Effect of γ-irradiation on flame retardant ethylene-octene copolymers composites

A flammability study was made for the flame retardant composites EMA(POE/Mg(OH)2/Al(OH)3) and EMAP(POE/Mg(OH)2/Al(OH)3/P) before and after irradiation. Limiting oxygen index (LOI), mechanical property, morphology of the char formed after combustion and thermal stability were investigated. By γ-irradiation, the LOI of EMAP increased markedly, but the LOI of EMA remained almost the same. And in the same absorbed dose, the LOI of EMAP was greater than EMA. The char structure of irradiated EMAP was more compact than before irradiation. The residue char of EMAP and EMA increased after irradiation. (authors)