No abstract

Abstract

This research explores the potential of using recycled polypropylene (PP) incorporated with shrimp shell waste to produce a sustainable polymer composite. In this study, the mechanical and physical properties of recycled polypropylene/shrimp shell (rPP/ SS) composites prepared by melt compounding and compression molding techniques were evaluated. The effects of SS loading were investigated by using various compositions of rPP/SS composites, ranging from 0 to 8 wt.% SS that consists of two different sizes, i.e., fine and coarse SS. The composites were tested for their mechanical and physical properties using impact, tensile and water absorption tests. Furthermore, the morphology of the composites was examined by using a scanning electron microscope (SEM). Incorporation of SS was found to increase the Young's modulus of the rPP, but the impact and tensile strength showed a decrease. However, we observed that both the impact and tensile strength improve with the further increase of the SS content. In other words, composites with high shrimp shell loading were observed to exhibit better tensile and impact properties compared to composites with low shrimp shell loading. Moreover, at 8 wt.% of SS, the value of tensile strength is comparable to that of neat rPP.

The polypropylene (PP) reinforced with recycled carbon fibres (rCF) was successfully produced using a Haake internal mixer via melt compounding. The compounding was performed at 180°C, rotor speed of 50 rpm and compounding period of 10 minutes. The standard samples for the pin on disc testing were prepared using injection moulding. The effect of rCF filler loadings of 0.5, 1, 3, 5, 7, 10, 13, 15 and 20 wt% was studied for the tribological properties. The results were compared with 100% PP. The morphological behaviours for the effect of low and high fibre loadings were observed using scanning electron microscopy analyses. The composites with low carbon fibre loading of up to 3 wt% imposed higher resistance to dry sliding friction. In contrast, the increment of fibre loading at 5 wt% to 20 wt% decreased the wear rate of the composites due to patch film and transfer film formation. The wear mechanism of the composites for different fibre loading was graphically sketched from morphological observation. As the conclusions, the composites showed promising self-lubricating properties, capable of wear reduction with significant physical and mechanical properties.

No abstract