From Waste to Schiff Base: Upcycling of Aminolysed Poly(ethylene terephthalate) Product

Recycling plastic waste into valuable materials is one of the contemporary challenges. Every year around 50 million tons of polyethylene terephthalate (PET) bottles are used worldwide. The fact that only a part of this amount is being recycled is putting a burden on the environment. Therefore, a technology that can convert PET-based waste materials into useful ones is highly needed. In the present work, attempts have been made to convert PET-based waste materials into a precursor for others. We report an aminolysed product (3) obtained by aminolysis reaction of PET (1) with 1,2 diaminopropane (DAP, 2) under solvent and catalytic free conditions. The highest amount of monomeric product was obtained upon heating the mixture of diamine and PET at 130 °C. The resulting aminolysed product was then converted to a Schiff-base (5) in 25% yield. The chemical structure of the synthesized compounds was confirmed using multi-spectroscopic techniques. The results of this study will be a valuable addition to the growing body of work on plastic recycling.