type and concentration of activator, polymerization temperature and rate, cooling rate after polymerization) enabled us to find experimental conditions suitable for minimizing the extent of side reactions and, consequently, the concentration of UV-absorbing structures incorporated in the poly(epsilon-caprolactam) (PCL) chain. In terms of structural regularity, the resultant PCL compares favorably to the corresponding polyamide synthesized by the hydrolytic process. Moreover, extension of this approach to the anionic polymerization of CL in suspension allowed us to obtain particulated PCL, characterized by controlled size and surface porosity. Several PCL-based materials, formed by seeded suspension polymerization, have been obtained. Potentials of this new synthetic approach are outlined.