Organic/Inorganic Nanosilica Support Role in the Recovery of Terephthalic Acid From Poly (ethylene terephthalate) Wastes

In this report the efficiency of organically modified nanosilica namely, γ-glycidoxy propyl trimethoxy silane / diethanol amine (GDS) was evaluated in the recovery of terephthalic acid from poly (ethylene terephthalate) wastes received from used soft-drink bottles. In this study, organically modified nanosilica used as the solid support, diethylene glycol (DEG) as the solvent and sodium hydroxide as the catalyst and the support performances was examined in detail and the results were compared with unsupported reaction. Results showed that (GDS) delivered good performance as the reagent and solid support in depolymerizing of poly (ethylene terephthalate) to the terephthalic acid. The highest terephthalic acid (86%) recovery yield was reached at NaOH (0.3 g), GDS (0.02 g) and PET: waste molar mass ratios (1:3), respectively. In addition, obtained data showed that in the presences of GDS (0.02 g) required reaction time for complete glycolysis decreases up 98% and by exceeding the GDS to 0.05 g, the consumption of the solvent decreases to 62.5% in comparison with unsupported reaction.

Poly (ethylene terephthalate), Recycling, Terephthalic acid, Modified nanosilica (GDS)