1. Antimony trioxide. Generally speaking, there are two preparation methods, dry method and wet method, with stibnite as raw material. Antimony is oxidized by dry calcination of stibnite and hydrolyzed by hydrochloric acid leaching of antimony trichloride. Antimony trioxide is a white powder with a relative density of 5.67, a melting point of 655 ℃, a boiling point of 1456 ℃, and a refractive index of 2.087. It is insoluble in water, dilute nitric acid and organic solvents, and soluble in concentrated sulfuric acid, hydrochloric acid, alkali (such as sodium hydroxide, potassium hydroxide, etc.) and tartaric acid solutions. The content of antimony trioxide in industrial products shall not be less than 98%.
2. Decabromodiphenyl ether. It is prepared by bromination of diphenyl ether with bromine under the action of halogenated catalyst.
3. Tetrabromobisphenol a. Tetrabromobisphenol A is prepared by bromination of bisphenol A in methanol or ethanol aqueous solution. It is white powder with molecular weight of 543.9, theoretical bromine content of 58.7%, melting point of 181 ℃, relative density of 2.18, weight loss of 1% at about 243 ℃, soluble in acetone, methanol, ethanol, glacial acetic acid and other organic solvents, insoluble in water.
4. Flame retardant PbO. It is prepared by polycondensation of 2,4,6-tribromophenol with initiator. The appearance of PBO is light brown powder, the relative molecular weight is about 6000, the theoretical bromine content is 64%, the softening point is 210-240 ℃, the relative density is 2.07, the initial decomposition temperature is 330 ℃, and the weight loss is 1% and the temperature is 344 ℃. PbO is soluble in tetrahydrofuran and chloroform, and insoluble in water, acetone and ethanol.
5. Flame retardant TCEP. It is obtained by the reaction of phosphorus oxychloride and ethylene oxide under the action of sodium metaaluminate and other catalysts. It is colorless to light yellow oil like transparent liquid.
6. Flame retardant tdcpp. It is obtained from the reaction of cyclopropane and phosphorus oxychloride in dichloroethane solvent with aluminum trichloride as catalyst. Its appearance is colorless to light yellow transparent viscous liquid.
The data of six kinds of commonly used flame retardants are not listed one by one.
