It is understood that: Melamine cyanurate (MCA) is a salt synthesized from melamine and cyanuric acid. It is a nitrogen series flame retardant and is available in powder and granular forms. Two forms, odorless, melting point is about 350°C. MCA has good dispersion and lubricity, and has little impact on the processing properties and physical and mechanical properties of the polymer. This product is economical to use, highly efficient, has excellent electrical and mechanical properties, does not discolor, has low smoke and is low in corrosion.
Flame retardant principle of melamine cyanurate:
Melamine cyanurate (MCA) sublimes and absorbs heat to reduce the surface temperature of the polymer and eliminate Air can accelerate dissolved droplets, thereby taking away heat and combustibles, changing the thermal-oxygen degradation process and causing rapid carbonization to form non-combustible carbonaceous materials. These carbonaceous materials expand and foam to cover the surface of the substrate, forming an insulating layer. It eliminates contact with air and the escape of combustibles, which can effectively prevent the material from continuing to burn. At the same time, the non-combustible gas produced by decomposition causes the material to expand to form an expansion layer, which can greatly reduce the thermal conductivity and facilitate the material’s self-extinguishing from fire. .
The details are as follows:
The molecule of MCA flame retardant is composed of melamine MA and cyanuric acid CA molecules through hydrogen bonding, and then the two molecules can move in three directions. 9 hydrogen bonds are formed, thus self-assembling into a large-area hydrogen bond network. The spatial structure has good stability, resulting in better heat resistance. After the MCA flame retardant reaches 350 degrees, it begins to decompose to form MA and CA. This process requires absorbing a large amount of heat from the polymer and reducing the surface temperature of the substrate.
When the flame retardant system containing MCA flame retardant burns, it can generate a large number of dense honeycomb carbon layers on the surface of the flame retardant material. After foaming, an expanded coke protective layer with combustion properties is formed. The carbonized layer forms an excellent barrier layer between the polymer and the combustion area, limiting the heat release rate, blocking the supply of oxygen, preventing further combustion of the flame retardant material, and minimizing the amount of smoke and harmful gases.
PS: The flame retardant mechanism of melamine cyanurate (MCA) is completely different from that of phosphorus, silicon and halogen flame retardants. It is usually different from other phosphorus, inorganic aluminum hypophosphite and organic diethyl hypophosphites. After aluminum phosphate, aluminum hydroxide, etc. are compounded, the flame retardant method will change greatly. Generally, it needs to be compounded with phosphorus-containing or piperazine pyrophosphate, triazine carbon-forming agent, pentaerythritol, etc. to decompose the phosphorus-carbon flame retardant. The covering foams and expands, which can prevent the exchange and convection of heat and outside oxygen.
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