Novel melt-processable nylon-6/inorganic fullerene-like WS2 nanocomposites for critical applications

Environmentally-friendly inorganic fullerene-like tungsten disulfide nanoparticles (IF-WS2) were used to produce new nylon-6 nanocomposites. The addition of IF-WS2 is an effective way to improve the thermal, mechanical and tribological properties of polymeric materials. In the present work, the nylon-6/IF-WS2 nanocomposites were processed by advantageously traditional melt processing technique. The IF-WS2 nanoparticles do not require exfoliation or modification, making it possible to obtain stronger and lighter materials without the complexity and processing cost associated with these treatments. The thermo-oxidative stability of nylon-6/IF-WS2 nanocomposites was studied using thermogravimetric analysis. The thermal behaviour and crystalline phase transition of nylon-6 were investigated using DSC and time-resolved synchrotron X-ray diffraction in order to obtain a picture describing the physico-chemical transformation of nylon-6 molecules from the non-ordered state to the ordered state. Dynamic mechanical analysis and tribological tests had been carried out to evaluate the effect of IF-WS2 on the mechanical performance, friction and wear behaviour of nylon-6/IF-WS2 nanocomposites. The results showed that significant improvement can be achieved in the thermal, mechanical and tribological properties of nylon-6 nanocomposites. In addition, the incorporation of IF-WS2 nanoparticles has shown to be an effective way to promote the crystallization process of nylon-6, which also influences the crystalline transformation of nylon-6 (i.e. Brill transition) observed during both cooling and heating processes.