Compatibilization of immiscible polymer blends (R-PET/PP) by adding PP-g-MA as compatibilizer: analysis of phase morphology and mechanical properties

In the current study, the compatibilization of polypropylene/recycled polyethylene terephthalate (PP/r-PET) blends with different percentages of maleic anhydride (PP-g-MA) was examined. Exploited resource for r-PET was used as water bottles. Specimens of PP/r-PET blends in different percentages, i.e., 90/10, 70/30, and 50/50 were prepared in a corotating twin-screw extruder to evaluate the mechanical properties. Results indicated that PP-g-MA improved compatibilization of the PP/r-PET blends (modulus of elasticity and yield stress were enhanced to about 1450 MPa and 30 MPa) and also enhanced the morphological and mechanical properties. By adding about 2% of the compatibilizer into specimens containing 10% of r-PET, the highest enhancement in mechanical properties was achieved. Besides, both yield strength and the impact of energy were improved 8.3% and 24.6% by increasing the amount of 50% and 10% r-PET in the system. Also, results showed that specimens have higher yield stress and modulus of elasticity after 10 days compared to those specimens without aging due to the presence of stronger interaction after a period of time.