Model reaction study on the interaction between the inorganic and organic phases in drying oil based ceramer coatings

Metal-oxo carboxylates containing unsaturated fatty acids were used to mode l the interaction between drying oils and sol-gel precursors in inorganic/o rganic coatings. The metal carboxylates were prepared by reacting titanium isopropoxide [Ti(O-i-Pr)(4)] With linolenic and oleic acids. Nuclear magnet ic resonance spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and Fourier transform Raman (FT-Raman) spectroscopy were used to investiga te the bond formation between Ti(O-i-Pr)(4) and free fatty acids. The C-13 NMR and FT-IR spectra indicate the metal carboxylates are complex mixtures of bidentate chelating, bridging, and metal-oxo bridging clusters. The inco rporation of unsaturated metal carboxylates in linseed oil coatings increas ed the glass transition temperature to 49 degreesC and increased the cross- link density to 1.41 X 10(-3) mol/cm(3).