Study on distributed resistivity and protective performance of silicone epoxy coatings with and without filler under tensile stress

The corresponding physical models of coating resistivity fitting were established according to the different failure processes and diffusion dynamics of SE and SET coatings under tensile stress. Power-law model was used to evaluate the protective performance of SE coating under tensile stress. Based on Young's theory, the two-layer model was established to evaluate the protective performance of SET coatings. Consequently, the resistivity distribution with coating thickness was calculated as a critical parameter to describe the protective performance of the coating. The water diffusion dynamics based on different coating structures were also provided for selecting the distribution model. •The failure process and diffusion dynamics of SE and SET coatings under tensile stress are different.•The resistivity distribution of the coating can be used as a critical parameter to characterise the protective performance of the coating under tensile stress.•Power-law model is used for resistivity distribution of SE coating with fillers under tensile stress.•The two-layer model and Young's model are respectively used in the early and middle/late immersion stages of SET coating under tensile stress.