Influence of compatibilizer on mechanical properties of pristine and recycled PP/PE blends

CAREN ROSALES; CELINA BERNAL; VALERIA PETTARIN; REGIANE DEFACIO DUTRA; MARIA ALEJANDRA COSTANTINO; GUIDO PALAZZO

Roma

Conferencia; 2nd International Conference & Expo on Recycling and Waste Management; 2019

One of the big engineering challenges in recycling thermoplastics is to manufacture competitive products in terms of mechanical properties such as toughness or strength, i.e. to upcycling. Upcycling is a process by which recycled waste is transformed into materials with improved performance, adding value and widening their application field. One of the strategies to improve PE/PP blends performance is to add a special compatibilizer, and this is the aim of the present work. In order to achieve this objective, five different pristine blends were prepared: without compatibilizer and with four different commercial masterbatch compatibilizers based on copolymers. The compatibilizer that induced the best performance in PE/PP blends was selected to be applied in post-consumer recycled (PCR) blends, after minimizing its dosage to diminish costs. The performance of recycled blends was also studied with and without masterbatch compatibilizer. Blends were prepared in a single screw extruder simulating industrial processing conditions and then processed via compression molding into plaques. Microstructure and morphology of blends were analyzed by DSC and SEM. Tensile and fracture tests were carried out on mode I double edge-notched tensile specimens (DENT) at quasi-static loading conditions (2 mm/min). Fracture surfaces were studied by SEM. It was observed that results found for pristine blends were consistent with those of recycled blends, and the addition of compatibilizing masterbatchs improved the performance of both pristine and recycled PP/PE blends, in spite of the unpredictable composition and the presence of impurities of PCR blends.