What Is The Trend Of Halogen-free Flame Retardants For Polyamide?
Polyamide halogen-free flame retardants are definitely the best choice in the future, and the main choices are red phosphorus and melamine salts.
China is the world's largest country of phosphorus resources, so red phosphorus has a huge cost advantage. Red phosphorus has high flame retardant efficiency and is widely used. Manufacturers of environmentally friendly flame retardants know that red phosphorus is thermally decomposed to form phosphoric acid. On the one hand, phosphoric acid acts as a dehydrating agent to promote the formation of carbon. The formation of carbon reduces the heat transfer from the flame to the condensed phase; on the other hand, phosphoric acid can absorb heat because it prevents the oxidation of CO to CO2 and reduces the heating process. Use endothermic and condensed phase flame retardant mechanism for flame retardant.
However, the 2010 Panasonic incident make people worry about the security of red phosphorus flame retardants, because red phosphorus will cause certain potential safety hazards to the performance of the product. On the other hand, the color of red phosphorus also limits it to dark polyamide products such as black or red. Therefore, melamine salt is generally used for light-colored or transparent halogen-free flame-retardant polyamide.
Melamine salts mainly include melamine cyanurate (MCA), melamine polyphosphoric acid (MMP), etc., which have the advantages of low toxicity, low corrosion, high flame retardant efficiency, and no conflict with additives. When used alone, PA can reach UL 94 V-0. After the melamine salt is thermally decomposed, part of the heat is taken away, and the surface temperature of the PA decreases. From the perspective of the gas phase, from the perspective of the condensed phase, decomposition easily releases incombustible gases such as ammonia nitrogen, nitrogen, nitrogen oxide, water vapor, dilutes the concentration of combustible gas and combustion-supporting gas, hinders the further combustion of PA, proposes the degradation of PA materials, and promotes The formation of residual carbon protects the interior of the matrix.
When using these flame retardants, in order to reduce costs and maximize the flame retardant effect, environmentally friendly flame retardant manufacturers will mix according to the synergistic effect, such as halogen flame retardants with gas phase flame retardant effects, solid flame retardants Effective phosphorus flame retardants form a complete gas-solid flame retardant system; nitrogen-based flame retardants can promote the carbonization of phosphorus compounds.
In any case, when pepople ask what is the development trend of halogen-free flame retardants for polyamide, red phosphorus and melamine salts are definitely the best choice.
Novista Group supplies APP, MCA, aluminium hydroxide,magnesium hydroxide to global market.