Replacement of Carbon Black by Renewable Fillers in Natural Rubber

This study addresses environmental concerns surrounding resource depletion and carbon emissions by investigating sustainable fillers in natural rubber compounds. The primary aim is to reduce reliance on the non-renewable carbon black filler. Various renewable fillers are introduced as partial or whole substitutes for carbon black. Initial inferior in-rubber properties arise due to lower surface area and differing chemistry of the renewable fillers. To enhance performance, promising calcium carbonates and lignin-filled compounds are modified using in-situ coupling agents. Incorporating alpha lipoic acid and a titanate agent improves processing and mechanical properties, even yielding carbon black-comparable performance. Silane coupling agents improved the lignin compounds' hardness and rebound resilience but showed diminished elongation and tensile strength.