Organic modified silica obtained from DBTL polycondensation catalyst for anticorrosive coating

DBTL as neutral polycondensation catalyst was employed to obtain organic modified silanes (ORMOSILs), which were studied as anticorrosive films for aluminum at saline corrosion. The ORMOSILs were synthesized using TEOS as silica precursor, different alkylalkoxysilanes (trimethoxy(methyl)silane, triethoxy(octyl)silane, 3-aminopropyl(triethoxy)silane and DBTL-catalyst were employed under the free solvent sol–gel process. Results of chemical characterization of ORMOSILs coatings show that under SEM technique coatings have homogenous films, and there are a crosslinking between silica and organic modified under the Infrared spectroscopy and 29 Si CPMAS-NMR techniques. On the other hand, Brinell hardness and Pull-Off adhesion tests show that all ORMOSILs increase the aluminum surface hardness between 1 and 10%, and the ORMOSILs critical forces for adhesion are in the range of 106–132 N; therefore, the ORMOSILs coatings have an excellent adhesion to aluminum surface, furthermore, the saline corrosion test shows that organic modified silica avoid the pitting aluminum corrosion; corrosion rate decreases about 60–85%; the anticorrosive behavior according to modified-silica was determined as: SiO 2 –NH 2 > SiO 2 –Me ∼ SiO 2 –Octyl. Highlights DBTL is proposed as poly-condensation catalyst between TEOS and alkylalkoxysilanes for the formation of anticorrosive coating. ORMOSIL increases the hardness of aluminum surface. DBTL forms ceramic hard coating with excellent adhesion. ORMOSIL–DBTL diminishes the corrosion rate at 60–85%.