Research on Seawater Corrosion Resistance of Spray Polyurea Protective Coating

Abstract

In this paper, the changes of mechanical properties and surface properties of QF-162 polyurea coating after soaking in seawater for 120 days were studied. The changes of internal chemical bonds before and after coating corrosion were observed with Fourier Transform infrared spectroscopy (FT-IR). The results of mechanical properties study showed that after soaking in seawater for 120 days, the tensile strength of QF-162 polyurea coating decreased by 4.23%, the elongation at break decreased by 7.10%. The hardness changed slightly and Shore A hardness decreased by 3.23%. Surface performance results showed that the contact angle of QF-162 polyurea coating decreased with the increase of soaking time, and the surface energy showed a trend of increase. After soaking 120 days, the contact angle of polyurea coating decreased by 6.08%, surface energy increased by 15.83%. FT-IR microscopic results showed that there was no obvious fracture phenomenon in the internal chemical bonds of QF-162 polyurea coating and the coating had good anti-corrosion to seawater soaking.