Thermal enhancement of the purification process for interfacial polycarbonate and copolymer polycarbonates

摘要

In an embodiment, a process of purifying a polycarbonate comprises: polymerizing a dihydroxy compound and a carbonate source via an interfacial reaction in the presence of a catalyst to form a product mixture comprising an aqueous phase and an organic phase, wherein the organic phase comprises the polycarbonate, the catalyst, ions, and a solvent having a boiling point Tb; heating the product mixture to greater than or equal to Tb; separating the aqueous phase and the organic phase at a temperature greater than or equal to Tb to form a separated organic phase and a separated aqueous phase; extracting the catalyst from the separated organic phase; and extracting the ions from the separated organic phase; wherein if a centrifuge is used in the extracting of the catalyst, the extracting of the ions, or both, the process further comprises cooling a stream entering the centrifuge to less than Tb.

主权项

1. A process of purifying a polycarbonate comprising:
polymerizing a dihydroxy compound and a carbonate source via an interfacial reaction in the presence of a catalyst to form a product mixture comprising an aqueous phase and an organic phase, wherein the organic phase comprises the polycarbonate, the catalyst, ions, and a solvent having a boiling point Tb at atmospheric pressure; heating the product mixture to a temperature greater than or equal to the boiling point Tb to form a heated product mixture; separating the aqueous phase and the organic phase of the heated product mixture at a temperature greater than or equal to the boiling point Tb to form a separated organic phase and a separated aqueous phase; extracting the catalyst from the separated organic phase; and extracting the ions from the separated organic phase to form a purified polycarbonate; wherein if a centrifuge is used in the extracting of the catalyst, the extracting of the ions, or both, the process further comprises cooling a stream entering the centrifuge to a temperature less than the boiling point Tb.