flame retardant additive
Flame retardant mechanism of various flame retardant additives
Flame-retardant additives are additives that can prevent plastic from igniting or inhibit flame propagation. According to the method of use, they can be divided into two types: additive type and reactive type. According to chemical structure, flame retardant additives can be divided into inorganic and organic types. The flame retardant mechanism of various flame retardants is also different.
Halogen-based flame retardant additives include bromine-based and chlorine-based flame retardants. Brominated flame retardants have high flame retardant efficiency and moderate price; halogen-based flame retardants mainly play a flame retardant role in the gas phase. The flame retardant effect of phosphorus and phosphorus compounds from phosphorus compounds in different reaction zones can be divided into flame retardant mechanism in the condensed phase and flame retardant mechanism in the vapor phase. The organophosphorus flame retardant plays a flame retardant role in the condensed phase.
Inorganic flame retardant additives include aluminum hydroxide, magnesium hydroxide, expanded graphite, borate, aluminum oxalate and zinc sulfide based flame retardants. They are non-toxic and low-smoke. Because the heat is decomposed to absorb a large amount of heat in the combustion zone, the temperature of the combustion zone is lowered below the combustion critical temperature, and the self-extinguishing is performed. The metal oxide formed after decomposition has a high melting point, good thermal stability, and covers the surface of the burning solid phase to block heat conduction and Thermal radiation, thus playing a flame retardant role. At the same time, it decomposes to generate a large amount of water vapor, which can dilute the combustible gas and also play a flame retardant role.
As a new type of halogen-free flame retardant, silicone flame retardant additive is unique in its excellent flame retardancy, moldability and environmental friendliness. Silicone flame retardants are silicone oil, silicone resin, functional silicone, polycarbonate-siloxane copolymer acrylate-silicone composite, and silicone gel.www.china-zhufengchem.com