Reinforcement of Polyethylene Terephthalate (PET) Waste Polymer Using CaO Nanoparticles Synthesized from Periwinkle Shell for Car Bumper Application

Abstract

This study investigated the reinforcement of waste polyethylene terephthalate (PET) with calcium oxide (CaO) nanoparticles synthesised from periwinkle shells for potential car-bumper applications. The shells were washed, dried, milled, calcined at 1000 °C, and sieved, while the CaO nanoparticles were prepared using maceration method. The synthesised nanoparticles were characterised to determine their structural and compositional properties. Fourier-transform infrared spectroscopy confirmed the presence of Ca–O, carbonate, and hydroxyl groups. Particle-size analysis indicated a Z-average diameter of 37.12 nm. X-ray fluorescence analysis showed that the particles consisted mainly of 83.637 wt.% CaO and 7.166 wt.% MgO. The nanoparticles were incorporated into molten waste PET at different proportions to produce samples S1–S5, with sisal fibres added as reinforcement. The mechanical properties of the resulting composites were evaluated and compared with those of a commercial car-bumper sample designated Control 2. Samples S1 and S3 showed the most promising performance. Sample S1 recorded a hardness of 60.67 Shore D and an impact strength of 0.0028 J/mm, whereas Control 2 recorded 63.67 Shore D and 0.0003 J/mm, respectively. Sample S1 also exhibited a higher tensile strength than Control 2, although its flexural strength was lower. The findings indicate that the composites may have potential for car-bumper and other automotive applications if their flexural performance is improved.