Phosphorus modified cardanol: a greener route to reduce volatile organic compounds and bring flame retardant properties to alkyd resins coatings

Abstract : Alkyd resins occupy a prominent place among the coating industry [1]. However, they have two major drawbacks, the presence of solvents as volatile organic compounds and their high flammability[2,3,4]. The present work investigates a two-in-one solution by setting up novel phosphonate and phosphate cardanol-based reactive diluents with flame retardant properties for alkyd resins. The alkyd resins were applied as coatings on wood surface and their fire behaviors were investigated. All the results have exhibited an improvement of FR properties with the increase of phosphorus content, demonstrating an action in condensed phase by promoting char formation for phosphonate and phosphate compounds. The most promising results were obtained with 2 wt% of phosphate in the alkyd resin formulation and exhibited a 41 % reduction in pHRR compared to the resins without phosphorus-containing cardanol diluent.