A Study on EVA Flame-Retarded with Intumescent Flame Retardants Containing Caged Bicyclic Phosphates

EVA was flame-retarded with IFR containing caged bicyclic phosphates--Trimer and PEPA. When the add-on IFR-P amount is about 30%, the flame-retarded EVA45 possesses an LOI of about 30% and a UL-94 V-0 grade. The heat release rate (HRR), total heat release (THR), mass loss rate (MLR) and the generation of smoke and toxic gases etc. of the flame-retarded EVA were measured. Compared with pure EVA, HRR, THR and MLR of the flame-retarded EVA are decreased by a factor of 50%～70%, 30%～40% and about 50%, respectively. In addition, a char layer can form during the combustion of flame-retarded EVA and the char layer shows a closed-cell structure with diameters of 5～30 μm and wall thickness of 6～9 μm. The laminated char with graphite-like structure forms during combustion.