The characteristics of polyamide layered-silicate nanocomposites

Layered-silicate, especially montmorillonites (MMTs) reinforced polymer nanocomposites, have attracted considerable interest during the recent years due to the dramatic enhancements in physical, thermal and mechanical properties of polymer materials at low filler loading. Depending on the interaction between MMTs and polymers, different microstructured nanocomposites ranging from immiscible to intercalated to exfoliated can be synthesized. In this paper, organoclay reinforced polyamide 6 (PA 6) nanocomposites have been prepared by a simple and versatile method—melt intercalation using extrusion. Their structural, thermal and mechanical properties have been systematically investigated with advanced facilities. It was found from transmission electron microscopy and X-ray diffraction evaluations that the organoclays were intercalated and dispersed evenly in the matrix. Moreover, the existence of the organoclay also affected the crystalline and thermal behavior of the polymer, the crystalline temperature, melting temperature and decomposition temperature of the nanocomposites decreased slightly with the organoclay fraction. Comparing to the thermal properties, the mechanical properties were significantly improved by the incorporation of the organoclay. The elastic modulus and tensile strength of the PA 6 nanocomposites with 7.5 wt% of organoclay increased by 57.44% and 18.37%, respectively, compared to the pure PA 6.