A method for preparing a polycarbonate

Abstract

The present application relates to the technical field of catalytic melt transesterification, and particularly relates to a preparation method of polycarbonate. The present application provides a preparation method of polycarbonate, comprising the following steps: under the action of a catalyst, carrying out melt transesterification reaction and polycondensation reaction on diphenyl carbonate and bisphenol A in sequence to obtain polycarbonate; the catalyst is an azole alkali metal salt; the number average molecular weight of the polycarbonate is greater than 20,000, the weight average molecular weight is greater than 30,000, and the PDI is less than 2.3; the temperature of the melt transesterification reaction is 140-160 DEG C, and the time is greater than or equal to 40 min; the temperature of the polycondensation reaction is 200-250 DEG C, and the time is 1.5-3 h. The polycarbonate prepared by the preparation method using an azole alkali metal salt as the catalyst has a narrow molecular weight distribution and high thermal stability.

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