Michael addition curable coatings from renewable resources with enhanced adhesion performance

Novel malonate-functional polyesters from biobased and potentially biobased monomers were developed and cured through the base-catalyzed carbon-Michael addition reaction with acryloyl-functional oligomers. Both drop-in monomers, such as fully biobased diethyl malonate, and alternative raw materials, such as isosorbide and vegetable oil, were introduced. Isosorbide-based polyesters show improved performance to humidity in terms of adhesion on epoxy-amine primer, while vegetable oil-containing resins lead to improved coating appearance due to better flow and levelling. This study demonstrates that biobased malonate resins, having renewable contents up to 53%, offer attractive performance benefits in 2K RMA paints. It is anticipated that, with the development of additional fully biobased polyols, renewable contents in excess of 80% can be achieved.