Effect of chain extenders on the structure and properties of poly(ethylene terephthalate)/polypropylene blends reinforced with fiber and filler

In recent years, the depletion of raw material resources and the increase in prices have caused environmental and economic concerns to increase rapidly. This situation has increased the importance of reducing the amount of waste and using recyclable products. It draws attention to the design and production of industrial products with high added value, especially from post-consumption PET bottle waste, whose waste volume is very high worldwide. Polypropylene (PP)/post-consumer recycled poly(ethylene terephthalate) (rPET) blend has gained much attention as an environmentally friendly and economical material in various industrial applications. In this study, it was aimed to improve the properties of talc, glass fiber and carbon fiber mixture and PP/rPET blend. In this context, PP/rPET blends and the preparation of multifunctional PP/rPET composites were examined in two separate sections. First, PP/rPET mixtures were prepared by melt blending method and then injection molded. The prepared blends were examined by tensile test, bending test, differential scanning calorimetry (DSC), heat deflection temperature (HDT), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The PP/rPET composition providing the best mechanical and thermal properties was determinated. In the second step, PP/rPET composites were injection molded after being prepared by melt blending method. Maleic anhydride grafted polypropylene (PP-g-MA) and Joncryl® ADR were used as coupling agents. Mechanical, morphological, electrical and thermal properties of PP/rPET hybrid composites were evaluated in terms of the effects of bonding agents. The mechanical properties of the composites were characterized by tensile and notched Charpy impact tests. The morphology of the composites and the distribution of the filler were characterized by SEM. The thermal properties of the composites were characterized by DSC, HDT and Vicat softening temperature (VST) tests. In the determination of electrical conductivity, solid conductivity test was performed. As a result, multifunctional PP/rPET composites with high thermal and mechanical properties were obtained in the presence of chain extender. Keywords: rPET, PP/rPET, chain extender, recycling, composit