The effect of feldspar and kaolin on mechanical performance of SBR/LDPE composites

Background: Feldspar and kaolin was ball milled at 320 rpm for hours with the aid of a dry grinding agent. Both minerals were combined with inorganic salt namely sodium chloride as a grinding agent. The grinding agent and mineral were mixed at the ratio of 1:1. Results: The application of such grinding agent led to effectively reduce the particle size in a short time. The mineral materials were viewed under a scanning electron microscope (SEM) before and after grinding. SEM graphs revealed that a significant reduction in average particle size was recorded for both minerals. The reduction percentage for kaolin was about 82%, and in the case of feldspar, it was about 93%. The BET surface area of both minerals increased after milling. The potential of the ground filler on the tensile properties of low-density polyethylene/styrene butadiene rubber (LDPE/SBR) composites has been reported. Conclusions: The ball milling of the raw fillers in the presence of inorganic salt was found to be able to reduce the particle size of the fillers significantly in a short time. The application of dry grinding agent did not display any agglomeration or cold welding between the mineral particles as evidenced by the SEM images. The incorporation of the ground filler into LDPE/SBR composites showed a positive impact on the tensile strength at the cost of elongation at break except for the feldspar.