TDAE aromatic oil preference for polymer blends: An analysis of S-SBR, BR, and miscible S-SBR/BR systems

Abstract

This study assesses the impact of Treated Distillate Aromatic Extract (TDAE) oil, at concentrations of 0–20 parts per hundred rubber (phr), on the glass transition temperature (T g ) of High Vinyl/Low Styrene Styrene-Butadiene Rubber (HVLSS-SBR), polybutadiene rubber (BR), and their blends with weight ratios of 70/30 and 50/50. Using Dynamic Mechanical Analysis, Broadband Dielectric Spectroscopy, and Positron Annihilation Lifetime Spectroscopy, we found that TDAE modifies T g and fractional free volume (F v ) differently across materials. In HVLSS-SBR, TDAE reduced T g by approximately 10 °C and increased F v by 0.8 %. In BR, TDAE raised T g by 5–7 °C without altering F v . The 70/30 blend showed no T g change but a 0.6 % F v increase. For the 50/50 blend, one Havriliak-Negami equation indicated a T g rise of 2–3 °C and a 0.4 % F v increase. A two-equation analysis revealed a 6 °C T g increase and 0.9 % F v boost in the BR-rich phase, versus a 2 °C rise and 0.3 % F v uptick in the HVLSS-SBR-rich phase. The sequence of compatibility, influenced by TDAE, is crystalline BR > amorphous BR > HVLSS-SBR >70/30 blend >50/50 blend. This study provides valuable insights into the behavior of TDAE oil in rubber blends and can serve as a basis for further research in this field.