Kinetics of poly(ethylene terephthalate) fiber glycolysis in ethylene glycol

Abstract

The glycolysis of poly(ethylene terephthalate) (PET) fiber is carried out using excess ethylene glycol (EG) in the presence of Zn/Al mixed oxides. The effects of the weight ratio of EG to PET, the weight ratio of catalyst to PET, reaction temperature and reaction time on the yield of bis(hydroxyethyl terephthalate)(BHET) are investigated. The conversion of PET and yield of bis(2-hydroxyethyl terephthalate) (BHET) reach about 92.6 % and 82 % under the optimal experimental conditions. The properties of the glycolysis products have been characterized by scanning electron microscopy (SEM), infrared spectroscopy analysis (IR), differential scanning calorimeter (DSC), thermogravimetric analysis (TG) and high performance liquid chromatography (HPLC). An evolution of the glycolysis reaction is proposed. In addition, the kinetic of PET fiber is investigated. The results indicate that this glycolysis process is a first-order kinetic reaction and the activation energy is 79.3 kJ/mol, which is lower compared to the same reaction process using PET flake from the soft drink bottle.

PET glycolysis optimization using ionic liquid [Bmin]ZnCl3 as catalyst and kinetic evaluation

“…The apparent activation energy for the process of glycolysis with the catalyst [Bmin]ZnCl 3 , calculated on the straight line slope in Arrhenius plot (Figure 8) was 36.49 kJ/mol. The calculated result of the apparent activation energy is well lower compared to the data reported in the literature (Table 4), the energy values 53.8 kJ/mol and 56.4 kJ/mol for 1-butyl-3-methylimidazole acetate combined with zinc and copper acetates respectively [9] , 58.53 kJ/mol with 1-butyl-3-methylimidazole acetate [23] , 79.3 kJ/mol with zinc and aluminum oxides mixture [24] , 85 kJ/mol with zinc acetate [25] , 92 kJ/mol with zinc (acetate and stereate) salts [26] and 108 kJ/mol without catalyst [25] .…”

Reactive Extrusion of Polyethylene Terephthalate Waste and Investigation of Its Thermal and Mechanical Properties after Treatment

“…It has good tensile strength, chemical resistance, and suitable thermal stability. Huge quantities of PET are used in the production of food packaging materials and water bottles [9,10]. With the enormous development and usage of PET, a large fraction of PET gets added to the waste system on a yearly basis.…”

Ultrasmall CeO2 Nanoparticles with Rich Oxygen Defects as Novel Catalysts for Efficient Glycolysis of Polyethylene Terephthalate

“…Meanwhile, CeO 2 −2.7 nm exhibits the highest rate constant in the glycolysis of PET (0.02446 min −1 ), which are caused by the rich oxygen defects and Ce 3+ content that will be further discussed in the following parts. In addition, the ultrasmall CeO 2 NPs with good dispersity (zeta potential = 47.6 mV) and the highest specific surface area of 155.6 m 2 /g (Table 1) can easily enter the porous structure on the outside surface of PET during glycolysis, 32 decrease the mass transfer resistance, and accelerate the complete contact between reactants and catalysts, which could contribute to a higher catalytic activity in the reaction.…”