Properties of natural rubber filled with ultra fine acrylate rubber powder

Abstract

Properties of natural rubber (NR) filled with various loadings of ultra-fine vulcanized acrylate rubber powder (ACMP) were investigated. ACMP loading was varied from 0 to 20 phr and, after compounding, the compound properties were determined. Results reveal that increasing ACMP loading leads to improved processability, as evidenced by the reduction of both mixing energy and Mooney viscosity. ACMP, however, has negative effect on cure, that is, both scorch time and optimum cure time are prolonged while the state of cure is reduced with increasing ACMP loading. Due to the reinforcing effect of the fine ACMP particles, both modulus and hardness are found to increase consecutively with increasing ACMP loading. The tensile strength is also found to improve with increasing ACMP loading up to 10 phr. However, due to the cure retardation effect and the high thermoplastic nature, the presence of ACMP causes deterioration of elasticity. As ACMP is highly polar and fully saturated, the addition of ACMP enhances the resistance to oil and thermal aging of the NR vulcanizate. Significant improvement of thermal aging resistance is found when 10 phr or more of ACMP is added. © The Author(s), 2010.