Aminolysis of poly(ethylene terephthalate) waste for recovery of value added comonomeric product

Reaction of poly(ethylene terephthalate) waste (PETW) powder with hydrazine monohydrate (HMH) using 0.003mol lead acetate as a catalyst was carried out in a batch reactor at 339K and at atmospheric pressure. Reactions were undertaken with various particle size ranges from 50-512.5 mum, and reaction time from 30-240 min at the interval of 30 min. Terephthalohydrazide (TPHD) and ethylene glycol (EG) were recovered during aminolysis of PETW. To increase the PETW conversion rate, external catalyst (lead acetate) was introduced during the reaction. The reaction product (TPHD) was deposited on the surface of unreacted PETW that was removed from the surface by introducing dimethyl sulfoxide (DMSO). Moreover, to improve the reaction rate cyclohexylamine (CHA) was introduced during reaction. Aminolysis of PETW was proportional to the reaction time. Depolymerization of PETW was inversely proportional to the particle size of PETW. Analyses of value-added products (TPHD and EG) as well as PETW were undertaken. A kinetic model was developed and experimental data simulated with it that were consistent with the model. Thermodynamic study was undertaken as this is required during transfer of laboratory data through the pilot plant for commercialization.