High thermal stability and low flammability for Ethylene‐Vinyl acetate Monomer/Ethylene‐Propylene‐Diene Monomer by incorporating macromolecular charring agent

Abstract

The intumescent flame retardant (IFR) compounded with triazine charcoal‐forming agent (CFA) and ammonium polyphosphate (APP) was applied to the flame‐retardant modification of EVM/EPDM. The effect of APP‐CFA on the flame‐retardant performance of the composite was studied. The results showed that APP‐CFA effectively enhanced the flame‐retardant performance of EVM/EPDM. Compared with the control sample, when the APP–CFA ratio was 4:1, the limit oxygen index of EVM/EPDM with APP–CFA was up to 27.1%, which was increased by about 40%, and the average heat release rate was 110.1 kW/m2, which was reduced by about 29%. Moreover, it passed the UL‐94 V‐0 test. TGA results showed that after the addition of APP/CFA, the amount of residue significantly increased. SEM test showed that the char layer formed by the composite containing APP/CFA during combustion was denser and more uniform. In addition, compared with the traditional intumescent flame‐retardant ammonium polyphosphate–dipentaerythritol–melamine (APP‐DPER‐MN), the new flame‐retardant APP–CFA has better flame‐retardant and comprehensive performances.