Research progress in cardanol-based flame retardant polymer materials

With the increasing awareness of environmental protection and the proposal of the national carbon peak strategy， the use of renewable bio-based resources for the preparation of flame retardant polymer materials has received widespread attention. Cardanol is an abundant and cost-effective biomass with multiple highly reactive functional groups， which is expected to be used for the preparation of commercial flame retardant polymeric materials. The preparations of cardanol-based flame retardant additives for modifying polyvinyl chloride， unsaturated polyester thermosets， and epoxy thermosets were summarized. Their performances were comparatively analyzed. The recent research progress in flame retardant cardanol-based epoxy thermosets， flame retardant cardanol-based benzoxazines， flame retardant cardanol-based ultraviolet-curable coatings， flame retardant cardanol-based polyurethane foams， and flame retardant cardanol-based phenolic foams were summarized. It is pointed out that the preparation of multifunctional flame retardant cardanol-based polymer materials with excellent comprehensive performance is the key direction of future research.