Catalytic Effect of Chemically Modified Metal Alkoxides on Hydrolysis and Condensation Reaxctions of Methyl-and Phenyl-Ethoxysilanes

摘要

The catalytic effect of chemically modified metal alkoxides on the hydrolysis and condensation reactions of methylethoxysilanes and phenylethoxysilanes was investigated bvy ~29Si nuclear magnetic resonance spectroscopy and gel permeation chromatography.Metal alkoxides such as Al(O-sec-C_4H9)_3,Ti(O-iso-C_3H_7)_4 and Nb(OC_2H_5)_5 modified with ethyl acetoacetate accelratednot only the condensation reactions but also the hydrolysis reactions of methyl-and phenyl-alkoxysilanes.The catalytic effect of these metal alkoxides was found to be different between methyjjl-and phenyl-alkoxysilanes.The catalytic activity increases in the order of Nb