4A zeolite synergistic agent in new flame retardant intumescent formulations of polyethylenic polymers - Study of the effect of the constituent monomers

4A type zeolite adducted in the intumescent ammonium polyphosphate (APP)/pentaerythritol (PER) system, additives in fire retardant (FR) polyethylenic-based formulations (ethylenic co/terpolymers), leads to a synergistic FR effect. This study concerns ethylenic co- or terpolymers. It shows the part played by the polymeric matrix on the fire-proofing performances which depend on the chemical nature and amount of comonomer in the polymer. Further, the thermal analyses confirm the effect of the polymeric matrix and show the participation of oxygen in the formation of the intumescent coating. Measurement of the performances using the cone calorimeter puts forward that the zeolite causes different degradation of the intumescent materials and thus the formation in fire of a more thermally stable coating. (C) 1996 Elsevier Science Limited