Mechanical properties of fly ash filled high density polyethylene

Effect of fly ash as filler in mechanical properties of HDPE is described in this study. Three different particle size of fly ash was used. Concentration of fly ash was varied up to 40 % by weight. The composites were prepared using twin screw extruder and then test specimens were prepared by injection molding. Tensile, flexural and impact properties were tested. The microstructure was investigated through scanning electron microscopy (SEM) of the fractured samples. Both tensile and flexural strengths and moduli were found to increase with fly ash addition. Tensile elongation drastically reduced at fly ash concentration greater than 10%. With increasing fly ash concentration impact resistance decreased up to about 15 % fly ash concentration and then did not reduce significantly on further addition. Composites with smallest size fly ash particles proved to be better in enhancing strength and relative elongation. Modulus and impact resistance did not seem to depend much on particle size. Key words: composites; fly ash; mechanical properties; polyethylene