Patent ID: 8709166

Claim:
A method for extracting a bisphenol from a polymer substrate comprising: contacting the polymer substrate with an aqueous composition comprising a phase transfer agent and a base, whereby the bisphenol is extracted in to the aqueous composition; wherein: the phase transfer agent is a quaternary organic ammonium compound of Formula I: R 1 , R 2 , R 3 , and R 4 may be the same or different and are independently selected from H, C 1 -C 20 alkyl, C 3 -C 8 cycloalkyl, heterocyclyl, C 6 -C 10 aryl and heteroaryl groups, or R 1 and R 2 or R 1 -R 3 together with the nitrogen atom to which they are bound are a part of heterocyclic ring system and at least one of R 1 , R 2 , R 3 , and R 4 is a C 6 -C 10 aryl or heteroaryl group; and X- represents an anion comprising halide, hydroxide, sulphonate, phosphate, alkylphosphate, dialkylphosphate, borate, alkylborate, nitrite, nitrate, carbonate, bicarbonate, alkanoate, or O,O-dialkyldithiophosphate.