Chemical Recycling of PET by catalyzed aminolysis and its application as a hardener for epoxy coating

Due to the widespread application of polymers, waste management is becoming elusive and a threat to the polymer industry, both manufacturing and processing. One commonly used polymer is polyethylene terephthalate (PET), considered environmentally harmful due to its substantial presence in waste streams and its resistance to natural degradation. Chemical recycling is the most suitable solution for dealing with this, as polymers are recycled into their starting material and used in various applications. Aminolysis of PET offers an alternative approach that can be conducted under less stringent conditions, yielding valuable chemicals. In this work, we depolymerized PET into an oligomeric product using 4,7,10-trioxa-1,13-tridecanediamine as an aminolysis agent. The resulting oligomer, containing amine functionality, was investigated for its potential as a curing agent for epoxy resin in coating applications. The aminolyzed product demonstrated enhanced performance, resulting in epoxy coatings with superior thermal stability, mechanical strength, and chemical resistance compared to traditional hardeners. These properties were rigorously tested and validated according to ASTM standards. Additionally, the direct utilization of the product obtained without filtration or separation provides a cost-effective solution. Our findings highlight a promising approach to PET recycling, providing a sustainable solution for waste management and a novel application for high-performance epoxy coatings.