Enhancing mechanical properties of high-density polyethylene/polydopamine-modified basalt fiber composites via synergistic compatibilizers

The mechanical properties of polymer-based composites are generally determined by the interfacial adhesion between the inorganic component and the polymer itself. In this work, high-density polyethylene (HDPE) composites were prepared with polydopamine(PDA)-modified short basalt fibers (D-BF) as an inorganic filler, in which the interface between HDPE and D-BF was mediated by maleic anhydride-grafted polyethylene (PE-g-MAH) and maleic anhydride-grafted poly(ethylene-co-octene) elastomer (POE-g-MAH). The adding mass ratio of both the compatibilizers had a significant effect on the mechanical properties of the prepared HDPE/D-BF composites. When total 5 wt% of both PE-g-MAH and POE-g-MAH with a mass ratio of 1/3 was introduced, the tensile strength and elongation at break of the composite containing 2.5 wt% D-BF reached 53.7 +/- 0.8 MPa and 1174 +/- 17%, respectively, about 73% and 157% higher than those of the pristine HDPE. Therefore, this work demonstrated a feasible way to prepare polymeric composites with high strength and high toughness via the dual-compatibilizer and PDA modification of the fillers.