Alkaline hydrolysis of poly(ethylene terephthalate) in presence of a phase transfer catalyst

Poly(ethylene terephthalate) (PET) powder was hydrolyzed at atmospheric pressure in 5-10 wt% aqueous NaOH at 95°C for 100 min using some phase transfer catalysts (PTC) with an intention to recover the starting monomers from the waste PET. The intent behind attempting new PTC was to carry out the reaction at milder conditions than those reported in the literature. One of the monomers, terephthalic acid (TPA) was produced in the presence of a PTC during the alkaline hydrolysis of PET. The TPA yield agreed with the degree of hydrolysis of PET. Benzalkonium chloride (BKC) was found to be the most effective catalyst among the ones studied. Operating parameters such as NaOH concentration, catalyst concentration and reaction temperature were optimized.