Mechanical properties of nanoclay reinforced polypropylene composites at cryogenic temperature

Abstract

Polymer–clay nanocomposites are a new class of materials which improve the properties at low levels of addition of nanoclay as compared with conventional filler composites. In this article, a comparative study on the mechanical behavior of nanoclay filled polypropylene composites at both room and cryogenic temperatures is presented. Nanoclays of 1–5% by weight are added to polypropylene matrix using maleic anhydride grafted polypropylene as compatibilizer. Polypropylene/clay nanocomposites are prepared by melt intercalation in a twin-screw extruder followed by injection molding. Composite properties such as tensile and impact at both room (25°C) and cryogenic (−196°C) temperatures are calculated. The addition of clay to polypropylene matrix showed a remarkable enhancement in the mechanical properties at temperatures of 25°C and −196°C. Nearly 36.4% and 17.6% increase in the Young’s modulus and about 45% and 62.5% increase in the impact strength are observed at both room and cryogenic temperatures, respectively. Scanning electron microscopy is used to assess the surface morphology of the fractured surfaces and dispersion of the nanoclay. The morphology of polypropylene/clay nanocomposites is also characterized by X-ray diffraction analysis and transmission electron microscopy.