How to choose magnesium hydroxide and aluminum hydroxide flame retardant reasonably ?
In modern flame retardant technology, the composite technology of flame retardant is a very important aspect. In addition to maintaining the characteristics of environmental protection, the inorganic composite flame retardant system also has the characteristics of various flame retardants. Therefore, the synergistic effect of different inorganic flame retardants has broad prospects application of flame retardant technology in the future.
Magnesium hydroxide and aluminum hydroxide are the two most important inorganic flame retardants. Its common features are eco-friendly, filling, smoke suppression and flame retardant functions. Aluminum hydroxide is one of the earliest inorganic flame retardants, as a flame retardant, it has the characteristics of no corrosive gas, good stability, long-lasting flame retardant effect, and non-toxicity. However, magnesium hydroxide flame retardant is an inorganic flame retardant currently being actively developed at home and abroad, it not only has the above advantages of aluminum hydroxide, but also significantly better than aluminum hydroxide in terms of smoke suppression performance and thermal stability. The dehydration reaction occurs when magnesium hydroxide is above 350 °C. At the same time, the heat absorption of magnesium hydroxide is 17% higher than that of aluminum hydroxide, which is more conducive to the improvement of flame retardant efficiency. And magnesium hydroxide is more suitable for processing polymers with higher temperatures. It can be seen that different flame retardants have different characteristics and uses. The advantages of Top magnesium hydroxide compared to aluminum hydroxide are as follows:
1.The thermal decomposition temperature of magnesium hydroxide is 330°C, which is 100°C higher than aluminum hydroxide. This is more conducive to increasing the processing temperature, speeding up the extrusion, and shortening the molding time.
2.The neutralization ability of magnesium hydroxide and acid is very strong, and the acid gas generated by the high-polymer during combustion can be neutralized relatively quickly, such as CO2, NOX, SO2 etc.
3.Magnesium hydroxide has high decomposition energy, which will help absorb heat of combustion and improve flame retardant efficiency.
4.Magnesium hydroxide has low hardness, strong smoke suppression ability, and low friction to equipment, which helps to prolong the life of production equipment.
According to the chemical composition, the flame retardant can be divided into two major categories: organic flame retardant and inorganic flame retardant, organic flame retardants are also divided into halogen and phosphorus systems. However, organic flame retardants are gradually being replaced by inorganic flame retardants due to defects such as large smoke and high toxicity of decomposition products. The main varieties of inorganic flame retardants are magnesium hydroxide, aluminum hydroxide, tin oxide, antimony oxide, molybdenum oxide, red phosphorus, ammonium molybdate, zinc borate etc. Magnesium hydroxide and aluminum hydroxide have a large heat absorption due to decomposition and the oxide formed by decomposition is a high temperature resistant substance.