Jiao CM, Chen XL (2009) Synergistic Flame Retardant Effect of Lanthanum Oxide in Ethylene-vinyl acetate/Aluminium Hydroxide Composites. Iranian Polymer Journal 18(9), 723-730. [In English]

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Keywords:

lanthanum oxide, aluminium hydroxide, synergistic effect, flame, retardant, ethylene-vinyl acetate, silicate nanocomposites, aluminum-hydroxide, acetate copolymer, mechanical-properties, thermal-degradation, cone calorimeter, combustion, system, rubber, eva

Abstract: The flammability characterization and synergistic flame retardant mechanism of lanthanum oxide (La(2)O(3)) in the ethylene-vinyl acetate/aluminium hydroxide (EVA/ATH) composites were studied by limiting oxygen index (LOI), UL 94 test, cone calorimeter test (CCT), and thermogravimetric analysis (TGA). The results showed that the addition of a given amount of La(2)O(3) apparently increased the LOI value, which for the sample with 1.5 wt% La(2)O(3) reached 37.5. However, the addition of La(2)O(3) cannot enhance the ratings of UL 94 test. The data obtained from the CCT indicated that the addition of La(2)O(3) greatly prolonged the time to ignition, increased the fire performance index (M), and predictably reduced the fire growth index (FGI). It has been found that there is a synergistic flame retardant effect between La(2)O(3) and ATH in EVA/ATH/La(2)O(3) composites. The synergistic mechanism between La(2)O(3) and ATH is due to its physical process in the condensed phase, as revealed by CCT data showing that the addition of La(2)O(3) can make the formation of a more thermally stable barrier, and the residual char of the system with La(2)O(3) is higher than that of the system without La(2)O(3). A compact barrier produced by La(2)O(3) collaborating with ATH consequently leads to the decrease of heat release rate, mass, and total release rate as detected by CCT TGA results showed that La(2)O(3) can enhance the thermal stability of the flame retardant composites at high temperature.