With the exception of a few synthetic rubbers, most syn […]
With the exception of a few synthetic rubbers, most synthetic rubber products, like natural rubber, are flammable or combustible materials. At present, the method of adding a flame retardant or a flame retardant filler and blending with a flame retardant material to improve flame retardancy are mainly used. In addition, the introduction of a flame retardant group in the monomer during polymerization is also an effective method in the flame retardant technology, and improving the crosslink density of the rubber product also has a good influence on the flame retardancy. The flame retardant technology of rubber is briefly described below.
1. Hydrocarbon rubber
Hydrocarbon rubbers include NR, SBR, BR, IIR, EPR, EPDM, and the like. Although NBR is not a hydrocarbon rubber, its flame retardant technology is very similar to that of hydrocarbon rubber, so it is treated by human hydrocarbon rubber.
Hydrocarbon rubber has an oxygen index of about 19 to 21 and a thermal decomposition temperature of 200 to 500 ° C. Its heat resistance and flame retardancy are generally poor, and most of the decomposition products during combustion are flammable gases.
2. Halogen-containing rubber
The halogen-containing rubber contains halogen elements, the oxygen index is generally between 28 and 45, and the oxygen index of FPM is even above 65. Generally, the higher the halogen content in the halogen-containing rubber, the higher the oxygen index. This type of rubber itself has a high flame retardancy and self-extinguishing from the fire. Therefore, its flame retardant treatment is easier than hydrocarbon rubber. In order to further improve the flame retardancy of the halogen-containing rubber, a method of adding a flame retardant can be usually employed.
3. Miscellaneous chain rubber
The most representative of these rubbers is dimethyl silicone rubber, which has an oxygen index of about 25 and a thermal decomposition temperature of 400 to 6001:. The practical flame retardant route is to increase the thermal decomposition temperature, increase the residue during thermal decomposition, and slow down the generation rate of flammable gas.