Study on Recycling of Waste Glass Fiber Reinforced Polypropylene Composites: Examination of Mechanical and Thermal Properties

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Sözen E., Cevahir A., DENİZ S.

Journal of the Turkish Chemical Society, Section A: Chemistry, vol.10, no.1, pp.63-76, 2023 (Scopus) identifier identifier


This study presents the preparation of short glass fiber reinforced polypropylene (PP/FG) composites using with waste (post-consumer) polypropylene composite containing long glass fiber (PP/LFG) obtained from the recycling of battery covers of trucks. Waste PP/LFG composite parts were mechanically grinded before adding to PP/FG composites. An injection molding machine was used to produce the PP/FG composite test samples loading with recycled waste PP/LFG composite in the range of 1-20% by weight. Effects of recycled waste PP/LFG content on the mechanical, thermal, and morphological properties of the PP/FG composites were investigated. The following three different tests, at various waste PP/LFG ratios, were conducted: Izod/Charpy Impact test, bending test, and tensile test. Mechanical test results showed that mechanical strength of prepared PP/FG composites were not influenced by content of waste PP/LFG material up to 10 wt.%. Differential scanning calorimetry (DSC) was used for the evaluation of thermal parameters such as melting point and crystallization temperature of the polymer matrix in the composites studied. Furthermore, by analyzing the values of thermal effects determined using the DSC method, it was possible to determine the degree of crystallinity. The DSC results showed that crystallinity %, melting, and crystallization temperatures of PP/FG composites were not influenced to adding waste PP/LFG at different ratios. The morphology of composite materials was investigated by SEM analysis. Good fiber dispersion was observed in the PP matrix for PP/FG composites containing short glass fiber prepared with all ratios of recycled waste PP/LFG material containing long glass fiber.