A novel bio - based antioxidant derived from waste coconut shell for enhanced thermo- oxidative stability in carbon black filled styrene butadiene copolymer

This study delves into the potential of natural phenolic compounds sourced from waste coconut shells as a safe and eco-friendly alternative to the hazardous N-1,3-dimethylbutyl-N-phenyl-p-phenylenediamine, also known as 6PPD. The objective is to utilize these compounds as an antioxidant in styrene butadiene rubber (SBR). The efficacy of the novel antioxidant was assessed through thermal and ozone aging studies. Composites with coconut shell extract (CSE) demonstrated remarkable mechanical properties, boasting a 35% increase in tensile strength and a 44% increase in elongation at break. Although the retention of mechanical properties after thermal aging was marginally lower than 6PPD, as revealed from the aging coefficient and the values of the protection factor, CSE displayed lower leachability, rendering it a sustainable substitute for 6PPD. Therefore, CSE opens up new avenues of sustainable replacement of 6PPD with the advantage of its ability to act as an antioxidant and overall enhancement in mechanical properties.