Flame retardant is a kind of chemical additive which plays an important role in the fields of industry and life. It can restrain the flammability of the material and achieve the ideal flame retardancy of the material. Also people's lives and property security also brings a guarantee. The specific role of flame retardants include the following aspects.

1, non-flammable gas suffocation effect

Flame retardants will decompose after burning non-flammable gas, combustible gas will be decomposed out of the combustible gas concentration diluted to the lower limit of combustion. It also dilutes the oxygen concentration in the combustion range and successfully hinder the spread of the fire.

2, endothermic effect

Any burning in a relatively short period of time to release the heat is limited, if we can in a short time to absorb part of the heat emitted by the heat, then the flame temperature will be reduced to the combustion surface and the role of gasification has been Flammable molecules into free radicals will reduce the heat, the combustion reaction will be a certain degree of inhibition. Under high temperature conditions, the flame retardant undergoes a strong endothermic reaction, absorbing some of the heat released by the combustion, reducing the temperature of the combustible surface, effectively suppressing the generation of flammable gases and preventing the spread of combustion. The flame retardant mechanism of Al (OH) 3 flame retardant is to improve its flame retardancy by increasing the heat capacity of the polymer and absorbing more heat before it reaches the thermal decomposition temperature. Such flame retardant to give full play to its combination of water vapor large endothermic characteristics, improve its own flame retardant capacity.

3, non-flammable gas suffocation effect

Flame retardant decomposition of non-flammable gas heating, combustible gases will be decomposed out of the concentration of diluted gas below the lower limit of combustion. At the same time, it also has a dilution effect on the oxygen concentration in the combustion zone, preventing the combustion from continuing and achieving the function of flame retardancy.

4, inhibit the chain reaction

According to the chain reaction theory of combustion, it is the free radicals that are required to sustain combustion. Flame retardants can act on the gas-phase combustion zone, capture the free radicals in the combustion reaction, thereby preventing the spread of the flame, so that the combustion zone flame density decreased, and finally the combustion reaction rate down until the termination. Such as halogen-containing flame retardants, its evaporation temperature and the polymer decomposition temperature of the same or similar, when the polymer is heated decomposition, the flame retardant also volatilize out. At this point halogen-containing flame retardants and thermal decomposition products at the same time in the gas-phase combustion zone, the halogen will be able to capture the combustion reaction of free radicals, thereby preventing the spread of the flame, the combustion zone flame density decreased, the final combustion reaction rate until terminated .