ATH/ADP配比对EVA阻燃性能及机理转变的影响OA北大核心CSTPCD

To improve the flame-retardant properties of ethylene-vinyl ecetate copolymer(EVA)with aluminum hydroxide(ATH),a blend of aluminum diethylphosphite(ADP)and ATH was used.The flame-retardant properties of the composites were evaluated by using vertical burning(UL-94),limiting oxygen index(LOI),and cone calorimeter(CONE)tests.The results indicated that at the mass ratio of ATH to ADP of 2∶1 and 1∶2,compared to the EVA/ATH composites,the vertical burning rating improved from no rating to Ⅴ-0,and the LOI increased from 34.5％to 37.8％and 42.8％,respectively.Different methods were used to analyze the flame-retardant mechanisms of samples with these two ratios.For the sample with a mass ratio of ATH to ADP of 2∶1,the content of phosphorus-containing compounds released during thermal decomposition was extremely low,and the formation of aluminum phosphate(AlPO4)strengthened the char layer,made it more continuous and dense,resulting in higher residue mass than theoretical value.Therefore,the proposed flame-retardant mechanism at this ratio is dominated by the condensed phase.For the sample with a mass ratio of ATH to ADP of 1∶2,the char layer had more pores,and the residue mass was lower than theoretical value,but high content phosphorus-containing compounds appeared in the gaseous products.Hence,the proposed flame-retardant mechanism at this ratio is dominated by gas phase.