Method for purifying polyether polyols made with double metal cyanide catalysts

摘要

A method for purifying polyether polyols made with double metal cyanide (DMC) catalysts is disclosed. A poly(oxypropylene) polyol containing DMC catalyst residues is combined with an amount of an alkali metal compound sufficient to convert DMC residues to an insoluble species, but not sufficient to generate polyol alkoxide groups. The polyol is heated in the presence of water, and is then filtered and stripped. The method eliminates the need to use magnesium silicate in removing DMC catalysts from polyols.