A comparative study on water resistance of polyurethane and epoxy resin coatings
In this study,the hydrolysis behavior of four types of polymer coatings,including three polyurethanes and one epoxy resin were evaluated with the assistance of Fourier-transform infrared spectroscopy,solid-state nuclear magnetic resonance,thermogravimetric analysis,and dynamic mechanical analysis.The results demonstrated that the polyether-based polyurethane coating exhibited superior water resistance and minimal impact on its chemical structure due to hydro-lysis.However,the incorporation of ceramic particles can significantly accelerate the hydrolysis,resulting in an increase in water absorption and a decrease in coating performance.Both polyester-based polyurethane and epoxy resin coatings exhibited poor water resistance under the same conditions,and a chemical degradation might occur,resulting in an in-crease in storage modulus.