The influence of non-toxic extender oil on SBR performances

The increasing concern about the toxicity of highly aromatic oil (DAE) has been the incentive to develop types of E- SBR and S-SBR containing non-toxic (safe) extender oils. The main objective has been to develop replacements for the two workhorses of the tyre industry, namely SBR 1712 and 1721. Experimental activities have been carried out to investigate the effect of safe oils on rubber processability and vulcanizate properties and to provide information to help rubber technologists reformulate their compounds for equivalent properties. In a first step, based on iso-Tg concepts, two E-SBR types have been developed to replace SBR 1712 and their main properties have been evaluated. In a second phase TDAE and MES oil effects have been analysed with the aim of replacing the aromatic oil extended S-SBRs that are widely used by the tyre industry. In a third phase an investigation of safe oil extended emulsion SBRs suitable to replace standard SBR 1721 was accomplished. It confirmed that with MES oil a S-SBR with an appropriate microstructure would probably be required to give the best match. On the contrary extension with TDAE oil would be easier and would eventually imply only a minor change in microstructure.