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 Zn-3[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 C-13 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 C-13 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. (C) 2003 Elsevier B.V. All rights reserved.