Toughening and reinforcing waste polypropylene with POE/nano-SiO2 under elongational flow

Due to the white pollution, the recycling of waste plastics has attracted more and more attention. In this research, waste polypropylene/Ethylene-octene elastomer/nano-SiO2 composites (wPP/POE/SiO2) were melt-blended using an Eccentric Rotor Extruder (ERE) dominated by elongational flow field and a Torque Rheometer (TR) dominated by shear flow field, respectively. The micromorphology, mechanical, crystallization, thermal and rheological properties of wPP/POE/SiO2 blends were studied. Compared to the blends fabricated by TR, the wPP/POE/SiO2 blends with different compositions fabricated by ERE showed higher tensile strength, flexural strength, and modulus. Particularly, without sacrificing the tensile strength, the notched impact strength of the wPP/POE/SiO2 blends fabricated by ERE increased to 13.53 kJ/m(2), a factor of 3 times larger than that of neat wPP. The enhancement of impact strength of the wPP/POE/SiO2 blends fabricated by ERE could be ascribed to the good dispersion of POE under elongational flow and the increase of PP crystallinity. The finding from this work provides an efficient way to recycle wPP.