Green Tire Tread Compounds with Improved Dispersion Based On Silica-Reinforced Epoxidized Natural Rubber

With growing concerns about climate change and the cost and long-term availability of oil supplies, there is increasing pressure for products such as tires to be manufactured in part or entirely from renewable materials, as well as for the energy consumption and carbon footprint over the life cycle of the tire to be minimized.  This can be achieved in tire treads by using the renewable polymer, epoxidized natural rubber (ENR-25, with 25% epoxidation), reinforced with silica.  As well as delivering lower rolling resistance, and hence reduced fuel consumption, silica-filled ENR tire treads have the added benefit of providing enhanced wet traction, when compared with treads based on silane-coupled silica-filled synthetic rubbers (solution SBR/BR blends).  Micro-dispersion of silica in ENR has been shown to be exceptional.  The influence of the mixing procedure, process oil, moisture content and other additives on the macro-dispersion achieved during mixing of ENR/silica compounds has been studied.  The macro-dispersion has been significantly improved, resulting in improved tire tread properties, in particular markedly better abrasion resistance.