Thermal and Mechanical Properties of Polypropylene/Post-consumer Poly (ethylene terephthalate) Blends: Bottle-to-Bottle recycling

Abstract

In this study, the effect of the amount of maleic anhydride grafted polypropylene (PP-g-MA) (0-10 by weight %) compatibilizer on the thermal and mechanical properties of polypropylene/post-consumer poly (ethylene terephthalate) (PP/rPET) (70/30 by weight %) blends are investigated by means of melt blending method. Post-consumer PET bottle waste was recycled by means of bottle-to-bottle recycling method. The interactions between the polymers of the blends and PP-g-MA were investigated by means of Fourier transform infrared spectrometer (FTIR). The scanning electron microscope (SEM) results showed that the interfacial interactions of the polymers of studied blends improved with the increasing amount of PP-g-MA. The effect of the amount of PP-g-MA on the mechanical properties of the blends were investigated by means of tensile and flexural tests. It was obtained from mechanical tests that the tensile strength, tensile modulus, flexural strength and flexural modulus increased while elongation at break decreased with the increasing amount of PP-g-MA. The best mechanical performances were obtained by compatibilized PP/rPET blends with a tensile modulus value of 1795 MPa and flexural modulus value of 2515 MPa. The effect of the amount of PP-g-MA on the thermal properties of the blends were investigated by means of differential scanning calorimeter (DSC) and heat deflection temperature (HDT) tests. It was observed that the crystallization temperature (T-c) and HDT of the blends increased with the increasing amount of PP-g-MA.