橡胶原材料知识-生胶编-第一章 丁腈橡胶-NBR

Mackintosh

丁腈橡胶的英文俗称为“Nitrile”，它是丁二烯与丙稀腈的聚合物，行业上也称“Buna N”。丁腈橡胶具有优越的物理机械性能，高度的耐润滑油、油脂、燃料油和相对较低的成本，被广泛用于工业密封制品材料。丁腈橡胶的物理、化学性能决定于其丙烯腈的含量，市场上，有许多不同类型，等级的丁腈橡胶基于不同的丙烯腈含量和不同的粘度，较为普通的丙烯腈含量范围为18%至50%。一般情况下，一个标准的NBR配方中ACN含量为33%~34%。低ACN 含量的NBR赋予优越的抗低温屈挠性能，但相对的耐燃料油，油脂性能受到限制。相反，高ACN含量的NBR赋予优越的耐油性，随着极性基因ACN含量的上升，抗低温屈挠性能变差，抗压缩永久变形变差，但硬度变高和拉伸强度、热老化性能、抗空气渗透、耐油、非极性溶液性能变好。
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NBR中的丁二烯基因含有不饱和的双键，故NBR可用硫磺加硫，也可用过氧化物或其它进行硫化，过氧化物硫化的NBR橡胶赋予比硫磺硫化更为优越的老化性能（大约275℉）和低的压缩永久变形，但加工较为困难，成本越高。同样，正是因为这不饱和的双键，导致NBR相对较差的老化，耐氧，臭氧，阳光，气候性能，所以NBR产品不能储存在这些环境的周围。

+ K. t; @4 [! V/ d2 z( b尽管如此，NBR橡胶在-40℉到+225℉温度内相通对稳定，在这温度范围内，通过配合，NBR可提供优越的拉伸强度，撕裂、压缩永久变形性能以及耐油性。
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! ?% u, D/ p; l# p5 k; o% @美国材料试验协会ASTM D2000和SAE J 200中有关NBR的规范级别为BF，BG，BK CH。

NBR推荐使用于汽油、燃料油、硅油、硅油脂、乙烯基乙二醇，100℃以下水中和一些非极性的化学试剂中，不推荐使用于高极性溶剂（如丙酮、丁酮、苯、甲苯、二甲苯等）中，芳香烃刹车油，强酸或直接暴露在臭氧和阳光下。  
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/ d( i4 _+ U9 l  q) n' FNitrile rubber (NBR) is the general term of acrylonitrile- butadiene terpolymer. It is also called Buna-N. Nitrile rubber is a very commonly used material for seals because of its good physical properties, good resistance to lubricants and greases and fuels and its relatively low cost. Nitrile rubber physical and chemical resistance properties are determined by the acrylonitrile(ACN). There are many different nitrile rubber grades of different acrylonirile (ACN) content and different viscosity of the raw polymer. The general acrylonitrile (ACN) content of nitrile rubber is from 18% to 50%. A standard, general-purpose nitrile compound usually contains 33%-34% ACN. Low ACN content nitrile rubber ensures good flexibility at low temperatures, but offers limited resistance to oils and fuels. High ACN content nitrile rubber exhibit less swell in fuels and lubricants. Due to polar segment, as the ACN content increase, the low tempreature flexibility reduces, and the compression set resistance reduces, but the tensile strength, hardness, abrasion resistance, heat resistance and gas impermeability are also improved as well as fuel and oil and non-polar fluid resistance.

As the butadiene segment contains the unsaturated double bond, nitrile rubber can use sulfur or peroxide or others as crosslinking. Peroxide cured nitrile rubber imparts good heat resistance (about 275℉) and good compression set than sulfur cured, but the price is higher and the process is more difficult.  Also just for this unsaturated double bond, nitrile rubber impart general or poor heat, oxidation , ozone, sunlight, weathering resistance. So nitrile rubber parts should not be stored near these surroundings.
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Despite these, nitrile rubber is stabile in general temperature range : -40℉ to +225℉. Within this temperature range, after compounded nitrile rubber imparts good tensile strength, tear resistance, compression set as well as oil and fuel resistance.
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8 Y$ |9 z4 q# KThe nitrile type/class in ASTM D2000 or SAE J200 are BF,BG,BK and CH.
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Nitrile rubber is recommended to use in petroleum oils, fuel, silicone oils, silicone greases, ethylene glycol,water(below 212℉) and some non-polar chemical fluid or solvents. And it is not recommended to use in highly polar solvents (Acetone, MEK, benzene, toluene,xylene, etc.), aromatic brake fluid, strong acids and direct exposure to zone and sunlight.

现代吕布

为什么使用英文呢？？

foxalen

超實用的文章值得好好學習

xuxueli80514

顶起来,好资料............................

lifengming

不错，楼主能用英文写这些。在这个行业里英文这么好的不是很多噢，顶一下

凌云天

ding yi xia a !