Polybutadiene nitrile rubber

Butadiene is a monomer used in high volume in the manufacture of a wide range of polymers, including styrene-butadiene rubber, polybutadiene, nitrile rubber, acrylonitrile-butadiene-styrene resins and st rene-butadiene latexes. It is also an intermediate in the production of various other chemicals. 

Butadiene is a colorless, odorless, flammable gas, with a boiling point of -4.7°C and is used for the manufacture of polybutadiene, nitrile rubber, chloroprene, and various other polymers. An important synthetic elastomer is styrene-butadiene rubber (SBR) in the automobile tire industry. Specialty elastomers are polychloroprene and nitrile rubber, and an important plastic is acrylonitrile/butadiene/styrene (ABS) terpolymer. Butadiene is made into adiponitrile, which is converted into hexamethylenediamine (HMDA), one of the monomers for nylon. 

Figure 5.1.2. Dependence of equilibrium swelling of crosslinked elastomer of polyester urethane (1) and polybutadiene nitrile rubber (2) on the volume ftaction of acetone in the toluene-acetone mixture. [Adapted, by permission, from V.V. Tereshatov, V.Yu. Senichev,...

Figure 2.37. Dependence of Wq on for a system formed by polybutadiene-nitrile rubber ("SKN-26 ) tetramethylene-dimetacrylate during curing at 80°C, the concentration of initiator PDK is 0,5% and oligomer content is 70 (1), 60 (2), 50 (3) and 30% (4). Synthesis of samples 1-3 - from joint solutions, 4 -from solutions (I) and through swelling (II).

In general, carbon black, clay, calcium carbonate and talc are the most common fillers added to rubbers. Some rubbers are less demanding of fillers (e.g. nitrile rubber, butyl rubber, polybutadienes) than others. 

Polymers can be modified by the introduction of ionic groups [I]. The ionic polymers, also called ionomers, offer great potential in a variety of applications. Ionic rubbers are mostly prepared by metal ion neutralization of acid functionalized rubbers, such as carboxylated styrene-butadiene rubber, carboxylated polybutadiene rubber, and carboxylated nitrile rubber 12-5]. Ionic rubbers under ambient conditions show moderate to high tensile and tear strength and high elongation. The ionic crosslinks are thermolabile and, thus, the materials can be processed just as thermoplastics are processed [6]. 

Natural rubber Styrene-butadiene rubber Polybutadiene Polyisoprene Nitrile rubber Halogenated nitrile rubber Ethylene-propylene rubber EPDM... 

The production of polymers by emulsion polymerization has been important since at least World War II. For example, the production of SBR, polybutadiene, and nitrile rubbers was 1.2 million metric tons in 1986 in the U. S. alone (1). Emulsion copolymers are becoming increasingly important from an industrial viewpoint because their unique mix of properties over homopolymers can open up new market opportunities. A review of the qualitative and quantitative aspects of emulsion polymerization can be found in reviews by Min and Ray (2) and more recently by Penlidis et al. (2), and Gilbert and Napper (A). 

A gas, CH2CHCHCH2 (buta-1,3-diene), used in the manufacture of polybutadiene rubber and as one of the copolymers in the manufacture of styrene-butadiene and nitrile rubbers. 

Copolymers of styrene, especially with acrylonitrile, also attained increasing importance both in the unmodified form (30) and modified with rubber as ABS copolymers. The first products of this kind were blends of nitrile rubber and SAN (31). However, these only had mediocre mechanical properties because the interfacial compatibility was insufficient. The breakthrough came when nitrile rubber was replaced by a polybutadiene rubber which was grafted in emulsion with styrene and acrylonitrile... 

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. 

Berlin and coworkers (5,56) desired to obtain a material with an increased mechanical strength. They carried out a plasticization of bulk ami emulsion polystyrene molecular weight 80000 and 200000 respectively at 150-160° C, with polyisobutylene, butyl rubber, polychloroprene, polybutadiene, styrene rubber (SKS-30) and nitrile rubber (SKN 18 and SKN 40). The best results were obtained with the blends polystyrene-styrene rubber and polystyrene-nitrile rubber. An increase of rubber content above 20-25% was not useful, as the strength properties were lowered. An increase in the content of the polar comonomer, acrylonitrile, prevents the reaction with polystyrene and decreases the probability of macroradical combination. This feature lowers the strength, see Fig. 14. It was also observed that certain dyes acts as macroradical acceptors, due to the mobile atoms of hydrogen of halogens in the dye, AX ... 

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). 

Polymerization Reactions. The polymerization of butadiene with itself and with other monomers represents its largest commercial use. The commercially most important polymers are styrene—butadiene rubber (SBR), polybutadiene (BR), styrene—butadiene latex (SBL), acrylonitrile—butadiene—styrene polymer (ABS), and nitrile rubber (NR). The reaction mechanisms are free-radical, anionic, cationic, or coordinate, depending on the nature of the initiators or catalysts (194—196). 

Elastomers, synthetic -acrylic elastomers [ELASTOMERS, SYNTHETIC - ACRYLIC ELASTOMERS] (Vol 8) -butyl rubber [ELASTOMERS, SYNTHETIC - BUTYL RUBBER] (Vol 8) -chlorosulfonated polyethylene [ELASTOMERS, SYNTHETIC - CHLOROSULFONATED POLYETHYLENE] (Vol 8) -ethylene-acrylic elastomers [ELASTOMERS, SYNTHETIC - ETHYLENE-ACRYLIC ELASTOMERS] (Vol 8) -ethylene-propylene-diene rubber [ELASTOMERS,SYNTHETTC - ETHYLENE-PROPYLENE-DIENE RUBBER] (Vol 8) -fluorocarbon elastomers [ELASTOMERS, SYNTHETIC - FLUOROCARBON ELASTOMERS] (Vol 8) -nitrile rubber [ELASTOMERS, SYNTHETIC - NITRILE RUBBER] (Vol 8) -phosphazenes [ELASTOMERS, SYNTHETIC - PHOSPHAZENES] (Vol 8) -polybutadiene [ELASTOMERS, SYNTHETIC - POLYBUTADIENE] (Vol 8) -polychloroprene [ELASTOMERS, SYNTHETIC - POLYCHLOROPRENE] (Vol 8) -polyethers (ELASTOMERS, SYNTHETIC - POLYETHERS] (Vol 8) -polyisoprene [ELASTOMERSSYNTHETTC - POLYISOPRENE] (Vol 9) -survey [ELASTOMERS, SYNTHETIC - SURVEY] (Vol 8)... 

Most ABS is made by emulsion polymerization. A polybutadiene or nitrile rubber latex is prepared, and styrene plus acrylonitrile are grafted upon the elastomer in emulsion. The effect of rubber particle size in ABS graft copolymer on physical properties is the subject Chapter 22 by C. F. Parsons and E. L. Suck. Methyl methacrylate was substituted for acrylonitrile in ABS by R. D. Deanin and co-workers. They found a better thermoprocessability, lighter color, and better ultraviolet light stability. 

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. 

Wettability of Elastomers and Copolymers. The wettability of elastomers (37, 38) in terms of critical surface tension was reported previously. The elastomers commonly used for the reinforcement of brittle polymers are polybutadiene, styrene-butadiene random and block copolymers, and butadiene-acrylonitrile rubber. Critical surface tensions for several typical elastomers are 31 dyne/cm. for "Diene rubber, 33 dyne/cm. for both GR-S1006 rubber and styrene-butadiene block copolymer (25 75) and 37 dyne/cm. for butadiene-acrylonitrile rubber, ( Paracril BJLT nitrile rubber). The copolymerization of butadiene with a relatively polar monomer—e.g., styrene or acrylonitrile—generally results in an increase in critical surface tension. The increase in polarity is also reflected in the increase in the solubility parameter (34,39, 40) and in the increase of glass temperature (40). We also noted a similar increase in critical surface tensions of styrene-acrylonitrile copolymers with the... 

Of the 17 billion lb of butadiene consumed in 1999, almost two thirds went into the production of elastomers (styrene-butadiene latex rubber (SBR), polybutadiene, nitrile, and polychloroprene). Adiponitrile, ABS resins, styrene-butadiene latex, styrene block copolymers, and other smaller polymer uses accounted for the remainder. The largest single use was for styrene-butadiene copolymers (SBR and latex). Most of it was made by an emulsion process using a free-radical initiator and a styrene-butadiene ratio of about 1 3. More detailed description of the rubber and polymer used can be found in Chapters 16 and 15. 

Impact Properties. Chemical Nature of the Rubber. If the rubber is too compatible with the matrix, it will dissolve in the rigid material and disperse on a molecular scale. Little or no reinforcement will occur since the rubber particles become smaller than the radius of the tip of a stress-induced propagating crack. However if it is highly incompatible, good adhesion between rubber and matrix cannot be obtained. For example polybutadiene rubber adheres poorly to a styrene/acrylonitrile copolymer, but a nitrile rubber adheres well to the SAN copolymer. If grafting techniques are used however, compatibility is less of a problem since the rubber is chemically bonded to the matrix. 

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. 

Recently, nanocomposites were prepared with different grades of nitrile rubber with acrylonitrile contents of 19%, 34%i, and 50%i, with SBR (23%i styrene content), and with polybutadiene rubber with Na-montmorillonite clay. The clay was modified with... 

The main types of rubber used in the field of anti-corrosion are natural rubber, polyisoprene, polybutadiene, polyurethane, butyl rubber, styrene butadiene, nitrile rubber, ethylene propylene rubber, polychloroprene, silicone rubber, and vinylidene rubber. The wide ranges of available natural and synthetic rubbers offer a versatility of properties to suit almost every corrosive condition encountered in the process industries. 

Nitrile rubber Polybutadiene-co- acrylonitrile Sulfur Poor Poor... 

Buna 85 is polybutadiene (the number represents Mooney viscosity), molecular weight -80,000. Hard rubber has high softening point and excellent chemical resistance. The coefficient of vulcanisation to the ebonite stage is 39.3. The coefficient of vulcanisation is the number of unit weight of sulfur combined with 100 units by weight of unsaturated hydrocarbons. Buna S is a butadiene styrene copolymer with 70/30 to 68/32 ratio. Buna SS contains a high proportion of styrene. Perbunan are nitrile rubbers... 

The carboxylation of EPR is summarized in Table VI, while the carboxylations of ABS, nitrile rubber, and ds-l,4-polybutadiene are shown in Table VII. 

The catalyzed graft copolymerization of styrene-methyl methacry-late-EASC and a-methylstyrene-methacrylonitrile-EASC onto nitrile rubber in solution is shown in Table XII. In addition, grafting has been done on ethylene-propylene copolymers, polybutadiene, acrylic ester copolymers, and other polymers containing labile hydrogen atoms. 

Commercially important elastomeric thermoplastic alloys are dynamically vulcanized blends of polypropylene with high volume fractions of EPDM, polybutadiene rubber, nitrile rubber, and butyl rubber (Santoprene , Vyram , Geolast and Trefsin ) all currently sold by Advanced Elastomer Systems, a joint venture of Monsanto and Exxon. Another recent member of the commercial dynamically cured elastomeric thermoplastic alloys is the blend of PVC and a crosslinked ethylene copolymer (Alcryn , DuPont). The current consumption of all the elastomeric thermoplastic alloys in the USA is over 23 kton/y, with the EPDM/PP blend (Santoprene ) assuming about 90% of the market share. 

ABS resins are produced primarily by grafting styrene and acrylonitrile onto polybutadiene latex in a batch or continuous polymerization process. They may also be made by blending emulsion latexes of styrene-acrylonitrile (SAN) and nitrile rubber (NBR). 

The reaction of the pyrolysis vapors with mercury(II) oxide will differentiate between these materials. To do this, heat a dry sample of the plastic in the pyrolysis tube closed with a piece of prepared filter paper. To prepare the paper, drench it with a solution of 0.5 g yellow mercury(ll) oxide in sulfuric acid (1.5 ml concentrated sulfuric acid added to 8 ml water, carefully). If the vapor gives a golden yellow spot, this indicates polyisobutylene, butyl rubber, and polypropylene (the latter only after a few minutes). Polyethylene does not react. Natural and nitrile rubber as well as polybutadiene yield a brown spot Waxlike greases are the products in the pyrolysis of polyethylene and polypropylene. Polyethylene smells like paraffin, and polypropylene is slightly aromatic. 

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