Devulcanized rubber could be a valuable material feedstock to help in the manufacture of sustainable rubber products. However, the differences in the chemistry and structure of devulcanized rubber have limited industrial uptake. This work demonstrates how devulcanization affects the concentration and ratios of mono-, di-, and polysulfidic cross-links. These residual cross-links make devulcanized rubber chemically dissimilar from virgin rubber, affecting (re)vulcanization. The hypothesis that the sulfur rank of revulcanized material can be modified by the sulfur/accelerator ratio was evaluated by two different cure packages. Despite substantial differences in the accelerator/sulfur ratio, both recycled rubber compounds favored the formation of polysulfidic cross-links.
© 2024 The Authors. Published by American Chemical Society.