Magnesium hydroxide inorganic additive flame retardants are chemical additives with the functions of smoke suppression, flame retardancy and filling, and the smoke generated is non-toxic and non-corrosive.
The flame-retardant mechanism of Magnesium hydroxide
When Magnesium hydroxide flame retardants are added, the polymer releases water as it decomposes and absorbs a lot of latent heat, which in turn reduces the actual temperature of the flame on the material’s surface, slow down the rate of Polymer degradation formation and reduce the production of combustible gases.
Secondly, the large amount of water vapor released in the decomposition process will dilute the concentration of flammable gas and oxygen near the surface of the polymer, making the surface combustion difficult.
The Magnesium hydroxide helps to form a layer of carbon on the surface, which prevents oxygen and heat from entering. The decomposition of magnesium oxide is also a good Refractory, increasing the flame resistance of polymer materials, in order to achieve the isolation of air to prevent combustion purposes. As the decomposition of Magnesium hydroxide by heat can alleviate the three elements of combustion, play a flame retardant role, once the fire disappeared, the combustion can be extinguished by itself.
The decomposition temperature of Magnesium hydroxide is 350 ° C-490 ° C, which is obviously higher than that of Magnesium hydroxide 190 ° C-230 ° C, avoid in the process of processing molding out of crystal water, the performance of the material has an impact. The Magnesium hydroxide has good thermal stability and is relatively stable below 340 â ° C. it begins to decompose after reaching 340 â ° c. the highest decomposition rate occurs at about 430 â ° C, after reaching 490 ° C, the decomposition is finished.
The smoking Magnesium hydroxide
The flame retardancy of Magnesium hydroxide occurs mainly in the solid degradation zone. Although it can reduce the formation of combustibles and smoke, it has little effect on the pre-combustion zone and combustion zone. Therefore, Magnesium hydroxide has little effect on the complete combustion of combustible materials. In addition, the outermost combustion products can dilute and absorb some of the smoke, so the smoke reduction effect of the Magnesium hydroxide is very obvious.