Abstract
The aim of this study was to investigate the influence that different fatty acid zinc salts had on the rheological, curing and mechanical properties of natural rubber based composites filled with silica and containing bi-functional organosilanes in the presence or absence of zinc oxide. The results demonstrated that the combination of zinc oxide and zinc soaps had a strongly pronounced anti-reversion effect. The absence of reversion in the cure curves of the rubber compounds comprising a combination of zinc oxide, stearic acid and zinc soaps, results in retention of their mechanical properties, even after overcure.