Abstract: Ester bonds are hydrolyzed in the conversion of substantially amorphous polyesters to their monomeric components, by being contacted with a mixture of (a) an alcohol, such as methanol, or glycol, (b) a polar aprotic solvent such as N-methyl-pyrrolidone or dimethyl sulfoxide and (c) an alkoxide or hydroxide such as sodium hydroxide.

Abstract: A method for removing impurities from an oxidative terephthalic acid synthesis mother liquor containing acetic acid, water, corrosion metals, a metal catalyst and organic impurities, comprising the steps of (a) removing from the mother liquor by evaporation from 50-95% of the acetic acid and water contained therein; (b) adding an amount of water to the concentrated mother liquor sufficient to dissolve the metal catalyst and form an aqueous mixture; (c) extracting the aqueous mixture by counter-current extraction with a substantially water-insoluble organic solvent, to produce a lighter phase containing the organic solvent, a minor amount of the water, acetic acid and the organic impurities and a heavier phase containing a major amount of the water, corrosion metals and the metal catalyst, and; (d) removing the corrosion metals from the heavier phase by heating and filtering, and; (e) removing the organic impurities from the lighter phase by distillation.