AASHTO T 339-10 (2019) PDF Download

AASHTO T 339-10 (2019) is a standard method of test that provides guidelines for the analysis of structural steel coatings to determine the isocyanate content. Isocyanates are important components of the resin system found in polyurethane paints, which are widely used for their protective properties in structural steel applications.

The standard outlines the procedure for testing the isocyanate content in the resin system. It specifies the necessary equipment and materials, such as solvents, titration apparatus, and a suitable analytical balance. The test involves dissolving the coating sample in a solvent, followed by the addition of a titrant solution to react with the isocyanate groups. The excess titrant is then back-titrated to determine the amount of unreacted isocyanate.

This method of analysis is crucial for evaluating the quality and performance of structural steel coatings. The isocyanate content provides an indication of the cross-linking density of the polyurethane resin and has an impact on properties such as adhesion, hardness, and chemical resistance. By testing the isocyanate content, the standard helps ensure that the coating meets the desired specifications and provides effective corrosion protection for the steel structure.