The Influence of Different Types of Rubber on Curing Behaviour and Dynamic Properties of Rubber Compound

Abstract

The aim of the present work is to investigate the effect of the different types of rubber on cure characteristics. The paper also explores the dynamic properties of these rubbers. The curing behaviour of the rubber compound is the main consideration for the rubber moulding process maker, which govern the process and properties of the rubber product. The dynamic properties are another factor that needs to take into account as it is the important properties especially in designing an anti-vibration component. Three types of rubber were used includes natural rubber (NR), styrene butadiene rubber (SBR) and chloroprene rubber (CR). All rubber compounds were prepared based on semi-efficient (semi-EV) sulphur vulcanization system. These compounds were mixed by melt mixing on a two-roll-mill lab scale machine. The cure characteristics were analysed using the Moving Die Rheometer (MDR 2000). The results obtained show that SBR presented higher torque different (MH-ML) value followed by NR and CR. The hardness of the rubber compound showed a similar trend as torque different result. The dynamic properties; static stiffness, Ks and dynamic stiffness, Kd were tested using the Selvopulser Testing machine. For Kd value, the test was reported on the frequency of 100 Hz. The static stiffness, Ks shows a similar trend as the torque different and hardness results; SBR>NR>CR however, for dynamic stiffness, Kd value trend has shown significant changed to SBR>CR>NR. This is due to the bond breakage in a rubber chain also known as Payne effect. In conclusion, the Kd, torque different and hardness are correlated to the rubber molecular weight, meanwhile, for Ks is much more related to interaction of molecular structure in rubber compound (Payne effect).