Waste PET Chemical Processing to Terephthalic Amides and Their Effect on Asphalt Performance

A chemical recycling approach of mixed PET was demonstrated here that provides a mechanism by which PET waste can be efficiently recovered and repurposed to value-added products. The approach utilizes aminolysis of PET with a variety of amine nucleophiles, generating a small library of terephthalic amides with distinct structures, such as polar, nonpolar, and lipophilic. In order to probe the value of these products, the terephthalic amides were added to road-grade asphalt binder at 5 wt %, and the fresh resulting composite was evaluated. Specifically, rutting and fatigue characteristics as well as thermomechanical and creep performance were characterized and found to be improved by the inclusion of these additives by as much as 18%. In this work, additives made from deconstructed PET wastes were shown to improve the performance properties of asphalt at a variety of environmental conditions. It is important to note that the asphalt binder utilized in this work was a commercial product already optimized for road conditions, not the raw bitumen; perhaps higher performance metrics could be obtained with virgin bitumen.