Flame Retardant Mechanism and Flame Retardant Characteristics of Red Phosphorus Flame Retardant
- time:
- 2019-05-11
Flame Retardant Mechanism of Red Phosphorus Flame Retardant
Red phosphorus can be decomposed by heat and react with oxygen in ambient air to form oxyphosphoric acid. This oxyacid has good water absorption, which makes the surface of burning polymer dehydrate and carbonize to form carbonization layer. This can not only isolate the polymer, reduce the release of flammable volatile components, but also possess heat absorption, reduce the heat of oxidation on the surface of polymer, and realize the flame retardant of condensed phase.
When PO free radicals, the pyrolysis product of red phosphorus, enter the gas phase, they can also capture a large number of H and HO free radicals in the combustion flame, cut off the oxidation chain reaction of the flame, and achieve the purpose of gas phase flame retardant.
Flame Retardant Properties of Red Phosphorus
Red phosphorus can absorb water easily in air weight. It can produce H3PO4, H3PO3, H3PO2 and other substances, which make red phosphorus sticky and lose fluidity, and the phosphoric acid produced is more easily absorbed. If red phosphorus exists in the products of high polymer materials, it will absorb moisture and oxidize, which will make the surface of the products gloss and original properties after corrosion, and gradually corrode to the inner layer. At the same time, the oxyacid produced will corrode the processing equipment.
Red phosphorus has poor compatibility with resins, and segregation and sedimentation will occur, which will increase the viscosity of resins, make it difficult to cast, impregnate and operate resins, and also lead to the decline of the properties of synthetic materials.
Long time exposure of red phosphorus to air not only produces phosphorus oxyacid, but also releases highly toxic PH3 gas, which is harmful to the environment and human body.
The hygroscopicity and instability of red phosphorus have adverse effects on the physical properties of plastic products, especially on the leakage of weak current components and the insulation of high voltage components.
Red phosphorus itself, purple red, will make products colored.
Red phosphorus is easily ignited by impact. Dry red phosphorus dust is dangerous to combustion and explosion.
Red phosphorus flame retardant is environmentally friendly in the application process, and has excellent flame retardant effect, which is a rare flame retardant.
