Effect of pigment and temperature onto swelling and water uptake during organic coating ageing

Water uptake values obtained from gravimetry and EIS, using the Brasher and Kingsbury equation, were different for all the temperatures for unpigmented and pigmented coatings. Using a modified Brasher and Kingsbury equation that considers the experimental swelling obtained by SECM, the same water uptake values were obtained for all systems and all temperatures. Finally, it appears that the coating swelling is a key parameter to evaluate water uptake in organic coatings, especially when different coatings are compared.