Bio-based coating resins derived from cardanol using carbocationic polymerization and their evaluation as one-component alkyd-type coatings

A novel biobased monomer, cardanol ethyl vinyl ether (CEVE) and its autooxidatively curable linear homopolymer and copolymers were synthesized using carbocationic polymerization. Cardanol, a component of cashew nut-shell liquid has a unique phenolic structure with an unsaturated fatty chain. The polymers were cured oxidatively at both ambient and elevated temperatures (120 and 150 °C) resulting in crosslinked networks with better physical and thermomechanical properties than two commercial reference alkyds. Variations in the glass transition temperature (Tg) (5.6 to 26 °C), crosslink density (3.92 to 16.6 mol/cm3), tensile properties (12.2 to 26.6 MPa), and hardness (15 to 40 Sec.) were achieved by changing the copolymer composition from poly(CEVE) to poly(CEVE-co-CHVE)-50/50. These results clearly show the potential of these cardanol-based polymers for use as surface coatings.