New UV Curable Acrylated Urethane-Oligoesters Derived From Poly(Ethylene Terephthalate) PET Waste

Abstract

The glycolysis products of polyethylene terephthalate (PET) waste represent a potential source for many value-added products that contain terephthalate repeating units in their backbones. Terephthalate repeating units were not attained directly from terephthalic acid due to its high melting point in addition to its tendency to sublime before it reacts. Glycolysis of PET provides an excellent solution for recycling polymer waste and constitutes a substantial starting material for manufacturing materials with high mechanical stress, such as unsaturated polyesters and polyurethane products. In this study, PET was first depolymerized by glycolysis, and glycolyzed products were then dimerized by reaction with toluene di-isocyanate TDI with half equivalence of their hydroxyl groups for the purpose of inserting urethane blocks into the oligomer structure. The remaining half equivalence of terminal hydroxyl groups was modified into acrylate groups by an acrylation reaction. The acrylated oligo urethane ester products were crosslinked with different co-monomers and tested for UV curability and mechanical properties, and they showed outstanding results.