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 model the interaction between drying oils and sol−gel precursors in inorganic/organic coatings. The metal carboxylates were prepared by reacting titanium isopropoxide [Ti(O- i -Pr) 4 ] with linolenic and oleic acids. Nuclear magnetic resonance spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and Fourier transform Raman (FT-Raman) spectroscopy were used to investigate the bond formation between Ti(O- i -Pr) 4 and free fatty acids. The 13 C NMR and FT-IR spectra indicate the metal carboxylates are complex mixtures of bidentate chelating, bridging, and metal−oxo bridging clusters. The incorporation of unsaturated metal carboxylates in linseed oil coatings increased the glass transition temperature to 49 °C and increased the cross-link density to 1.41 × 10 - 3 mol/cm 3 .