Synergistic Effects of Cardanol- and High Oleic Soybean Oil Vinyl Monomers in Miniemulsion Polymers

Along with characterization of vinyl monomers from high oleic soybean oil (HOSBM) and cardanol (CBM) in free radical (co)­polymerization, a series of stable latexes based on various ratios of these fully renewable plant-based monomer mixtures have been synthesized using a miniemulsion process. The combination of aliphatic fatty acid fragments of HOSBM with aromatic CBM structure led to the formation of durable latexes from fully renewable feeds as well as the ability of the resulting cross-linked latex films to balance thermomechanical properties. Biobased latexes were synthesized from 10 to 75 wt % of CBM and 25–90 wt % of HOSBM in the feed, characterized, and tested in films and coatings performances. The synergistic effects of both the constituents in the films and coatings were observed. The incorporation of cardanol-based fragments enhances the Young’s modulus of the films, whereas the plant oil-based units contribute to softer and more flexible films. Even small (10 wt %) fractions of CBM can provide noticeable strength to the soft latex polymer material based entirely on HOSBM. All cross-linked latex films in this study exhibit decent properties and performance in terms of pendulum and pencil hardness, water and solvent resistance, as well as adhesion to the steel substrate. To the best of our knowledge, latexes from fully renewable plant-based monomer mixtures have not been reported before in literature