Method for preparation of block copolysiloxanecarbonates

摘要

Copolysiloxanecarbonates are prepared in the melt by the reaction of a diaryl carbonate such as diphenyl carbonate with a mixture of a dihydroxyaromatic compound and a carbonate-terminated polydiorganosiloxane, the latter typically prepared by reaction of a diaryl carbonate or aryl chloroformate with a hydroxyorgano-terminated polydiorganosiloxane. By this method, incorporation of silicone units in the copolysiloxanecarbonate is maximized.