Multiple Thermal Immersion Ageing of Commercial Epoxy Coatings

Purpose – The purpose of this paper is to evaluate the degradation of two commercial epoxy coatings with different pigments recommended for marine immersion, in a proposed short time accelerated aging cycle, correlating the electrochemical, thermal and superficial characterization.Design/methodology/approach – An immersion accelerated ageing method in an aggressive environment with increasing temperature has been described: samples of two films applied on AISI 1010 steel and films free of substrate of two different pigment coatings were submerged in hot brine, maintaining them for 24 h at 25°C, then increasing daily in 20°C increments to 85°C; followed by cooling to 25°C. The applied samples were evaluated in situ electrochemically using electrochmical impedance spectroscopy (EIS) (while they were in the heated environment) and the free films were submitted to differential scanning calorimetry (DSC) and scanning electronic microscopy (SEM) at the beginning and end of each temperature stage.Findings – Resu...