Halogen Flame Retardant

Halogen Flame Retardant

Halogen flame retardants are a class of flame retardants that contain halogen elements. Alfa Chemistry offers a wide range of halogen-based flame retardant products, including chlorine-based and bromine-based flame retardants.


The four halogen elements of the halogen system, F, Cl, Br, and I, all have flame retardancy, and the flame retardant effect is enhanced in the order of F, Cl, Br, and I. Among them, Iodine-based flame retardants are the strongest.

In fact, only chlorine-based and bromine-based flame retardants are widely used, while fluorine-based and iodine-based flame retardants are rarely used. Because the C-F bond in the fluorine-containing flame retardant is too strong to effectively capture free radicals. The C-I bond of the I-containing flame retardant is too weak and easy to be destroyed, which affects the polymer properties (such as light stability).

Halogen Flame Retardant Mechanism

Halogen Flame Retardant

The working mechanism of halogen-based flame retardants is mainly gas phase flame retardant. Halogen flame retardants (RX) work by interfering with the combustion cycle in the gas phase, where key combustion free radicals (•OH and H•) are removed by decomposed halogenated species (equation on the right) and thus effectively interfere with their oxidation. The production of non-combustible gas will dilute the concentration of oxygen and flammable gases in the air, thus playing a flame retardant role.

Advantages And Disadvantages of Halogen Flame Retardants

  • The biggest advantages of halogen flame retardants are high flame retardant efficiency, low dosage and relatively low cost. In addition, brominated flame retardants have good compatibility with materials and can maintain the original physical and chemical properties of flame retardant products.
  • Halogen flame retardants will emit corrosive and toxic gases such as hydrogen halide and thick smoke at high temperature and open fire, which is not conducive to environmental protection and ecological safety.

Application Field

Wire and cable, home appliances and 3C industries, automobiles, construction, electrical switches, adhesives, etc.

Research Information

Semi-aromatic brominated flame retardant

Ou et al. synthesized a novel semi-aromatic brominated flame retardant, tetrabromophthalate di-2-ethylhexyl ester (TBPDO). In addition to being flame-retardant, it can significantly improve the impact strength of flame-retardant styrene plastics, including HIPS, ABS, and SMA. In addition, the mixture of TBPDO with phosphate or brominated oligomers can improve the tensile strength and melt flow properties of engineering plastics such as PC, PBT, and modified PPO.

Chemical structure of (TBPDO)Chemical structure of (TBPDO) [1]

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  1. Li Chen, et al. (2010). "A review on flame retardant technology in China. Part I: development of flame retardants," Polym. Adv. Technol. 21(1), 1–26.
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