摘要 |
Improved double metal cyanide catalysts are disclosed. The substantially amorphous catalysts of the invention are more active for polymerizing epoxides than conventional DMC catalysts, which have a substantial crystalline component. Polyol products made with the catalysts are unusually clear, have exceptionally low unsaturations, and contain no detectable amount of low molecular weight polyol impurities. Methods of making the improved DMC catalysts are also disclosed. In one method, the reactants are intimately combined to produce a catalyst of the invention. In another method, an organic complexing agent is initially present in the reactant solutions.
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