Synergistic Effect of the Charring Agent on the Thermal and Flame Retardant Properties of Polyethylene

Abstract Summary: A new charring agent (CA), a derivative of triazines, was synthesized. The flame retardancy and thermal behavior of a new intumescent flame‐retardant (IFR) system for PE (PE‐IFR) were investigated by limited oxygen index (LOI), UL‐94 test, thermogravimetric analysis (TGA), and FTIR spectroscopy. The TG curves shows that the amount of residue of IFR‐PE system are largely increased compared to those of PE at temperatures ranging from 350 to 700 °C. The new PE‐IFR system can apparently reduce the amount of decomposing products at higher temperatures and promotes the formation of carbonaceous charred layers. It showed a distinct synergistic flame retardant effect (SE) between nitrogen and phosphorus. The flame retardant PE composition was optimized to achieve a LOI value of 31.2 and UL‐94 V‐0 performance with the synthesized charring agent, ammonium polyphosphate (APP). TG curves of PE, APP, CA, and different PE/CA/APP systems. magnified image TG curves of PE, APP, CA, and different PE/CA/APP systems.