Synergy effect of silane and CTAB on corrosion-resistant property of low infrared emissivity Cu/polyurethane coating formed on tinplate

Synergy effect of the surface modification of copper (Cu) by surfactant, cetyl trimethyl ammonium bromide (CTAB) and coupling agent, gamma-aminopropyltriethoxy silane (KH550), on the corrosion-resistant property of low infrared emissivity Cu/polyurethane (PU) coating formed on tinplate was evaluated. Infrared spectra revealed an obvious interaction between Cu and PU induced by the addition of KH550, which implied that KH550 can improve the chemical interfacial interaction while CATB only improved the physical interaction between Cu and PU. The corrosion behavior of Cu/PU coating has been investigated with potentiodynamic polarization. Results have shown that the interfacial interaction between Cu and PU was improved by the synergy effect of proper amount of KH550 and CTAB, benefiting to the dispersion of Cu and the low porosity of Cu/PU coating, which keeps the low infrared emissivity and increases the corrosion resistance of the Cu/PU coating formed on tinplate.