Production method of flame retardant rubber

Among the many types of rubber products, most synthetic rubber products are flammable or combustible materials. Companies often add flame retardants or flame retardant fillers to rubber to improve flame retardancy. In addition, introducing flame retardant groups into monomers is also an effective method. Increasing the crosslinking density of rubber products also has a certain flame retardant effect.

1. Hydrocarbon rubber. Hydrocarbon rubber includes EPR, NR, BR, SBR, EPDM and so on. Although NBR is not a hydrocarbon rubber, its flame retardant technology is very similar to that of hydrocarbon rubber.

The blending of hydrocarbon rubber and flame retardant polymer can improve the flame retardancy of hydrocarbon rubber to a certain extent. However, it is worth noting that the compatibility and cross-linking of the two material should be considered when blending.

Adding flame retardant is an important way to improve the flame retardancy of hydrocarbon rubber. Organic halogen-based flame retardants are the most common flame retardants. Organic flame retardants including perchlorocyclopentadecane, decabromodiphenyl ether, and chlorinated paraffin. Common inorganic flame retardants are mainly antimony trioxide, in addition to zinc borate, hydrated alumina, and ammonium gasified. Special attention should be paid to the fact that halogen-free flame retardants must not contain free halogens, and the amount of flame retardants should be appropriate.

Studies have shown that increasing the cross-linking density of rubber can increase its oxygen index, thereby improving the flame retardancy of rubber. This method is commonly used in ethylene-propylene rubber to improve its flame retardancy.

2. Halogen-containing rubber. Halogen-containing rubbers all contain halogen elements. The oxygen index is generally between 28-45, and the oxygen index of FPM is even above 65. Generally speaking, the higher the halogen content in halogen-containing rubber, the higher its oxygen index, and the halogen-containing rubber itself has a high flame retardancy and can self-extinguish from fire. 

3. Miscellaneous chain rubber. Dimethyl silicone rubber is the most representative product in this kind of rubber products. Its oxygen index is about 25 and the thermal decomposition temperature is about 400-6001. By increasing its thermal decomposition temperature, increasing the residue during thermal decomposition, and slowing down the generation rate of flammable gas, the flame retardancy of the product can be improved.