The use of intermediates obtained from aminoglycolysis of waste poly(ethylene terephthalate) (PET) for the synthesis of water-reducible alkyd resin

Abstract

In this study, depolymerization products obtained from an aminoglycolysis reaction of postconsumer poly(ethylene terephthalate) (PET) bottles were used for the synthesis of water-reducible alkyd resins for the first time. We also aimed to reduce the amount of amine using aminoglycolysis products of PET having amine end groups for the neutralization of alkyds in this work. Alkyds formulated to have an oil content of 50% were prepared with glycerine (G), ethylene glycol (EG), fatty acid (FA), and phthalic anhydride (PA) or aminoglycolysis depolymerization products (ADP). The “K alkyd constant system” was used for the formulation calculations of the alkyd resins. The K constant was 1.1 and the ratio of basic equivalents to acid equivalents (R) was 1.15. Physical and chemical film properties and thermal degradation stabilities of these alkyd resins were investigated. According to the results of surface coating tests, the properties of the waste PET-based alkyd resins were found to be compatible with the properties of the reference resins. In addition, thermal degradation stabilities of the water-reducible alkyd resins prepared by ADP were better than that of the reference resin. As a result, we concluded that aminoglycolysis products of waste PET are suitable for manufacturing water-reducible alkyd resins. Furthermore, the amount of amine used for the neutralization stage of preparing water-reducible resin was reduced by 50% using aminoglycolysis products having an amine end group.