Synthesis, formulation, and characterization of siloxane-modified epoxy-based anticorrosive paints

Diglycidyl ether of bisphenol A epoxy (E) was modified with hydroxyl-termiriated polydimethylsiloxane through a ring-opening addition polymerization reaction. The structural elucidation of the siloxine-modified epoxy resin (ES) was carried out with Fourien transform infrared, H-1-NMR, and C-13-NMR spectroscopy techniques. The physicochemical characterization of the synthesized resin (ES) was performed with standard metho(;. E and ES were subjected to paint formulation with the help of a rutile (TiO2) pigment. The formulated paint systems were cured at room temperature with 1,6-cliaminohexame (AH) and 1,3-diaminopropane (AP), which were used as curatives. The E-AH, E-AP, ES-AH, and ES-AP paint systems were applied to mild steel strips. The physicomechanical and anticorrosive performance of the coated panels was evaluated with standard methods. The thermal analysis of these E-amine and ES-amine systems was carried out via thermogravimetric analysis. The effects of siloxane incorporation and amine curatives on the coating properties of the paint systems were also investigated. The ES-AP system exhibited good thermal and corrosion stability performance among all the E and ES paint systems. (c) 2006 Wiley Periodicals, Inc.