Effect of matrix modification and fiber surface treatment on the properties of basalt fiber reinforced polypropylene composites

With a focus on sustainable natural fiber reinforced polypropylene composites in varied industries like automotive and aerospace, this study investigates the impact of matrix modification and surface treatment of basalt fibers on the thermomechanical properties of basalt fiber reinforced heterophasic polypropylene composites. Polypropylene matrix modification was achieved by adding maleic anhydride grafted polypropylene (PP-g-MA), resulting in composites that exhibited a 133 % improvement in the tensile strength and 256 % improvement in the tensile modulus at 30 % fiber weight compared to neat polypropylene. The short basalt fibers underwent a silane treatment; However, the thermal treatment used to strip the default manufacturer's sizing resulted in a fluffy fibres texture, which led to agglomeration and feeding issues during processing. Although the silane treatment helped establish a better fiber-matrix interphase, no significant improvement in tensile strength was observed. However, the tensile modulus saw a 343 % improvement at 30 % fiber weight as compared to neat polypropylene. Resizing short basalt fibers following fiber recovery at the end-of-life stage of the composite would be challenging due to the fluffy nature of the fibers. Therefore, any fiber treatment should be done at the initial fiber manufacturing stage, and surface treatment at later stages requires detailed study.