Conventional coating films are typically solvent based and contain a high percentage of volatile organic compounds (VOCs), which are environmentally damaging and pose health risks to humans. Our developments have been made to the introduction of water-bone low VOC coating systems. Research into the bulk material properties of these low VOC coatings is necessary to understand the degradation process of the coatings. Water sorption behavior of the bulk was focused in this research. We attempt to determine the kinetic of water sorption properties of water-bone urethane/epoxy coating and its effect on mechanical strength.
As results, we found that a high water affinity of water-bone coating supports higher saturated water content, and helps to facilitate absorption while hindering desorption. Increasing water content was shown to strongly correlate with a decrease in the Eo and ß during absorption between Mt/M8 = 0 and Mt/M8 ˜0.5. And, the adhesive characteristics of the coatings are correlated to water content, and shown to exhibit higher cohesive failure in the coating epoxies under saturated conditions which suggests water interferes with intermolecular bonding and reducing the bulk materials ability to diffuse stress concentrations and lowering its overall strength.