Flame Retardant and Smoke Suppression Properties of Aluminum Hydroxide

The endothermic dehydration process of aluminum hydroxide delays the combustion of the polymer, which slows down the combustion rate. At the same time, the water vapor released not only dilutes the combustion gas, but also participates in the reaction of the condensed phase. The diluting effect directly produced by the endothermic decomposition also makes aluminum hydroxide have a smoke suppressing function. The alumina formed by decomposition together with other carbides forms a flame retardant barrier, which can reduce the burning speed and prevent the flame from spreading.

The flame retardant mechanism of aluminum hydroxide:

1. Endothermic effect: dehydration and absorption at 200-350°C, inhibiting the temperature rise of the polymer.

2. Carbonization: Aluminum hydroxide flame retardant produces strong dehydrating substances under combustion conditions, which makes carbonization of plastics difficult to produce flammable volatiles, thereby preventing the spread of flame.

3. Covering effect: AL2O3 protective film is formed on the surface of combustible materials after dehydration of aluminum hydroxide. Isolate oxygen to prevent further combustion.

4. Dilution: After filling aluminum hydroxide in organic polymers such as rubber, plastic and resin, the concentration of flammable substances in the composite material will decrease; in addition, water vapor released after thermal decomposition of aluminum hydroxide will dilute flammable gas And oxygen concentration can effectively slow down or prevent combustion