Microwave‐assisted depolymerization of poly(ethylene terephthalate) [PET] at atmospheric pressure

Microwave‐assisted hydroglycolysis of poly(ethylene terephthalate) using an excess of methanol, ethanol, 1‐butanol, 1‐pentanol, and 1‐hexanol in the presence of different simple basic catalysts, namely, potassium hydroxide, sodium hydroxide, sodium acetate, and zinc acetate, is reported. Reactions were performed at short times without any side reactions, namely, oxidation of ethylene glycol. The products terephthalic acid and ethylene glycol were obtained in their pure form with sufficiently high yields with potassium hydroxide. The purified product was characterized by IR and nuclear magnetic resonance spectroscopy. The process of hydroglycolysis reported here is economically viable since yields of recycled products are high, and it has potential for further improvement to produce useful products. This process is of economic interest because much of the raw materials can be recovered and used for virgin PET resin synthesis.