Research shows that two renewable PIN flame retardants can be combined: Phosphorus based phytic acid (widely present in plant seeds) and Nitrogen containing chitosan (derived from natural chitin, present in the structures of fungi, crustaceans …). The two renewable compounds were combined to produce a polyelectrolyte complex (PEC), which was then reacted onto EVA (ethylene-vinyl acetate) fibres.
EVA is widely used in many applications, including wires and cables where fire safety and low smoke are required. A reduced peak heat release and total heat release were achieved, with a full and compact char layer, without deterioration of the fibres properties (ductility, tensile strength, viscoelacticity).
“Chitosan/Phytic Acid Polyelectrolyte Complex: A Green and Renewable Intumescent Flame Retardant System for Ethylene-Vinyl Acetate Copolymer”, T. Zhang et al., Ind. Eng. Chem. Res. 2014 http://pubs.acs.org/doi/abs/10.1021/ie503421f