Structure and properties of polyether polyols catalyzed by Fe/Zn double metal cyanide complex catalyst

A new kind of double metal cyanide (DMC) complex catalyst based on Zn3[Fe(CN)6]2 was synthesized and developed by reaction between aqueous solutions of zinc chloride and potassium hexacyanoferrate with complexing agents to form a precipitate of the DMC compound. For obtaining favorable catalyst activity, the organic complexing agents such as t-butanol and polyols are employed. The complexing agents are incorporated into the catalyst structure, and are required for active catalysts. Several kinds of polyether polyols are prepared by the Fe–Zn DMC catalyst. The structure and properties of polyether polyols are characterized by GPC, FT-IR, and 13C NMR. The results show that the polyether polyols catalyzed by these Fe–Zn DMC catalysts are of low unsaturation, high molecular weight, narrow molecular distribution compared with the polyether polyols catalyzed by traditional KOH catalysts. High resolution 13C NMR analytical results show that head–tail addition and random stereoirregular structure is dominant in polyether polyols microstructures which are catalyzed by these DMC catalysts.