Dynamics and corrosion resistance of amine-cured organically modified silicate coatings on aluminum alloys

Hybrid coatings based on amine-cured organically modified silicate were synthesized through a sol–gel technique. 3-glycidoxypropyltrimethoxysilane tetraethylenepentamine, and tetraethoxysilane were used as precursors for the hybrid coatings. These Ormosil films were deposited via spin coating onto an aluminum alloy to improve the corrosion protection. The effects induced by the curing agent content of tetraethylenepentamine (TEPA) on the chain dynamics and corrosion performance of the coated samples were investigated. The Si–H polarization transfer relaxation times and the rotating-frame spin-lattice relaxation times indicated that the configuration of the Ormosil films was highly crosslinked and dense and adhered to the aluminum alloy substrates. Potentiodynamic evaluation revealed that the Ormosil films provided exceptional barrier and corrosion protection in comparison with untreated AA substrates.