Novel polypropylene/inorganic fullerene-like WS2 nanocomposites containing a β-nucleating agent: Mechanical, tribological and rheological properties

Environmentally friendly inorganic fullerene-like tungsten disulphide (IF-WS2) and N,N'-dicyclohexyl-2,6-naphthalene (NJ) as dual-additive mixtures are introduced into an iPP matrix to generate new materials that exhibit variable alpha and beta polymorphism. A traditional melt processing strategy was employed providing a versatile, economic and scalable route to the development of novel composites with improved properties. The effects of the relative concentration of NJ on the mechanical, tribological and rheological properties are investigated and the results are compared to those of binary reference systems, iPP/NJ and iPP/IF-WS2. In particular, we have found that the mechanical and tribological properties of the hybrids can be finely tuned by adjusting the beta(NJ)/alpha(IF-WS2) ratio. The combined results of the different tests demonstrate that the incorporation into iPP of the dual additive system, IF-WS2 (nanoparticles) and NJ (microparticles), provides a good balance between stiffness, strength, toughness and wear resistance, making these multiscale nanocomposites suitable for industrial applications. (C) 2014 Elsevier B.V. All rights reserved.