A new study presents bio-based coating resins derived from cardanol using carbocationic polymerisation 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 synthesised using carbocationic polymerisation. 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.
Great potential
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. According to the researchers, these results clearly show the potential of these cardanol-based polymers for use as surface coatings.
The study has been published in Progress in Organic Coatings, Volume 174, January 2023.