Using bio-based plasticizers, alternative rubber

Plasticizers such as treated distillate aromatic extracts and aromatic oils commonly are used in tread compounds because of their chemical compatibility and ability to improve rubber processing. Alternative sources to these petroleum- derived plasticizers, such as oils extracted from crops, were evaluated in model tread compounds. Select bio-based oils with varying fatty acid compositions and functionality were used to replace part of the petroleum oil and compounded into silica-based tread formulations. These bio-based plasticizers were evaluated in rubber compositions with 80/20 blends of solution styrene-butadiene rubber and natural rubber, as well as blends with an alternative bio-derived rubber, guayule. Effects of these bio-based plasticizers and rubber on the material's cure kinetics and key physical properties are discussed. Dynamic mechanical thermal analysis results are correlated to on-vehicle performance predictors for rolling resistance and traction by assessing tangent delta in various temperature regions. This study shows that use of bio-based materials provides a promising alternative to standard oil and rubber matrices, as supported by comparable mechanical properties and performance predictors. Key technical challenges and the potential future outlook for using sustainable raw materials in tread compounds are discussed.