Mechanical and Morphological Properties of Fluted Pumpkin Stem Fiber (Telfaira occidentalis) Recycled High Density Polyethylene Nanocomposites

Abstract

The outstanding characteristic properties of nanographene such as high aspect ratios and improved mechanical properties in comparison with other types of nanofillers like carbon nanotubes and clays has accelerated their use as nanosize filler in polymer matrix composites. The litter of agro-wastes is a critical issue which must be addressed for the preservation of the global environment. The effect of nanographene addition on the mechanical and morphological properties of nanocomposites prepared using fluted pumpkin stem fiber (FPF) and recycled high density polyethylene (R-HDPE) was investigated. Four weight levels of nanographene 0, 0.5, 1.5 and 2.5 wt % were mixed with 65 wt. % HDPE, 35wt. % FPF and 3wt% maleic acid anhydride produced using melt compounding and the extruded nanocomposites was shaped by injection molding machine for the mechanical tests. The results showed that addition of 0.5 wt % nanographene increased the flexural strength, flexural modulus and notched impact strength by 24.77MPa, 1800MPa and 32.61J/m2, compared to the control samples 20.5MPa, 1500MPa and 19.35J/m2 respectively. Although the addition of nanographene to the FPF/HDPE composite significantly improved the flexural strength, flexural modulus and notched impact strength, these improvements came at a unique nanographene loading of 0.5 wt %. The morphological images revealed that the samples with nanographene loading of 0.5 wt. % showed no fiber pullout/holes, whereas higher contents (1.5-2.5wt %) of nanographene exhibited fiber pullout/holes and were easily agglomerated. This study has shown that fluted pumpkin stem fiber could be used in composite formulation with good results comparable to wood-plastic-composites.