| abstract |
A process for isolation of bisphenol A from depolymerization of a poly(carbonate) includes depolymerizing a poly(carbonate) having repeating units derived from bisphenol A in the presence of a base, a Ci-6 alcohol, and an organic cosolvent that is miscible with the Ci-6 alcohol and has a boiling point that is greater than 90°C, to provide a depolymerized reaction mixture including bisphenol A, a di(Ci-6 alkyl) carbonate, the Ci-6 alcohol, the organic cosolvent, and optionally, residual base; separating the di(Ci-6 alkyl) carbonate, the Ci-6 alcohol, and optionally, at least a portion of the organic co solvent from the depolymerized reaction mixture, to provide a di(Ci-6 alkyl) carbonate mixture; combining the di(Ci-6 alkyl) carbonate mixture with an aqueous base under conditions effective to hydrolyze the di(Ci-6 alkyl) carbonate to a corresponding Ci-6 alcohol; and crystallizing bisphenol A from the residual depolymerized reaction mixture to provide a purified bisphenol A. The bisphenol A isolated by the method described herein can have improved purity and can be particularly useful for providing thermoplastic polymers. |