The properties of hardness and swelling of styrene butadiene rubber/silica/oleamide composites

Abstract

Abstract This paper reports the results of the effects of oleamide addition on hardness, as one of the mechanical behaviours, of styrene butadiene rubber/silica (SBR/silica) composite. The base SBR was compounded with silica, as a reinforcing filler, and others compounding chemicals. The silica was compounded into the rubber matrix at 30 phr and others compounding chemicals were added based on the semi-efficient rubber compounding formulation. The compounding has been done using opened two-roll mills. Oleamide was added to the SBR/silica to improve the rubber-to-filler interaction and the mechanical properties of the SBR/silica composite. The oleamide was a lab-synthesizing chemical and was added into the SBR/silica with 4 different concentrations (2, 4, 6 and 8 phr). The SBR/silica compounds with and without oleamide were vulcanized at 150 °C using a typical cure meter. From the results; it was noticed that the hardness of the SBR/Si composite was increased as the oleamide was added to the SBR/Si compound. It was considered that the hardness improvement was attributed to the result of crosslinks improvement of the NR/silica/oleamide composites. The additions of the oleamide convert the rubber composites into more resistance to swelling. A greater degree of crosslinks would increase the swelling rejection/resistance but decrease the interpenetration of the toluene solution to the rubber composites. The oleamide acted as an additive which improved the properties of swelling and hardness of the SBR/Si mixtures/compounds and, a 2 phr of oleamide addition was the optimum concentration for the SBR/Si compound.