What is NBR hose

Nitrile Butadiene Rubber (NBR) is a kind of synthetic Rubber, which is a copolymer polymerized from acrylonitrile and Butadiene monomer. It has such advantages as excellent oil resistance (especially alkane oil), high wear resistance, good air tightness, good heat resistance, strong adhesion and good aging resistance.

Disadvantage is low temperature resistance, poor ozone resistance, poor insulation, slightly lower elasticity, should not be used as insulation materials.

Germany first began commercial production in 1937.

Although the chemical and physical properties of NBR vary with the amount of cyanogen in the polymer, NBR remains resistant to oil, gasoline and other solvents.

The higher the cyanide content in the polymer, the stronger the corrosion resistance and the worse the elasticity.

Nitrile butadiene rubber is used in the manufacture of oil hose, flame retardant conveyor belt.

Secondly, it is used for sealing devices in automobile industry, as well as oil-resistant gaskets, gaskets, sleeves, flexible packaging, soft rubber tubes, printing and dyeing cots, cable rubber materials, and protective gloves in nuclear industry.

Nitrile rubber has a strong ability to adapt to temperature, can be in - 40 to 108 ° C temperature range to work properly, this feature makes the nitrile rubber is widely used in the aviation industry.

Nitrile rubber can also be cast into a variety of products.

The high elasticity of NBR makes it the raw material for the manufacture of disposable laboratory gloves.

Nitrile rubber is also more resistant to oil and acid corrosion than natural rubber.

Although lower in elasticity and strength than nr, NBR is several times more resistant to corrosion than nr.

Produce

In the production of hot NBR, emulsifiers, 2-acrylonitrile, various butadiene monomers (including 1, 3-butadiene, 1, 2-butadiene), initiators and catalysts are added to the polymerization container.

Water as a medium in the reaction container, the container is heated to 30-40 ℃ to prompt the polymerization reaction and promote the formation of side chain.

Due to the addition of a variety of monomers that can participate in the polymerization reaction in the production, with the change of the concentration of each monomer or the change of reaction conditions, the final polymer type will also change, and the obtained polymer type is also complex.

It is impossible to find simple repeating units in the final product.

For this reason, NBR as a general polymer does not have an official IUPAC name.

Part of the polymerization reaction can be expressed by the following equation: 1, 3-butadiene +1, 3-butadiene + 2-acrylonitrile +1, 3-butadiene +1, 3-butadiene butadiene rubber

Polymerization usually takes 5-12 hours and yields up to 70%. When the reaction approaches the end, chain terminator (e.g., dimethyl dithiocarbamic acid and diethylamine) is added to the container to react with the remaining free radicals to terminate the polymerization.

The unreacted monomer is removed by a mud stripper.

In the production of thermal process of nitrile rubber and nitrile rubber is very similar to the process of polymerization reaction vessel was heated to 5-15 ℃ rather than 30 to 40 ℃.

At lower temperatures, the number of branched chains in the polymer can be greatly reduced.

The main difference between cold and hot NBR is the number of branched chains.