	US 12,312,306 B2
	Degradation of plastic materials into terephthalic acid (TPA), ethylene glycol and/or other monomers that form the plastic materials
Samantha Lynn Anderson, Pully (CH); Christopher Patrick Ireland, Pont-de-la-Morge (CH); Berend Smit, St-Sulpice (CH); and Kyriakos Stylianou, Sion (CH)
Assigned to ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL), Lausanne (CH)
Appl. No. 17/433,137
Filed by ECOLE POLYTECHNIQUE FEDERALE DE LAUSANNE (EPFL), Lausanne (CH)
PCT Filed Feb. 25, 2020, PCT No. PCT/EP2020/054942 § 371(c)(1), (2) Date Aug. 23, 2021, PCT Pub. No. WO2020/173961, PCT Pub. Date Sep. 3, 2020.
Claims priority of application No. 19159827 (EP), filed on Feb. 27, 2019.
Prior Publication US 2022/0153674 A1, May 19, 2022
Int. Cl. C07C 29/09 (2006.01); C07C 51/09 (2006.01); C08J 11/14 (2006.01)

CPC C07C 51/09 (2013.01) [C07C 29/095 (2013.01); C08J 11/14 (2013.01); C08J 2367/02 (2013.01)]

9 Claims

1. A method of alkaline hydrolysis of a polyester into monomers that form the polyester, the monomers comprising terephthalic acid, the method comprising:

a) contacting the polyester with TiO₂particles in a solution in the presence of NaOH to provide a reaction mixture, the TiO₂particles being added to the solution separately from the polyester, the solution comprising a solvent consisting of (i) alcohol or (ii) a mixture of alcohol and <50 volume % water, the alcohol is selected from the group consisting of methanol, ethanol, propanol, butanol, pentanol, and a combination thereof, a weight ratio of the polyester to the NaOH (polyester:NaOH) is 1:10 to 1:1, and a weight ratio of the polyester to the TiO₂(polyester:TiO₂) is 1:0.0375 to 1:0.00125;

b) stirring the reaction mixture under UV light at room temperature and normal atmospheric pressure for greater than or equal to 6 hours and less than or equal to 9 hours to hydrolyze the polyester into the terephthalic acid, wherein the UV light comprises UVA light having a wavelength in a range of from 315 nanometers to 400 nanometers; and

c) recovering the terephthalic acid from the reaction mixture, wherein the terephthalic acid recovered from the reaction mixture comprises greater than or equal to 90% of the terephthalic acid from the polyester calculated based on the average molecular weight of repeating units in the polyester.