(Mg-Zn)-Al layered double hydroxide as a regenerable catalyst for the catalytic glycolysis of polyethylene terephthalate

(Mg-Zn)-Al layered double hydroxide (LDH) was prepared by the coprecipitation method at low super saturation conditions. The prepared (Mg-Zn)-Al LDH was analyzed using XRD, FTIR, N2 adsorption-desorption, TGA and DSC, confirming the formation of pure LDH phase. The extent of polyethylene terephthalate (PET) degradation by the glycolysis process was studied using the prepared (Mg-Zn)-Al LDH. The glycolysis process was optimized in terms of catalyst concentration, temperature, time, ethylene glycol dosage. Under the optimal conditions of 1.0 wt.% of catalyst with 20 g of ethylene glycol (EG) in the presence of 2.0 g of PET at 196 °C after 3 h of glycolysis, complete PET conversion was achieved and the yield of bis (2-hydroxyethyl) terephthalate (BHET) reached 75%.