Synthetic rubber nitrile

The original route to acrylonitrile was the catalytic reaction of HCN with acetylene. That was a combination of two compounds that together had all the characteristics youd like to avoid—poisonous, explosive, corrosive, and on and on. But during World War II, acrylonitrile became very important as a comonomer for synthetic rubber (nitrile rubber). Later, the growth for acrylonitrile came from synthetic fibers like Orion, Acrylon, and Dynel. 

Synthetic rubber nitrile Gloves made from nitrile are available in four different thicknesses as ambidextrous examination type, and in hand-specific styles, both lined and unlined. Heavier nitrile gloves are routinely used in manufacturing, cleaning, and the food-processing industry. 

Natural rubber Reclaimed rubber Synthetic rubbers Nitrile rubber... 

Nitrile Rubber. Nitrile mbbers are made by the emulsion copolymerization of acrylonitrile (9—50%) and butadiene (6) and designated NBR. The ratio of acrylonitrile (ACN) to butadiene has a direct effect on the properties on the nature of the polymers. As the ACN content increases, the oil resistance of the polymer increases (7). As the butadiene content increases, the low temperature properties of the polymer are improved (see Elastomers, SYNTHETIC-NITRILE RUBBER). 

The applications of polysulphide rubbers are due to their excellent oil and water resistance and their impermeability to gases. Because of other factors, including their unpleasant odour, particularly during processing, they are much less used than the two major oil-resistant synthetic rubbers, the polychloroprenes and the nitrile rubbers. 

The terms ebonite and hard rubber are now extended to cover hard produets made from synthetic rubbers. SBR is now replacing the natural materials in many ebonite applications whilst nitrile rubber ebonites are of interest where oil resistance is required. 

The name originally applied to all synthetic rubbers produced by the sodium polymerisation of butadiene it is derived from Bu for butadiene and Na for sodium. The name was subsequently used in various forms, e.g., Buna N for nitrile rubber or NBR, and Buna S for SBR. The tradename Perbunan (Bayer) is also derived from Buna. 

Also known as vulcanite and (mainly in the USA) hard rubber . The hard, horn-like product obtained when natural rubber and some synthetic rubbers such as nitrile (NBR) are vulcanised with a high proportion of sulphur or organic nonsulphur vulcanising agent. Butyl rubber and polysulphide rubber do not form ebonites. Ebullioscopy... 

A solvent for natural and most synthetic rubbers except nitrile. It is a petroleum spirit existing in five isomeric forms normal hexane has a boiling point of 69 °C. 

The rubber may be natural, in which case the latex is produced by the rubber tree. Latex of the main synthetic rubbers is produced by the technique of emulsion polymerisation. The term latex has been broadened in recent years and a general definition is now a stable dispersion of a polymeric substance in an aqueous medium . Latices may be classified as natural (from trees and plants), synthetic (by emulsion polymerisation) and artificial (by dispersion of the solid polymer in an aqueous medium). They may also be classified according to the chemical nature of the polymer, e.g., SBR, nitrile, polychloroprene, etc. 

A convenient term for any material possessing the properties of a rubber but produced from other than natural sources. A synthetic version of natural rubber has been available for many years with the same chemical formula, i.e., cis-1,4-polyisoprene, but it has not displaced the natural form. See also Butyl Rubber, Chloroprene Rubber, Ethylene-Propylene Rubber, Nitrile Rubber, Silicone Rubber and Styrene-Butadiene Rubber. 

Diene polymers refer to polymers synthesized from monomers that contain two carbon-carbon double bonds (i.e., diene monomers). Butadiene and isoprene are typical diene monomers (see Scheme 19.1). Butadiene monomers can link to each other in three ways to produce ds-1,4-polybutadiene, trans-l,4-polybutadi-ene and 1,2-polybutadiene, while isoprene monomers can link to each other in four ways. These dienes are the fundamental monomers which are used to synthesize most synthetic rubbers. Typical diene polymers include polyisoprene, polybutadiene and polychloroprene. Diene-based polymers usually refer to diene polymers as well as to those copolymers of which at least one monomer is a diene. They include various copolymers of diene monomers with other monomers, such as poly(butadiene-styrene) and nitrile butadiene rubbers. Except for natural polyisoprene, which is derived from the sap of the rubber tree, Hevea brasiliensis, all other diene-based polymers are prepared synthetically by polymerization methods. 

Butadienes two double bonds make it very reactive. It readily forms polymers, reacting with itself to form polybutadiene. Its also used as a comonomer to make styrene-butadiene rubber (SBR), polychloroprene, and nitrile rubber. These are all forms of synthetic rubber and account for about 75% of the butadiene consumed. The largest share of them is on highway vehicles—truck and car tires, hoses, gaskets, and seals. 

Fig. 14. Mastication of polystyrene — synthetic rubbers systems. Effect of the amount and type of rubber on dynamic flex resistance. 1 styrene rubber (SKS 30) 2 nitrile rubber (SKN 18) ...

Butadiene is used primarily in the production of synthetic rubbers, including styrene-butadiene rubber (SBR), polybutadiene nibber (BR), styrene-butadiene latex (SBL), chloroprene rubber (CR) and nitrile rubber (NR). Important plastics containing butadiene as a monomeric component are shock-resistant polystyrene, a two-phase system consisting of polystyrene and polybutadiene ABS polymers consisting of acrylonitrile, butadiene and styrene and a copolymer of methyl methacrylate, butadiene and styrene (MBS), which is used as a modifier for poly(vinyl chloride). It is also used as an intermediate in the production of chloroprene, adiponitrile and other basic petrochemicals. The worldwide use pattern for butadiene in 1981 was as follows (%) SBR + SBL, 56 BR, 22 CR, 6 NR, 4 ABS, 4 hexamethylenediamine, 4 other, 4. The use pattern for butadiene in the United States in 1995 was (%) SBR, 31 BR, 24 SBL, 13 CR, 4 ABS, 5 NR, 2 adiponitrile, 12 and other, 9 (Anon., 1996b). 

Synthetic rubber ebonites do not fundamentally differ from natural rubber ebonites in swelling behaviour. Synthetic rubbers combine more nearly completely with the added sulphur. Nitrile ebonites are outstanding in that they are almost unaffected even by solvents such as benzene carbon-disulphide which strongly swell natural, butadiene and styrene butadiene ebonites [4,5]. 

Natural rubber ebonites cannot be produced in brilliant colours which can be obtained with a number of synthetic rubbers like nitrile and resins such as high styrene. Ebonite products can be classified according to their primary uses as mentioned below. 

Emulsion polymers - [POLYMERS] (Vol 19) -acrylic elastomers [ELASTOMERS, SYNTHETIC - ACRYLICELASTOMERS] (Vol 8) -of acrylic monomers [ACRYLIC ESTER POLYMERS - SURVEY] (Vol 1) -of acrylonitrile [ACRYLONITRILE POLYMERS - SURVEY AND SAN (STYRENE-ACRYLONITRILECO-POLYMERS)] (Vol 1) -of methacrylic monomers [METHACRYLIC POLYMERS] (Vol 16) -nitrile rubber by [ELASTOMERS, SYNTHETIC - NITRILE RUBBER] (Vol 8) -of styrene/butadiene [STYRENE-BUTADIENERUBBER] (Vol 22) -synthetic rubber by [ELASTOMERS, SYNTHETIC - SURVEY] (Vol 8) -ofVDF [FLUORINECOMPOUNDS,ORGANIC-POLY(VINYLIDENE FLUORIDE)] (Volll) -for medical diagnostic reagents [MEDICAL DIAGNOSTIC REAGENTS] (Vol 16)... 

The most widely used synthetic rubber is styrene-butadiene rubber (SBR) (Fig. 1). Other commonly used elastomers are polybutadiene, polyethylene-propylene, butyl rubber, neoprene, nitrile rubbers, and polyisoprene. 

Synthetic elastomers, e.g. styrene-butadiene rubber, polychloroprene rubber, nitrile-butadiene rubber... 

The initial drive for acrylonitrile (AN) production (6.2 Mt/a in 2004 worldwide) was the discovery, in the late 1930s, of the synthetic rubber Buna N. Today nitrile rubbers represent only a minor outlet for AN which is utilized primarily for polymerization to give textile fibres (50%) and ABS resins (24%), and for dimerization to adiponitrile (10%). Early industrial processes depended on the addition of hydrogen cyanide to acetylene or to ethylene oxide, followed by the dehydration of intermediate ethylene cyanohydrin. Both processes are obsolete and are now supplanted by the ammoxidation of propylene (Equation 34) introduced in 1960 by Standard Oil of Indiana (Sohio). The reason for the success stems from the effectiveness of the catalyst and because propylene,... 

NOTE Ibtals for plastics are for those products listed and exclude some small-volume plastics. Synthetic rubber data include Canada. Dry-weight basis unless otherwise specified Density 0.940 and below " Data include Canada from 2001 Density above 0.940 Data include Canada from 1995 Data include Canada from 2000 Data include Canada from 1994 Includes styrene-butadiene copolymers and othm styrene-based polymers Unmodified Includes butyl styrene-butadiene rubber latex, nitrile latex, polyisoprene, and miscellaneous others. SOURCES American Plastics Council, International Institute of Synthetic Rubber Producers. 

Polyethylene and Polypropylene Acceptable bonds have been obtained between treated polyolefin surfaces with polar adhesives, such as epoxies, or solvent cements containing synthetic rubber or phenolic resin. The solvent adhesives are applied to both surfaces and the solvents allowed to evaporate before the parts are joined. Recommended epoxies are the anhydride-cured and amine-cured types. Also suitable is a two-component, polyamide-modified epoxy compound. Other adhesives that provide adequate bond strength to treated polyolefins include styrene-unsatmated polyester and solvent-type nitrile-phenolic (15). 

Butadiene is used as a chemical intermediate and as a polymer component in the synthetic rubber industry, the latter accounting for 75% of the butadiene produced. Styrene-butadiene rubber, polybutadiene rubber, adiponitrile, styrene-butadiene latex, acrylonitrile-butadiene-styrene resins, and nitrile rubber are used in the manufacture of tires, nylon products, plastic bottles and food wraps, molded rubber goods, latex adhesives, carpet backing and pads, shoe soles, and medical devices. 

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