Halogen-free flame retardants and halogen-containing flame retardants have significant differences in many aspects. The following is a detailed comparison of the two:
First, ingredient differences
Halogen-containing flame retardants: These refer to flame retardants containing elements such as Cl, Br, and F. They are mainly halogen-containing polymers or flame retardant mixtures composed of halogen-containing flame retardants, such as antimony trioxide and decabromodiphenyl ether (bromine-antimony grade flame retardants).
Halogen-free flame retardants: They are a type of chemical substances that do not contain halogen elements, usually composed of nitrogen, phosphorus, silicon and other elements, such as phosphorus-based flame retardants, intumescent flame retardants, inorganic flame retardants (aluminum hydroxide, magnesium hydroxide, etc.), silicon-containing flame retardants and bio-based flame retardants.
Second, comparison between environmental protection and safety
Halogen-containing flame retardants: When heated, they produce a large amount of smoke and toxic corrosive hydrogen halide gases. These gases are not only harmful to human health but may also corrode instruments and equipment. A large proportion of fatal accidents in fires are caused by thick smoke and toxic gases produced by materials.
Halogen-free flame retardants: They produce little smoke when burning, do not generate corrosive or toxic gases, and pose less harm to the environment and human health. This complies with the requirements of current environmental protection and safety regulations, such as the EU’s RoHS Directive and REACH regulation.
Third, comparison of flame retardant effect and performance
Halogen-containing flame retardants: They are low in price, have good stability, require a small addition amount, have good compatibility with synthetic resin materials, and can maintain the original physical and chemical properties of flame retardant products. Halogen elements can react with free radicals in the combustion products during the combustion process to form stable halides, thereby inhibiting the spread of flames.
Halogen-free flame retardants: After special surface treatment, they are easy to disperse in plastic materials, do not precipitate, and have excellent flame retardant effects. Meanwhile, halogen-free flame retardants can also enhance the thermal stability and heat resistance of materials and extend their service life. However, compared with halogen-containing flame retardants, halogen-free flame retardants may require a larger addition amount to achieve the same flame retardant effect, and may have certain impacts on the mechanical and processing properties of materials.
Fourth, Application fields and trends
Halogen-containing flame retardants: Although halogen-containing flame retardants have certain advantages in terms of flame retardant performance, their application scope is gradually being limited due to their environmental protection and safety issues. Especially in some fields with high requirements for environmental protection and safety, such as electronics and electrical appliances, building materials, etc., the use of halogen-containing flame retardants is gradually decreasing.
Halogen-free flame retardants: With the enhancement of environmental awareness and the improvement of regulations, the application scope of halogen-free flame retardants is gradually expanding. They are widely used in fields such as electronics and electrical appliances, building materials, and transportation to meet the requirements of environmental protection and safety.
