The Morphological, Thermal And Mechanical Properties Of Ground Rubber Tire (Grt) Filled Waste High-Density Polyethylene (Rhdpe)

Abstract

This research investigates the morphological, thermal and mechanical properties of ground rubber tire (GRT) filled waste high-density polyethylene (rHDPE), showing the effect of variable particle sizes. In the adopted methodology, the samples were prepared through melt mixing (using two-roll mill machine), tailed by compression molding, different blends of variable particle sizes were prepared (150 µm, 212 µm, 300 µm and 425 µm) and a control sample of 150g rHDPE was also prepared. The morphology, thermal properties and mechanical properties of the developed composites are analyzed using Scanning electron microscopy (SEM), Dynamic Mechanical Analysis (DMA), tensile and flexural tests respectively. The SEM result shows some inhomogeneity and poor dispersion of the GTR filler which attributed to improper stress transfer along the interface and formation of cracks in the developed polymer composited, causing reduction in mechanical strength. A more homogenous morphology with reduced defects was observed upon increasing the filler content from 150µm to 212µm, leading to an improved interfacial adhesion with the HDPE matrix. Further increase (from 212µm to 300µm) gave more homogenous micrograph but addition of GTR particles up 425µm led to rough surface. For thermal behavior, as the different sizes of the GRT filler were introduced into the HDPE matrix, the storage modulus decreases, attributed to the material softening caused by the soft rubber particles which result in lower rigidity except for sample made with 150 µm. Incorporation of 300 µm particles of GTR results in higher rigidity, which similarly gave more homogenous micrograph with uniform dispersion. The result also shows that, increasing the GTR particles causes decline in the flexural stress and modulus, having similar trend with the tensile modulus. The elongation at break also shows a decline with addition of the different particle sizes of the filler, with the exception of sample 300µm.