Nitrogen flame retardant
Study on nitrogen flame retardant agent started late and mainly are additives type. The commonly used nitrogen flame retardants are melamine, Melamine cyanurate (MCA). As a new type of high efficient nitrogen flame retardants, they are high efficiency, low toxicity, good heat resistance. Due to the high thermal decomposition temperature, do not worry about materials make flame retardant decomposition and cause failure of flame retardant in the manufacturing. Besides, nitrogen-containing compounds break down produce low corrosion of gas. The polymer materials treated by nitrogen flame retardant has low fuming amount, it shows very good smoke suppression effects.
Effect of the nitrogen flame retardants in the decomposition temperature is reached, it produces gases such as CO2, NH3, N2 and H2O. On one hand, it reduces the air oxygen and the combustible gas concentration when polymer heated to decomposition, this slows down burning rate. One the other hand, noncombustible gases takes away some of the heat, reduce the surface temperature of the polymer, thereby preventing burning.
Its efficiency of flame retardants is not high, availability is not strong and it needs to compound use with other flame retardants when melamine use alone. Through several flame retardants produce synergy to improve the efficiency of flame retardant. Typically, melamine compound use with ammonium Polyphosphate, Pentaerythritol.
Nitrogen-phosphorous flame retardants
Nitrogen-phosphorous flame retardants contain elements of nitrogen and phosphorus, it does not contain halogens, and it does not require antimony trioxide as Synergist. Nitrogen-phosphorus flame retardant is halogen free, low smoke, low toxicity, high efficiency, etc. The surface can generate a uniform layer of carbon foam layer when this flame retardant polymer heated. It plays the role of heat insulation, insulation oxygen, smoke suppression and prevent the phenomenon of droplet, therefore it has a good flame retardant performance.
Flame retardant mechanism of expansion type flame retardant are as follows:
Under lower temperature, ester of multiple alcohol released by acid source can be as dehydration agent of inorganic acid;
Under slightly high of temperature, inorganic acid and multiple alcohol has ester reaction, the system is in melting state;
During reaction process, the produced steam and by gas source produces non-combustible gas makes the molten state system expanding and foam. Meanwhile, multiple alcohol and ester dehydration carbonization to form inorganic and the carbon residue, and system further expansion and foam, finally it forms porous carbon layer. This layer of foam has excellent heat and oxygen and smoke suppression function, as well as has a good flame retardancy. If you have interest, please follow us at OKCHEM Linkedin Page or visit www.okchem.com, thanks!