Mechanism of flame retardant:
Covering theory of flame retardants in > 500 ℃ in the fiber surface form a blanket has isolation effect, in addition to hinder the supply of O2, also prevent flammable gas spread outward, so as to achieve purpose of flame retardant, such as borax and boric acid.
Gas theory: first, the flame retardant can decompose the non-flammable gas at the combustion temperature, and dilute the flammable gas concentration to produce the flame concentration below; The other is that the flame retardant can be used as a high activity base transfer in the heating condition, thus preventing the free radical reaction.
Heat theory: the first is that the flame retardant changes at high temperature, such as melting and sublimation, thus preventing the burning and spreading; The other is the rapid heat dissipation of the fibers, making the fabric less than the burning temperature.
Catalytic dehydration theory: mainly refers to the process of pyrolysis of fiber. Because the flame retardant can cause the cellulose molecular chain to undergo rapid and massive dehydration before the rupture, even some cross-linking effect can prevent the formation of left-lateral glucose and inhibit the flame combustion.