On the Influence of Metal Alkoxides on the Epoxide Ring-Opening and Condensation Reactions of 3-Glycidoxypropyltrimethoxysilane

摘要: The extent of the epoxide ring-opening, formation ethyl ether groups as one reaction product ring-opening and condensation degree RSi(O0.5)3 units in sols gels system 3-glycidoxypropyltrimethoxysilane (GPTS)-1.5H2O-0.01/0.1/1.0 metal alkoxide [Si(OEt)4, Sn(OBut)4, Al(OBus)3, Al(OEtOBu)3, Ta(OEt)5, Ti(OEt)4, Zr(OBun)4] ethanol has been examined by means liquid- solid-state 13C 29Si NMR spectroscopies. results reveal a strong effect Al-alkoxides hybrid after 24 h time Zr-, Ta-, Al- Sn-alkoxides corresponding already at low concentration (1 mole%). rate increases with higher (10 mole%) but decreases 50 mole% Al-, Ti- Zr-alkoxides. activity alkoxides 10 order Si(OEt)4 < Ti(OEt)4 Zr(OBun)4 Al(OEtOBu)3. contain considerable amounts (up to 90%) which lowers polyether bonds. (c.d.) GPTS-1.5H2O up 80% 7 order: ≪ Sn(OBut)4 Al(OBus)3 Al(OEtOBu)3 Ta(OEt)5 Ti(OEt)4. An additional increase c.d. 90% follows thermal sol-gel transformation. Generally, maximum reactions was found additives. water on is discussed. Furthermore, compared nanoscaled oxides.