The Effect of Silane on the Curing Characteristics and Mechanical Properties of Natural rubber/Nanoclay/Calcium Carbonate Nanocomposite

To enhance the mechanical properties of the rubber products, reinforcing agents are used. Carbon black (CB) is the most important reinforcing agent used in the rubber industries. The use of nanoparticles to reinforce rubbers has also become a topic of interest these days. However, dispersion of nanoparticles in rubbers is a challenge. In this study, nanocomposites based on natural rubber (NR)/carbon black containing clay nanoparticle and calcium carbonate were prepared. Mixing was carried out on a two roll-mill and silane as a coupling agent and compatibilizer was employed to improve the dispersion of nanoparticles. The effects of silane content on the curing characteristics and mechanical properties of the samples were investigated. The curing rheometer graph illustrated that by increasing the silane up to a specific amount, the scorch time and technical curing time increased and then they decreased. The mechanical tests showed the same trend of variation for the tensile strength, modulus and hardness. The increase in mechanical properties whit silane was attributed to the compatibilizing effect of silane.