Anticorrosive properties of PDMS-Silica coatings: effect of methyl, phenyl and amino groups

[Display omitted] •DBTL is proposed as poly-condensation catalyst between TEOS and PDMS-modiffied.•TEOS/PDMS-modified form a homogenous coat on metallic surface.•Physical properties such as hardness and adhesion improve the corrosion resistance.•TEOS/PDMS-modified coatings improve the aluminum corrosion resistance from fair to excellent. Hybrid silica coating obtained from TEOS and PDMS using Methyl, Phenyl and Amino as functional groups of siloxane chain were obtained using Dibutyl-dilaurate tin (DBTL) as a neutral poly-condensation catalyst under free solvent conditions. The hybrid silica coating was characterized using different characterization techniques. FT-IR shows the presence of main functional groups for silica network and PDMS. On the other hand, TGA confirmed the formation of coatings with 76%w of ceramic yield. The C1s XPS peak analysis shows that only 30% of organic material corresponds to alkoxy groups without hydrolyzer from TEOS. Furthermore, Si2p peak XPS analysis shows that around 30% of ceramic network corresponds to Si-D and similar concentration to Q2 silicon species, which are found binding to siloxane chain from PDMS. Similarly, the Sn concentration on hybrid silica network was negligible according to Sn3d peak XPS. Furthermore, the corrosion resistance analysis for the different ceramic shows that the amino and phenyl groups improve the corrosion resistance for aluminum according to NACE international criteria.