Electrochemical behavior of carbon steel pre-treated with an organo functional bis-silane filled with copper phthalocyanine

the bis-[trimethoxysilylpropyl]amine (btspa) film filled with copper phthalocyanine (cu-ph) was prepared by adding different concentrations of copper phthalocyanine - cu-ph and deposited on a carbon steel substrate using 120 oc and 150 oc as curing temperatures. for samples cured at 150 oc a second layer was also deposited. the electrochemical behavior of carbon steel coated with btspa filled with cu-ph was studied by electrochemical measurements, electrochemical impedance spectroscopy (eis) and polarization curves, in aerated 0.1 mol l-1 nacl solution. physical and chemical characterization was made by thermogravimetric analysis (tga), scanning electron microscopy, contact angle measurements and infrared spectroscopy. tga showed no decomposition of cu-ph during the curing process. cu-ph added into the silane film showed a strong influence on its corrosion resistance, mainly when the samples are cured at 150 oc. the results showed that lower inhibitor concentrations led to a higher corrosion resistance and the second layer increased by one order of magnitude the corrosion resistance.