Mineral Filler Hybridization in Recycled Polyethylene Terephthalate

This study focused on evaluating the mechanical, thermal, and morphological properties of recycled polyethylene terephthalate (RPET) hybrid mineral-filled composites containing fine acicular wollastonite, mica phlogopite, and talc platelets. Depending on the filler content, both single mineral-filled composites as well as hybrid mineral–filler composites were investigated. The maximum nominal filler content was set to 20% by weight with varying ratios for combinations of the wollastonite–mica and wollastonite–talc composites, respectively. Aside from the tensile, compression, and flexural properties, the heat distortion temperature and degree of crystallinity were carried out. Moreover, the dynamical response of the hybrid mineral-filled composites on different frequencies (1 Hz, 2 Hz, 5 Hz, and 10 Hz) was considered. By using scanning electron microscope photography, the fracture surface and the morphology of the composite material were observed. The results demonstrated enhanced stiffness, strengths, and thermal stability for all hybrid mineral-filled composites. In particular, the wollastonite–talc-filled RPET composites revealed a good compatibility and showed the most beneficial results.