Optimization of TiO(acac)2 for efficient catalytic alcoholysis of waste PET using response surface methodology

Abstract

Acetylacetone titanium oxide (TiO(acac)₂) was synthesized from acetylacetone and isopropyl titanate via a one-pot method. The catalyst's structure and morphology were characterized and analyzed using FT-IR, UV–vis, XRD, SEM, and laser particle size analysis. The prepared acetylacetone titanium oxide was used for the alcoholysis reaction of polyethylene terephthalate (PET), and the yield of bis(hydroxyethyl) terephthalate (BHET) obtained from the alcoholysis reaction was taken as the index. The optimal conditions for the alcoholysis reaction were determined using response surface methodology: 3 g of PET, a catalyst dosage of 0.467%, a temperature of 200.5 °C, a time of 3.77 h, and 13.50 mL of ethylene glycol, with a BHET yield of 96.41%. The model had good reliability. Finally, the reaction mechanism was speculated, and the catalyst was compared with other catalysts. The TiO(acac)₂ catalyst has a good application prospect.