Magnetic polypropylene composites with selectively localized reactive nano-Fe3O4 in toughener of POE-g-MAH: Towards super toughness, high flexibility and balanced strength

Herein, a new magnetic super-tough polypropylene (PP) composite was developed via one-step melt blending with maleic anhydride grafted ethylene-octene copolymer (POE-g-MAH) and reactive nano-Fe3O4. The reactive nano-Fe3O4 with polyamide (PA) tails (PA-Fe3O4) was prepared by in situ ring-opening polymerization PA with amino-modified Fe3O4. By regulating the ratio of POE-g-MAH to PA-Fe3O4, PA-Fe3O4 nanoparticles can selectively and uniformly distribute in the POE-g-MAH phase, reinforcing the POE-g-MAH phase and reducing its processing viscosity synchronously as a new plasticizer and compatibilizer. Meanwhile, a cocontinuous morphology was formed in the PP/POE-g-MAH/PA-Fe3O4 composite at a low elastomer content, contributing to the dramatically enhanced toughness of the PP matrix without deteriorating the processing flowability. In particular, adding 4 wt% PA-Fe3O4 into PP/POE-g-MAH (weight ratio: 80/20), the notched Izod impact strength of the composite reached 74.2 kJ/m2, which was enhanced by approximately 247%. In addition, these super-tough PP composites have excellent flexibility and room temperature soft magnetic performance. This study provides a novel and feasible strategy to fabricate magnetic polymer composites with excellent mechanical properties via manipulating the morphology of the composites.