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.

Enhancements of clay exfoliation in polymer nanocomposites using a chemical blowing agent

“…Also, Othman et al revealed that the addition of just 2 wt% maleic anhydride‐grafted polypropylene (PPgMA) improved the tensile modulus of neat polypropylene (PP) and PP/clay composites. The presence of the maleated compatibilizer also enhanced the tensile strength and the elongation at break of PP/clay composites by improving the dispersion of clay in the polyolefin, strengthening the interfacial bonding and facilitating stress transfer from the apolar polymer matrix to the inorganic filler …”

The Influence of Sub-Zero Conditions on the Mechanical Properties of Polylactide-Based Composites

“…The values of elongation at break of the pure PLA and its composites are lower in comparison to the room temperature results. This result is typical for thermoplastic composites and it is commonly explained by reduced molecular mobility of the polymer at low temperatures [ 67 ]. What is more interesting, the elongation at break of the composites no longer depends on the oil content in the filler—the ε value of the PLA-LC-39.8 sample decreases from 45% at 24 °C to 4.8% at −40 °C.…”

“…The tensile strength of PLA tested at −40 °C is 110 MPa. Similarly to the increase in Young′s modulus, the enhancement of Rm at sub-zero temperatures can be explained by the intensification of the interactions between the polymeric chains, which come into close proximity with one another [ 67 ]. The composites show tensile strength −40 °C lower than the pure polymer but still higher in comparison to the results achieved at room temperature.…”

Investigation of improvement of thermal and mechanical properties of polypropylene / nano clay composites

“…10- 12 Nanoclays have a great research interest due to its unique features which are including very high aspect ratio, and its ability to be dispersed within the polymer matrix.…”