Valorization of polyethylene terephthalate wastes to terephthalamide via catalyst-free ammonolysis

Valorization for the recycling of polyethylene terephthalate (PET) wastes has garnered significant attention. An innovative one-step approach, devoid of catalysts and solvent, was developed for the ammonolysis of PET to terephthalamide (TP) at mild temperatures (40–120 °C). The study extensively explored and discussed the impacts of key process parameters such as temperature, reaction time, material ratio, stirring speed, and various PET-containing materials. The reaction conditions were further optimized via Response Surface Methodology. The results demonstrated proposed ammonolysis technique facilitates the straightforward recovery of high TP yield (>90 mol%) and purity (>95 %), establishing an effective avenue for TP production through PET waste valorization.