Short glass fiber filled waste plastic (PE) composites: Studies on thermal and mechanical properties

Plastics used in the form of carry bags, pouches, sheets and various other shapes discarded into the Municipal Solid Waste (MSW) is a major concern of environmental pollution these days. In India synthetic textiles from the garment industry and from the rubber industry also goes to the MSW stream. The objective of this paper is to combine the stiffness and strength of the short synthetic fibers with the waste polyethylene matrix to form useful products. In this study glass fibers have been chosen from the tyre industry and chopped to short fibers before mixing with waste plastics. The composites of Short glass fiber (GF) reinforced Waste Polyethylene (WPE) and neat High Density Polyethylene (HDPE) were prepared separately by melt-mixing technique in a Brabender plasticorder under optimum process conditions. Physico- mechanicalproperties of the composites at different fiber loadings were determined using standard methods. Thermal stability of the composites was determined using a thermo gravimetric analyzer. It was observed that the strength properties improved with the fiber loading up to 50 wt% of the short glass fibers; beyond which it reduced due to dilution effect. The effect of Maleic anhydride (MAH) grafting onto the waste polyethylene improved the fiber-matrix adhesion significantly. The effect of Ethylene methacrylic acid (EMA) copolymer as a matrix modifier improves the adhesion with the glass fibers. The Waste Polyethylene composites were compared with those of neat HDPE glass fiber reinforced composites, for its strength and thermal stability. Thermal stability of the composites improved as expected. The results were supplemented by fracture studies by SEM.