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Nitrile rubber must understand those things!!

release time:2022-06-22publisher:

What is nitrile rubber?


Nitrile butadiene rubber (NBR), is a copolymer of acrylonitrile and butadiene monomer polymerization, mainly using low temperature emulsion polymerization production, excellent oil resistance, high wear resistance, good heat resistance, strong adhesion. Its disadvantages are poor low temperature resistance, poor ozone resistance, poor insulation performance, slightly lower elasticity.


Butadiene rubber production


Emulsifiers (soap), acrylonitrile, various butadiene monomers (including 1, 3-butadiene, 1, 2-butadiene), activators and catalysts that generate free radicals are added to polymerization containers in the production of hot BUtadiene rubber. Water is used as the reaction medium in the container. The tank is heated to 30 -- 40°C to facilitate polymerization and the formation of branched chains in the polymer. Because NBR production involves several monomers capable of propagating the reaction, the composition of each polymer may vary (depending on the concentration of each monomer added to the polymerization tank and the conditions in the tank). A repeating unit found throughout the polymer may not be present. Therefore, the generic polymer does not have an IUPAC name.


The monomer reaction is usually allowed for 5 to 12 hours. The polymerization is carried out to a conversion rate of about 70% before the addition of "stoppers" such as dimethyl dithiocarbamates and diethyl hydroxylamine react with the remaining free radicals. Once the latex is "terminated", the unreacted monomer is removed by steam in the slurry stripper. The recovery of unreacted monomer was close to 100%. After the monomer is recovered, the latex is passed through a series of filters to remove excess solids before being fed into a mixing tank, where it is stabilised with antioxidants. The polymer latex was coagulated with calcium nitrate and aluminum sulfate. And other coagulants in aluminum cans. The congealed material is then washed and dried into breadcrumb rubber.




Performance of nitrile butadiene rubber


Nitrile butadiene rubber has better heat resistance, its heat resistance is better than natural rubber and styrene butadiene rubber, long-term use temperature can reach 100 degrees Celsius, 120 degrees Can be used for 40 days.


1. The rubber is endowed with better physical and mechanical properties and wear resistance through reinforcement.


2. When the acrylonitrile content of ACRYlonitrile butadiene rubber is 39%, the air tightness is similar to IIR rubber, and the air tightness is better.


3. Low temperature flexibility is good.


4. Excellent antistatic performance.


5. The plasticizing effect is better with polar lipids.


6. Good compatibility with polar substances.


7. Low self viscosity, high heat generation in mixing process.




Nitrile butadiene rubber and 12 kinds of rubber and plastic materials used


1. Natural rubber: nitrile rubber and natural rubber can improve the processing performance and low temperature resistance of nitrile rubber; It should be noted that, with the increase of the amount of natural rubber, and the oil resistance of rubber 2YLYY713-LYY will decrease, so we must reasonably control the amount of natural rubber.


2. Styrene butadiene rubber: nitrile rubber and styrene butadiene rubber can improve the low temperature resistance of nitrile rubber; The price of styrene butadiene rubber is low, adding part of styrene butadiene rubber can also reduce the production cost of nitrile rubber products.


3. Butadiene rubber: nitrile rubber and butadiene rubber can improve the wear resistance, flexure resistance and low temperature resistance of nitrile rubber.


4 epDM rubber: nitrile rubber and EPDM can improve the low temperature resistance of nitrile rubber, weather aging resistance and ozone aging resistance.


5. Neoprene rubber: The combination of NBR and neoprene can improve the weathering resistance of NBR.


6. Chloroether rubber: Nitrile rubber and chloroether rubber can improve the ozone resistance of nitrile rubber.


7 chlorinated butyl rubber: nitrile rubber and chlorinated butyl rubber can improve the aging resistance of nitrile rubber, corrosion resistance.


8. Chlorinated polyethylene rubber: Nitrile rubber and chlorinated polyethylene rubber can improve the performance of nitrile rubber ozone aging resistance, weather aging resistance and aging discoloration.


9 polyvinyl chloride: nitrile rubber and PVC can improve the combustion resistance of nitrile rubber.


10.ABS resin: Nitrile rubber and ABS resin can improve the wear resistance of nitrile rubber.


11 polyamide resin: nitrile rubber and polyamide resin can improve the wear resistance of nitrile rubber, low temperature resistance, oil resistance and solvent resistance.


12. Recycled rubber: the use of nitrile rubber and recycled rubber can significantly reduce the production cost of nitrile products. In actual production, the combination of NBR and NBR can better ensure the oil resistance of rubber products; Adding proper amount of recycled tire rubber into nitrile wear-resisting products and conductive products can reduce more raw material cost.


The main use of nitrile rubber


Because of its excellent oil resistance and physical and mechanical properties, nitrile rubber is widely used in the manufacture of various oil resistant rubber products. Such as O-ring, gasket, hose and fuel tank lining glue, printing drum, oil tank lining, insulating floor board, oil resistant sole, hard rubber parts, fabric coating, pipe thread protection layer, pump impeller and wire sheath, adhesive, food packaging film, rubber gloves and other fields


China's nitrile rubber is mainly used in military industry, automobile, aviation industry, oil tank and other oil-resistant parts, but also used in seals, transmission belts, hoses and plastic modified materials. The amount is increasing year by year.


The second largest application field of NBR is sealing rubber products, widely used in aerospace devices, transformers, liquefied petroleum gas pipelines and other aspects, among which automotive seals account for about 50% of the total consumption of sealing rubber products. It is also used to make oil-resistant rubber board, printing rubber roller, flame retardant hydraulic hose in coal mine, oil tank, oil tank, oil container, oil-resistant rubber shoes and so on.


It is mainly used in aviation, automobile, printing, textile and machinery manufacturing. Due to the development of NBR modified varieties, NBR application prospects have been expanded. To sum up, there are mainly: manufacturing fuel tubing, grease cloth, oil seal, refueling pipe, oil resistant rubber parts and various products in contact with oil. NBR has good compatibility with PVC and acetic acid resin, so it is often mixed with resin to modify the material. PVC is often used to improve processing properties and impact resistance, phenolic resin is used to obtain a flexible material, the manufacture of asphalt mixture after the fluidity of the material.


Nitrile rubber is mainly used for making oil resistant products, such as oil resistant tubing, tape, rubber film and large oil capsule, etc. It is often used for making all kinds of oil resistant molded products, such as O-ring, oil seal, leather bowl, diaphragm, valve, bellow, rubber hose, seals, foam, etc., and also used for making rubber plate and wear-resistant parts


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