Flame retardant principle of cotton flame retardant fabric
After the fabric is impregnated with the flame retardant liquid, the pre-shrinkage formed by the flame retardant and the guanamine penetrates into the amorphous region and the gap of the fiber, and then the methylation of the NH3 and the pre-shrinkage during the ammonia-smoke is performed. The flame-retardant polymer is formed inside the fiber and then oxidized to stabilize.
The phosphorus-containing compound causes the fiber to undergo a dehydration reaction during pyrolysis. The phosphorus-containing flame retardant is first decomposed into a non-volatile phosphoric acid or polyphosphoric acid in the fiber pyrolysis temperature range to dehydrate the fiber (-OH) to carbonize the fiber. The fabric impregnated with the flame retardant produces a P-N synergistic effect during the ammonia smoking process due to the formation of a highly crosslinked polymer of phosphorus dioxide/nitrogen inside the cellulose. The P-N bond performance (polarity) is higher than the P-O bond, which enhances the reaction performance of the phosphorus compound with -OH, thus producing flame retardant properties.
The so-called "flame retardant" does not mean that the fabric has the characteristics of not being ignited by the flame after being finished by the flame-retardant fabric, but the fabric is reduced in flammability under the flame, the area of the burning portion is reduced and the burning speed is lowered. The combustion is stopped after the flame leaves, and has self-extinguishing performance.