Nylon-6 and single-walled carbon nanotubes polyamide composites

Abstract

Two methods for the functionalization of single-walled nanotubes were proposed, namely grafting of acyllactam groups or amine-terminated polyimides. Such modification allows for the preparation of stable nonsagging nanotubes dispersions in the melted ∊-caprolactam. These dispersions were further utilized for in situ ring-opening anionic polymerization of ∊-caprolactam with ∊-caprolactam magnesium bromide as a catalyst and N-acetyl-∊-caprolactam as an activator. Some unique features of the obtained novel nylon-6/nanotubes composites are significantly increased thermal stability ( T 5% up to 400°C), enhanced compression modulus and Izod impact strength of polymer blocks (by 25% and 150%, respectively) and advanced tensile strength and elongation of polymer films. Such an improvement in the properties of the composites in comparison with neat nylon-6 was gained by the addition of as little as 0.1–0.01 wt% of modified nanotubes.