Research on the current situation of various Flame retardants
The present situation of all kinds of flame retardants introduced to you by magnesite company
(a) halogen flame retardants.introduced to you by magnesite company
Halogen flame retardant decomposes to produce halogenated HX,HX through two mechanisms: free radical mechanism: consumption of free radical HO, produced by polymer degradation to reduce its concentration, thus delaying or interrupting the chain reaction of combustion; Surface covering mechanism: hydrogen halide is a kind of incombustible gas with higher density than air. It can form a barrier on the surface of polymer materials, and decrease the concentration of combustible gas, thus slowing down the burning rate and even extinguishing the flame. Usually halogen flame retardants are mainly bromine and chlorine series. Bromine flame retardants have become the most productive in the world because of their low dosage, good thermal stability and high flame retardant efficiency. One of the flame retardants, chlorine is halogenated with bromine, but its flame retardancy is lower than that of bromine. In the last 20 years, chlorine flame retardants have been replaced by bromine flame retardants. Although halogen flame retardant is still one of the most important products, the research on related products is still under way, but because it releases toxic smoke during combustion, it causes secondary harm, which makes people to study new flame retardant-halogen-free flame retardant.
(II) Inorganic flame retardants.introduced to you by magnesite company
Inorganic flame retardants mainly refer to some metal hydroxides and oxide hydrates, which are decomposed to absorb a large amount of heat, thus lowering the surface temperature of the polymer. At the same time, the decomposition of water vapor has the effect of heat storage and release of polymer surface gas concentration. Among non-halogen flame retardants, inorganic flame retardants are an important component, which accounts for a large share of the flame retardants market. The market demand in Japan in 1998 was 74850 tons, accounting for 43 percent of the total demand for flame retardants. At present, inorganic flame retardants have been widely developed and used in China, including hydrated alumina, boron, molybdenum, inorganic phosphorus and zinc, magnesium. Compared with about 19 varieties of transition metal oxides, BAX1091FM series and ultrafine zinc borate HcmetandZ series developed by Alcan Chemical Company of USA not only improve the flame retardancy and smoke suppression, but also improve the processability and mechanical properties of the products. It is worth mentioning that our country is rich in antimony resources and strong in scientific research, which provides a broad prospect for the development of antimony flame retardants in China.
(III) phosphorous flame retardants.introduced to you by magnesite company
There are many oxidized states in phosphorous compounds, and their thermal decomposition products have strong dehydration effect, which carbonize the covered polymer surface and form carbon film, which plays a flame-retardant role. Phosphorous flame retardant also has plasticizing function, it can make flame retardant achieve halogenation. General phosphorus series include inorganic phosphorus and organic phosphorus. Inorganic phosphorus flame retardants include red phosphorus, ammonium phosphate and ammonium polyphosphate; organophosphorus flame retardants include phosphate, phosphite, phosphonate and phosphine salts.