NBR rubber roller and wheels has excellent oil resistance. Butadiene monomers can be copolymerized into three different chain structures: cis, trans and 1,2-alkyl. In a typical NBR structure, trans accounts for about 78%. Due to the cyano group contained in the NBR molecular chain structure, oil resistance (such as resistance to mineral oils, liquid fuels, animal and vegetable oils and solvents) is superior to natural rubber, neoprene and styrene-butadiene rubber. Compared with other rubbers, NBR has a wider range of use temperature, its long-term use temperature is 120oC, and NBR has good low temperature resistance, and the minimum glass transition temperature can reach -55oC.
NBR rubber rollers and wheels has good chemical resistance and good processing performance. With the increase of the relative density of acrylonitrile in its structure, the vulcanization speed is accelerated, and the tensile strength performance is improved, but the resilience performance is decreased, and the cold resistance is deteriorated. Because the cyano group in NBR is easy to be polarized by electric field, the dielectric properties are reduced, and it is a semiconductor rubber. NBR can be divided into 5 categories according to the level of ACN content: ultra-high, high, medium-high, medium and low acrylonitrile. Production methods are divided into continuous and batch polymerization methods. The continuous polymerization method is usually used for low-variety and high-volume production with low consumption. The batch polymerization method is suitable for multi-variety and small batch production. So far, there is no sign of a mutual substitution trend.
The performance and basic performance of NBR rubber roller and rubber wheel
Nitrile rubber is a light brown elastomer with a molecular weight of about 700,000. Due to the strong polar CN group, it has excellent stability to aliphatic hydrocarbon oils and gasoline. And according to the different division of ACN sense:
1. The ACN content of extremely high two-coal nitrile rubber is more than 43%;
2. The ACN content of high acrylonitrile rubber is 36%-42%;
3. The ACM content of medium and high propylene wax rubber is 31%-35%;
4. The ACN content of the two dilute nitrile rubbers is 25%-30%;
5. The ACN content of low acrylonitrile rubber is below 24%.
Because NBR is a polar unsaturated carbon chain rubber, its compounding and processing are similar to that of nitrile butadiene rubber, which has the same commonality to unsaturated rubber, but it also has some characteristics brought by the polarity of ACN group.
General performance of NBR rubber roller rubber wheel
Nitrile-butadiene rubber has better heat resistance, and its heat resistance is better than that of natural rubber, butadiene rubber and styrene-butadiene rubber. The long-term use temperature can reach 100oC, and 120oC can be used for 40 days.
①Ozone resistance is worse than CR and better than NR;
② Endow the rubber with better physical and mechanical properties and wear resistance through reinforcement;
③ When the acrylonitrile content of nitrile rubber is 39%, the air tightness is equivalent to that of IIR rubber, and the air tightness is better;
④Low temperature flexibility is general;
⑤Excellent antistatic performance;
⑥ The use of polar lipids has better plasticizing effect;
⑦Good compatibility with polar substances, such as PVC, acid resin, nylon;
⑧Poor packability, low self-adhesion, and large heat generation during mixing.
Although nitrile rubber rollers has excellent physical and mechanical properties and processing properties, its long-term performance in acidic gasoline and high temperature (150oC) environments is not as good as fluorine-like rubber and acrylic acid rubber. For this reason, German companies, Canadian companies and Japanese companies Developed hydrogenated nitrile rubber (HNBR) with excellent performance. In addition, it has also developed super-cold-resistant and high-purity nitrile-butadiene rubber and shuttle-based nitrile-butadiene rubber (XNBR).
Excellent oil resistance of NBR rubber rollers
Nitrile rubber rollers and wheels are one of the most representative rubbers with excellent comprehensive properties such as oil resistance, physical and mechanical properties, and chemical resistance. Effective use of these properties can make them suitable for various applications. Among general-purpose rubbers, NBR rubber has far better resistance to benzene, petroleum-based oils and non-polar solvents than non-polar rubbers such as NR, SBR, and IIR, and is also better than polar CR. Solvent and polar oil resistance is not good enough.
Effect of ACN Content on the Properties of NBR Rubber Roller and Rubber Wheel
With the increase of ACN content, the polarity of NBR increases, the chain flexibility decreases, the interaction force between chains increases, the content of double bonds in the molecular chain decreases, and the degree of saturation increases, which also causes a series of changes in properties. Airtightness, air tightness and wear resistance are improved, while processability and cold resistance are decreased. To this end, the NBR with appropriate ACN content should be selected according to the type and use conditions of nitrile rubber-like rubber products.
Post time: Apr-24-2022