Testing and Evaluation of Rubber-base Composites Reinforced with Silica Sand

Abstract

In this study, natural rubber (NR) was reinforced with the unique composition of Jordanian silica sand at different loadings (10, 30, 50, and 75 pphr) and different particle sizes (10, 25, 45, and 75 μm). Several tests, such as hardness, tensile strength, elongation at break, compression set, compression stress-strain, and density are conducted to evaluate this composite according to the international standards. The results showed that, although the particle size for each loading is directly proportional to the hardness, the worst results are observed for the products of 75 pphr loading and 75 μm particle size. The tensile strength is inversely related to the particle size of the filler and gives the highest strength when filling with 10 pphr among other filling loadings. The elongation at break of natural rubber reduced by increasing the loading and decreasing the particle size. The results of compression set showed that the best behavior was for the product of 10 pphr and 10 μm particle size. The compression stress is directly related to the loading, especially for small particle sizes. The elastic modulus increased with the increase of loading and the increase of particle size. The density test showed that the silica filler has no significant increase in the density of rubber especially for small particle size fillers. Comparing the studies of properties of the manufactured rubber-base composites in this investigation with those achieved in other research works, it is found that they are superior especially for hardness, tensile strength, and compression set properties and density.