Effect of tungsten disulfide nanotubes on the thermomechanical properties of polypropylene-graft-maleic anhydride nanocomposites

Abstract

In this work, the influence of tungsten disulfide nanotubes (INT-WS2) on the mechanical, thermal, structural, and morphological characteristics of Polypropylene-graft-maleic anhydride (PPGMA) nanocomposites is investigated. The addition of 5% INT-WS2 increases the Young's Modulus by 28.5% and the storage modulus by 196.5% (in the rubbery state). Furthermore, the nanocomposites' thermal stability increases (up to 10 °C) with the addition of INT-WS2. Transmission electron microscopy observations of the nanocomposites revealed that nanotubes' length is significantly reduced during processing and that nanotubes are well-dispersed inside the PPGMA matrix. DSC results indicated that INT-WS2 serve as nucleating agents in PPGMA. Moreover, AFM observations (coupled with DSC results) suggested the formation of fibrillar crystallites in the nanocomposites. This interfacial crystalline structure seems to interpose between the PPGMA and INT-WS2. Thus, it plays a crucial role in the load transfer from the amorphous part of the polymer to the rather stiff INT-WS2.