Structural and Mechanical Properties of Needle-Punched Nonwoven Reinforced Composites in Erosive Environment

Polypropylene-based needle-punched nonwoven reinforced epoxy composites have been fabricated and were evaluated for their thermomechanical response and dry erosion performance. The erosive wear investigations were carried out using silica sand particles as erodent with varying impact velocity, angles of impingement, fiber content, and stand-off-distance as the operating variables. Design of experiments (DoE) approach-based Taguchi analysis was carried out to establish the interdependence of operating parameters and erosion rate. Impingement angle and impact velocity have been found to be the most significant determinants of erosive wear performance of such nonwoven reinforced composites. The composites were also observed to be appreciably resistant to impact content and indentations in addition to exhibiting the absence of any storage-modulus decay till 60 degrees C accompanied with a nominal increase in the primary transition temperature as revealed from loss-tangent peaks. The composite with 30 wt % and 40 wt % of nonwoven materials have shown the highest and lowest erosion rates, respectively. The morphology of eroded surfaces was examined by using scanning electron microscopy (SEM) and their possible erosion mechanisms are discussed. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 1698-1707, 2012