Siloxanes from the hydrolysis of isopropyltrimethoxysilane
摘要:
The behavior of isopropyltrimethoxysilane (1) in the presence one equivalent of water and a dibutyltin dilaurate catalyst has been investigated. Under these conditions, partial hydrolysis of the methoxy groups of 1 occurred, followed by condensation reactions leading to the formation of low molecular-weight oligomers. Disiloxane 4, trisiloxane 6 and cyclic siloxanes 7 and 8 have been isolated and fully characterized. Transient reaction intermediates silanol 3 and hydroxydisiloxane 5 have been characterized spectroscopically, The time evolution of these species was followed by gas chromatography and Si-29 NMR. A reaction scheme for the hydrolytic condensation of 1 is proposed to accommodate these results.