Advantages and disadvantages of commonly used flame retardants

In recent years, with the increase in the output of plastic products and the improvement of safety standards, flame retardant materials are more widely used. Generally speaking, flame retardant materials can be divided into organic flame retardant materials and inorganic flame retardant materials.

The organic flame retardant has good flame retardant effect and the addition amount is relatively small. However, organic flame retardants have the drawbacks of generating large amounts of smoke and releasing toxic gases during combustion. Inorganic flame retardants have the advantages of non-toxic, smoke-free, non-volatile and cheap, but the amount of addition is relatively large.

1. Halogen flame retardant

Halogen flame retardants are not only large in output, but also widely used. The material added with the flame retardant can release hydrogen halide and obtain free radicals during the combustion process, thereby preventing the transfer of the combustion chain, and then generating free radicals with low activity to slow down the combustion. Halogen flame retardants are generally used in thermoplastic materials and thermosetting materials. They not only have good compatibility with polymer materials, but also are easy to use. Therefore, they are welcomed by the market and are widely used in automobile, packaging, textile and other industries.

2. Phosphorus flame retardant

Inorganic phosphorus flame retardants mainly include phosphates, red phosphorus, etc. Red phosphorus is widely used. Red phosphorus is a good flame retardant, but in practical applications, red phosphorus flame retardant materials are easy to oxidize and release harmful Highly toxic gas, and dust generated by combustion can easily lead to explosion, and there is a certain danger in resin mixing and molding processing. Therefore, phosphorus-based flame retardant materials are subject to certain restrictions on their use. The improved red phosphorus flame retardant is added with metal hydroxide, which solves the toxicity problem of polymer materials to a certain extent.

3. Nitrogen flame retardant

Commonly used varieties are melamine, melamine cyanurate (MCA), etc., often need to add synergist, nitrogen/phosphorus is a commonly used synergistic flame retardant system, mainly used in PA, PU, PO, PET, PS, PVC and other resins.

Melamine cyanurate is a nitrogen-containing halogen-free environment-friendly flame retardant, especially suitable for unfilled PA6 and PA66, available in powder and granular forms. When the flame-retardant polyamide foam of this product is burned, the formed carbon foam layer protects the polymer and insulates heat and oxygen.

4. Metal oxide flame retardant

Metal oxide flame retardants mainly add inorganic elements with intrinsic flame retardancy to the base material to be flame retardant in the form of simple substances or compounds, fully mix with high polymers in a physically dispersed state, and pass through the gas phase or condensed phase. Chemical or physical changes act as flame retardants.

Aluminum hydroxide is the most popular flame retardant for inorganic hydroxides. It is mainly used for artificial rubber, thermosetting resin and thermoplastic plastics whose processing temperature is below 200℃. Aluminum hydroxide flame retardant plastics are less smoky in flames which is a distinct advantage.

Magnesium hydroxide is an inorganic flame retardant with better thermal stability. It is still stable when it exceeds 300 °C. It is widely used in many artificial rubbers, resins, including engineering plastics and other resins processed at high temperatures. In the polymer system, it plays the role of flame retardant and smoke elimination. When used in combination with ATH, it complements each other, and its flame retardant effect is better than that used alone.

Novista Group supplies APP, MCA, aluminium hydroxide,magnesium hydroxide to global market.