Enhancing the anti-corrosion performance of water-borne acrylic coatings
During the study, acrylic-alkyd copolymers with varied contents of the alkyd copolymer have been synthesised by free radical polymerisation in order to create water-borne coatings with distinct molecular structures to enhance anti-corrosion performance.
The acrylic-alkyd copolymers were found not only to possess combined advantages of acrylic and alkyd resins in coating properties such as stability, fast drying and hardness, but also to possess several properties required for enhanced corrosion resistance, especially a higher hydrophobicity of the coating surface, a lower water diffusion coefficient, and a denser network of copolymer films.
Significant enhancement in the corrosion resistance
The higher hydrophobicity of the coating surface was achieved through the design of acrylic-alkyd copolymers with acrylic branches and hydrophobic alkyd backbones, leading to increase in the water contact angles of the copolymer films. The denser coating network was achieved by the branched structure and the flexibility of the copolymer chains. This allows the copolymer particle stacking during the curing process and builds a denser barrier film with lower water diffusion coefficients.
These coating properties have led to significant enhancement in the corrosion resistance of these acrylic-alkyd copolymer films, which has been confirmed by the results from electrochemical impedance spectra (EIS) and corrosion exposure tests.
The study has been published in Progress in Organic Coatings, Volume 154, May 2021.