Tuning the low rolling resistance, wet grip, and heat build-up properties of tyre tread formulations using carbon black/thermally exfoliated graphite hybrid fillers

Ecofriendly green tyre tread compounds were developed with low rolling resistance, low heat buildup, and improved wet grip properties. A standard formulation of natural rubber (NR) and butadiene (BR) with 50 phr carbon black was prepared in a brabender plasticoder. Based on the processability, successful reduction of carbon black and aromatic oil content was done up to a minimum value of 32 and 3 phr respectively. Partial replacement of graphite with carbon black was done to achieve the optimized formulation. A binary filler system with 10 phr graphite and 22 phr carbon black was optimized based on the mechanical properties and further addition of graphite leads to reduction in properties due to agglomeration. To enhance the properties further, the graphite was thermally treated to get an exfoliated structure which can significantly improve the area of the filler/matrix macromolecules interface. This ultimately had a positive impact on targeted properties. A sudden thermal shock for 15 min at various temperatures ranging from 400 to 550? was given and prepared the optimized binary formulation and evaluated the properties. Excellent results in terms of low rolling resistance (0.039) and heat build-up (18?) were recorded for final formulation. The flex fatigue resistance was enhanced and the thermal stability improved by 29?.