A review on reinforcement of natural rubber by silica fillers for use in low-rolling resistance tyres

High dispersion silica has recently become the preferred alternative to carbon black for low rolling resistance tyres. However, the combination of natural rubber with silica and a coupling agent remains a challenge, but also offers a tremendous potential for reduction of energy consumption of transport. This paper gives an overview of the recent studies on silica reinforcement in natural rubber (NR) and its importance in tyre technology. Recent work on optimisation of the mixing process of silica in NR compounds and the influence of non-rubber constituents such as proteins on silica reinforcement are highlighted. The utilisation of modified NR such as epoxidised NR, and deproteinised NR are the methods of choice to enhance the compatibility between NR and silica, as well as to minimise the interference of proteins with coupling agents. A better understanding of the problems encountered with NR/silica systems will facilitate the further development of silica technology for NR, especially for use in highly filled silica tyre compounds