Журнал материаловедения и инженерии

Effect of High Impact Loading on Nanoclay Reinforced Polypropylene

Abstract

Gebremeskel SA and Bhatnagar N

Except for few attempts to show the high impact load effect, the difference in level of contribution of nanoclay on polymers at their quasi-static and dynamic mechanical behaviors is a lacuna in the available literature. Quasistatic and dynamic responses of a high impact copolymer polypropylene (PP) in its neat and nanoclay-filled forms are presented in this study. The study helped in percentage quantification of differences in nanoclay effect, imposed by the very nature of loadings. The PP-nanoclay nanocomposite (PP+5 wt%nc) is prepared by melt compounding of 5 wt% nanoclay (nc) with PP using twin screw extruder. Tensile specimens for UTM (Universal Testing Machine) were prepared using injection molding machine. Dynamic loading specimens were made for SHPB (Split Hopkinson Pressure Bar) using an extruded sheet. The experiments were performed at strain rates of 10-2 s-1 and 2.2*104 s-1 for quasi-static and dynamic loadings respectively. As a result, the contribution of 5 wt% nanoclay on PP at quasi-static loading is shown to be 2.6%, 10.8% and 13% on Yield stress, Young’s modulus and toughness, respectively. However, significantly different results are observed after dynamic loading experiments. Intense improving contributions of 506% and 53% in impact modulus and impact toughness respectively are observed. While, minor reduction (3.5%) in plateau (Yield) stress is experienced in the case of dynamic impact loading.