| abstract |
Cyclic polycarbonate oligomers are prepared by a method which is adaptable to continuous operation, by the reaction of a bisphenol bischloroformate (e.g., bisphenol A bischloroformate) with an amine (e.g., triethylamine) and an alkali metal hydroxide in a tank reactor (preferably a continuous stirred tank reactor) in a mixed aqueous-organic system, with agitation (preferably by stirring) at a rate just sufficient to prevent segregation of the aqueous and organic liquid phases. The residence time of the mixture in the reactor is preferably about 8-12 minutes. |