Phosgene → bisphenol TMC 4,4'-dihydroxydiphenyl ether

Beteiligte Stoffe

Reaktionsschritte

130 ml of methylene chloride are added to a solution, rendered inert with nitrogen, of 7.077 g (0.035 mol.) of 4,4′-dihydroxydiphenyl ether and 10.87 g (0.035 mol.) of bisphenol TMC as well as 6.16 g (0.154 mol.) of sodium hydroxide in 130 ml of water. In a one-step procedure, 0.368 g (0.0024 mol. or 3.5 mol. % relative to bisphenol) of p-tert.-butylphenol (BUP) are added as chain terminator. At a pH value of 14 and at room temperature, 9.7 ml (13.8 g, 0.14 mol.) of phosgene are added in the course of 10 minutes. In order to prevent the pH value from falling below 12, 25% sodium hydroxide solution was added during the phosgenation. When the phosgenation is complete, and after rinsing with nitrogen, 0.10 ml (0.0007 mol., 1 mol. % relative to bisphenol) of n-ethylpiperidine is added as catalyst, and stirring is then carried out for one hour. The aqueous phase is separated off, and the organic phase is acidified with phosphoric acid and washed with distilled water until neutral and free of salt. Precipitation of the polymer in methanol and drying yield 14.08 g of polycarbonate.

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