Aminoglycolysis of Waste Poly(ethylene terephthalate) With Diethanolamine and Evaluation of the Products as Polyurethane Surface Coating Materials

Aminoglycolysis and simultaneous hydrolysis-aminoglycolysis of poly(ethylene terephthalate) (PET) wastes by diethanolamine (DEA) was attempted in the presence of xylene, with the aim of obtaining intermediates containing both hydroxyl and carboxyl end groups, which could be employed in polyurethane surface coatings. Aminoglycolysis and simultaneous hydrolysis-aminoglycolysis reactions were carried out with the catalysis of zinc acetate (ZnAc) at high temperatures and relatively high pressures. Depolymerization products were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimeter (DSC). To prepare polyurethane surface coating films, the depolymerization products were reacted with 1,4 butanediol (BDO) and toluene diisocyanate (TDI) in the presence of dibutiltin dilaurate (DBTDL) catalyst and pyrogallol inhibitor. After the films prepared, the physical properties such as hardness, drying degree, adhesion, and impact resistance of these films were investigated. The intermediates yielded from medium to very hard coatings with excellent adhesion and having medium to very good drying degree. POLYM. ENG. SCI., 51:746-754,2011. (C) 2011 Society of Plastics Engineers