Mechanical properties of hybrid recyclate glass fibre - montmorillonite nanofiller reinforced polymer nanocomposite

Abstract

Glass fibre reinforced polymer (GFRP) waste quantity is reported to increase every year and contributing to the majority of composites waste. The awareness for a greener world has led to the recycling of GFRP waste. Previous studies focus on extracting the recycled fibres from GFRP waste and reintroducing the reclaimed fibres back into various types of polymer matrix to produce new composite materials. However, there is a lack of study conducted on the potential use of recycled fibres hybridized with nanoclay. This research highlights on recycled glass fibre (rGF) as a potential reinforcement in polymer composite, as green alternative to virgin glass fibre. The aim of this study was to investigate the effect of montmorillonite (MMT) nanoclay on the mechanical properties of rGF – unsaturated polyester (UP) composites. The selected parameters were rGF fibre sizes and loading, MMT weight percentage and the hybridization effect of rGF with MMT. The grades of rGF were raw (unsieved), fine and coarse, while the fibre loading ranges were from 5% to 45% by weight. Various MMT nanoclay weight percentage ranges from 0.5% to 7% were studied. The rGF samples were prepared using mechanical grinding, prior being fabricated by hand lay-up and followed by compression moulding. The effects of varying experimental parameters were observed in composites tensile, flexural, and compression properties. Mathematical formulae for every mechanical properties including all interaction factors were developed. The results from tensile and flexural tests revealed that rGF size was the most significant factor influencing its strength. The tensile strength of 30% coarse rGF was the highest among all samples while coarse rGF at 35% fibre loading showed the best flexural strength. For hybrid rGF-MMT composites, tensile strength showed improvement at 0.5% MMT inclusion. The flexural test demonstrated that the inclusion of rGF increases the flexural modulus by approximately 300% compared to pure UP. The addition of rGF and MMT was also improved the compression properties of composites by about 200% compared to pure UP. The morphology analysis showed that a good adhesion between rGFresin bonding was observed at low MMT percentage. Transmission electron microscopy of UP-MMT nanocomposites showed that at 1 wt.% MMT, the nanoclay is well dispersed. Based on the results, hybridization with MMT nanoclay can be a green alternative solution to improve mechanical properties of rGF-UP composites and at the same time providing recycling solution to GFRP waste.