ABSTRACT

This effort focused on events taking place during the co-vulcanization of rubber compounds comprising ground rubber particles (GRPs) collected from end-of-life tires and assumed to be responsible for the commonly observed losses in key physical properties. Of greatest impact was the diffusion of cure ingredients (sulfur and cure accelerators) into the GRPs, causing additional crosslinking, low interfacial adhesion between the GRPs and the host matrix, and the formation of failure-promoting stiffness gradients. Their involvement and overall impact on failure properties were also assessed via finite element analysis. Based on this more detailed understanding, new methods were identified and tested in laboratory experiments that suggest successful novel GRP-based recycling pathways involving labyrinthine materials such as graphene oxide. These methods seem to offer promise compared with the merit of pyrolysis, which only recently is undergoing vigorous evaluations by the tire industry.