The so-called "flame retardant", not the flame retardant finishing of the textiles in contact with the fire will not burn, but the fabric in the fire as much as possible to reduce its flammability, slow the spread of the speed, not the formation of large area of combustion Leave the flame, can quickly self-extinguishing, no longer burning or smoldering. Flame retardants and combustion are closely related. Flame retardant manufacturers analysis of the latest view that combustion should have four elements - fuel, heat, oxygen, chain reaction. And usually the fabric can be divided into three stages of combustion, that is, thermal decomposition, heat ignition, hot ignition, the different stages of the four elements of the combustion phase with the corresponding resistance to resist, to form a variety of flame retardant mechanism And interrupt the flame retardant mechanism.
According to the existing research results, the flame retardant mechanism can be roughly divided into the following.
(1) flame retardant manufacturers analysis of endothermic reaction: that is, in addition to heat. In the case of a flame retardant having a high heat capacity, an endothermic decomposition reaction such as phase change, dehydration or dehydrohalogenation occurs at a high temperature, the temperature of the fiber surface and the flame region is reduced, the rate of the pyrolysis reaction is slowed down, and the generation of the flammable gas is suppressed.
(2) the formation of free radicals: flame retardant into a gas, the gas in the flame area to capture a large number of high-energy hydroxyl radicals and hydrogen radicals, reduce their concentration, so as to inhibit or interrupt the combustion of the chain reaction, Play a flame retardant role.
(3) melting theory: the role of heat and energy, the flame retardant into a molten state, the formation of impermeable coating on the surface of the fabric, a condensed phase and a barrier between the flame, can block the heat conduction and heat radiation, Reducing the heat fed back to the fibrous material, thereby inhibiting thermal cracking and combustion reactions.
(4) particle surface effect: If the combustible gas mixed with a certain amount of inert particles, it can not only absorb the heat of combustion, reduce the flame temperature, but also in the surface of the particles on the gas phase combustion reaction in a large number of high energy hydrogen radicals, Into a low-energy hydroperoxide radical, thereby inhibiting gas phase combustion.