Reaktion #59225

Reaktionsgleichung

4,4′-dihydroxydiphenyl ether

phosgene

sodium hydroxide

p-tert.-butylphenol

sodium hydroxide

n-ethylpiperidine

bisphenol A

→

bisphenol A 4,4′-dihydroxydiphenyl ether

Lösungsmittel

methylene chloride

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added during the phosgenation
2. 2
   workup.ADDITIONis added as catalyst
3. 3
   SonstigeThe aqueous phase is separated off
4. 4
   Waschenwashed with distilled water until neutral and free of salt
5. 5
   SonstigePrecipitation of the polymer in methanol
6. 6
   Trocknendrying yield 17.29 g of polycarbonate

Vorschrift

131 ml of methylene chloride are added to a solution, rendered inert with nitrogen, of 1.618 g (0.008 mol.) of 4,4′-dihydroxydiphenyl ether and 16.438 g (0.072 mol.) of bisphenol A as well as 7.04 g (0.176 mol.) of sodium hydroxide in 131 ml of water. In a one-step procedure, 0.36 g (0.0024 mol. or 3.0 mol. % relative to bisphenol) of p-tert.-butylphenol (BUP) are added as chain terminator. At a pH value of 14 and at room temperature, 11 ml (15.8 g, 0.16 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, 0.11 ml (0.0008 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 17.29 g of polycarbonate.

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