Investigating the correlation between the curing behavior and properties of acrylic powder coatings

Abstract

Acrylic powder coatings are environmentally friendly, solvent-free solid coatings with excellent durability and corrosion resistance that protect substrates from corrosive environments. The curing behavior of acrylic powder coatings affects the coating film properties. In this study, a catalyst was used to control the curing conversion rate, and the curing characteristics and physical properties were compared for coatings with and without the catalyst. Differential scanning calorimetry and an isoconversional method were used to obtain activation energies, and the conversion rate under different isothermal conditions was computed. Notably, complete curing could not be achieved without the catalyst; however, the catalyst-containing coating was entirely cured. With sufficient curing established, the addition of the catalyst was found to increase the adhesion, impact resistance, and corrosion resistance. However, the recoatability was reduced owing to a lack of unreacted monomers on the surface of the catalyst-containing coating film, as verified by Fourier-transform infrared spectroscopy. In general, the addition of a catalyst to acrylic powder coatings enabled complete curing and enhanced most physical properties, offering an improved formulation for applications across high-corrosion environments.