Ceramic Waste-Based Natural Rubber Composites: An Exciting Way for Improving Mechanical Properties

Large amounts of fired ceramic waste produced in ceramic industry do not have a proper method to reuse and mainly thrown away into landfills since fired ceramics have already been sintered and thus their utilization as a raw material is limited. However, these solid wastes have a major environmental and economic concern. Thus, a proper management of such solid wastes is eminent. This research is dedicated to evaluating the possibility of using such ceramic waste as a low-cost filler material in the manufacture of natural rubber based composites. Ceramic particles smaller than 125 μm were selected initially for the preparation natural rubber based composites. For the latter part of the study, particles in sub-micrometer length scales were used. Elemental analyses and composition of the phases of the ceramic particles were determined by X-ray fluorescence and diffraction respectively. The average particle size was characterized by scanning electron microscope (SEM). The surfaces of the sub micrometer size ceramic particles were modified using Silane69 coupling agent. The surface modification was confirmed by Fourier-transform infrared spectroscopy, thermo gravimetric analysis and SEM coupled with energy-dispersive X-ray spectroscopy. Natural rubber based composites were prepared with different levels of ceramic filler loadings. The mechanical properties of the composites such as hardness, resilience, compression set, abrasion volume loss and tensile properties were evaluated. These properties of the composites were compared with those of the composites prepared according to the same formulation except the ceramic filler (control). The composites were found to have an exciting enhancement of mechanical properties with respect to the control. The mechanical property improvement is higher when the ball milled sub-micrometer size ceramic filler is used and it is even better when surface modified ceramic particles are used.