Chwan-hwa Chiang, N. Liu, J. Koenig
Mar 1, 1982
Citations
1
Influential Citations
126
Citations
Quality indicators
Journal
Journal of Colloid and Interface Science
Abstract
Abstract The high-resolution solid-state carbon 13 nuclear magnetic resonance spectra of γ-aminopropyltriethoxysilane (APS) and N-2-aminoethyl-3-aminopropyltrimethoxysilane (AAPS) condensed as bulk polymers and adsorbed on glass surfaces have been investigated. It is shown that the 13 C NMR resonance peaks of the low-cured and high-cured polyaminopropylsiloxanes are chemically shifted from one to another. The hydrogen-bonded APS propyl chain produces an upfield shoulder on the central methylene carbon resonance peak in a cross polarization with magic-angle sample-spinning (CPMASS) experiment. Measurements of the chemical shifts of non-heat-treated and heat-treated APS/glass samples were also made and the chemical shift trends are discussed in terms of oriented and extended conformational effects of propyl units. Three molecular structure models of APS are proposed involving a hydrogen bonding interaction by the amine and SiOH groups. The chemical shifts induced by electric field effects on the β-carbon nucleus for different APS isomers have been calculated and the results agree with the observed resonances.