Several commonly used flame retardants and their flame retardant principles
1. Halogen flame retardant:
This is one of the most commonly used flame retardants at present. Its flame retardant principle is that halogen-containing flame retardants generate halogenated hydrogen acid in case of fire. This is a non-combustible gas, and its specific gravity exists around the combusted object, which acts as an oxygen barrier. ; In addition, halogen flame retardants also have the effect of capturing OH radicals.
2. Phosphorus (boron) flame retardant:
Phosphorus (boron)-containing flame retardants mainly form a non-flammable liquid film of phosphorus (boron) acid during combustion, and its boiling point can reach 300°C; at the same time, phosphoric acid further generates metaphosphoric acid, which is a very stable solid phase. The polymer, covering the combustible material, the liquid and solid phase coverings isolate oxygen and prevent combustion.
3. Antimony trioxide and halogen flame retardants are used together:
The mechanism of combined use can be considered to be due to the dehydration of the solid polymer and the carbonization to isolate it from oxygen; and the effect of the oxidant to prevent combustion and release in the gaseous state.
4. Hydroxide flame retardant:
Commonly used is magnesium hydroxide and hydrogenation, the hydroxide compound (containing crystal water) releases crystal water at 220-300 ° C, and absorbs a considerable latent heat of evaporation to cool the combustion material, and the generated water vapor is isolated. The role of air flame retardant. The biggest advantage of this type of flame retardant is that it can be used to formulate low-smoke halogen-free flame retardant cable materials.