Biopolypropylene-Based Wood Plastic Composites Reinforced with Mango Peel Flour and Compatibilized with an Environmentally Friendly Copolymer from Itaconic Acid

Abstract

This work reports on the successful development of biopolypropylene/mango peel flour (bioPP/MPF) composites using extrusion and injection molding processes. The compatibility between bioPP and MPF is improved through the use of PP-g-IA (3 phr) as a compatibilizer (which is prepared by reactive extrusion REX) and dicumyl peroxide (DCP) (1 phr) as a cross-linker. The mechanical, morphological, thermal, thermomechanical, chemical, colorimetric, water absorption, and flowability properties are characterized and analyzed. The results show that MPF (30 wt %) compatibilized with PP-g-IA and DCP increased the stiffness of bioPP in terms of Young's modulus values. Elongation at break also shows very promising results, with a maximum value of almost 30% for the bioPP/MPF/PP-g-IA/DCP sample. PP-g-IA and DCP seem to exert a synergetic effect. Thermal stability is also improved as a result of these additives, as well as crystallinity, which is increased due to an heterogeneous nucleation phenomenon, enhanced by a higher dispersion of MPF particles in the matrix. Moreover, the excellent mechanical results are verified in FESEM images, where a very narrow gap between the MPF particles and the bioPP matrix is appreciated.