Copolymers of butadiene

C22H30 1 -[ 1 -(But-2-enyl)hex-4-enyl]-4-(cyclohex-3-enyl)benzene F-b2G 

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The mbber latex is usually produced in batch reactors. The mbber can be polybutadiene [9003-17-2] or a copolymer of 1,3-butadiene [106-99-0] and either acrylonitrile [107-13-1] or styrene [100-42-5]. The latex normally has a polymer content of approximately 30 to 50% most of the remainder is water. 

Styrene—Butadiene Rubber (SBR). This is the most important synthetic mbber and represents more than half of all synthetic mbber production (Table 3) (see Styrene-butadiene rubber). It is a copolymer of 1,3-butadiene, CH2=CH—CH=CH2, and styrene, CgH5CH=CH2, and is a descendant of the original Buna S first produced in Germany during the 1930s. The polymerization is carried out in an emulsion system where a mixture of the two monomers is mixed with a soap solution containing the necessary catalysts (initiators). The final product is an emulsion of the copolymer, ie, a fluid latex (see Latex technology). 

Synthetic rubber is any vulcanlsable rubber like polymer, which is capable of getting stretched to twice its length. However, it returns to its original shape and size as soon as the external stretching force is released. Thus, synthetic mbbers are either ho mo polymers of 1,3- butadiene derivatives or copolymers of 1, 3 - butadiene or its derivatives with another unsaturated monomer. 

Buna-N Is a copol5mier of 1,3-butadIene and aciylonitrile and Buna-S is a copolymer of 1,3-butadIene and styrene. 

Copolymerisation is a process in which a mixture of more than one monomeric species is allowed to polymerise. The copolymer contains multiple units of each monomer in the chain. The examples are copolymers of 1,3-butadiene and st3rrene and 1, 3-butadiene and acrylonitrile. 

Nitrile rubber (NBR), a copolymer of 1,3-butadiene with 20-40% acrylonitrile, is noted for its oil resistance. More than 150 million pounds are produced annually in the United States. Applications include fuel tanks, gasoline hoses, and creamery equipment. Nitrile resin is made by copolymerizing acrylonitrile with about 20-30% styrene or methyl methacrylate in the presence of NBR or SBR rubber to yield a blend of the graft terpolymer and homocopolymer. Applications include extruded and blow-molded containers for household, automotive, and other products as well as some nonbeverage foods (spices, vitamins, candy). 

Natta, Porri, Carbonaro and Lugli (25) have prepared copolymers of 1,3-butadiene with 1,3-pentadiene in the whole range of compositions. The properties of the copolymers, in which all butadiene and pentadiene comonomer units are in the trans-1,4 configuration, clearly show the isomorphous replacement between the two types of units. The melting point/composition data show that the copolymer melting temperatures are a regular function of composition and are always comprised between those of trans-1,4-polybutadiene modification II and trans-1,4-polypentadiene. Also the X-ray diffraction spectra of the copolymers show that the trans-1,4-pentadiene units are isomorphous with the trans-1,4-butadiene units crystallized in the crystalline modification of the latter stable at high temperatures (form II). 

Natta, G., L. Porri, A. Carbonaro, and G. Lugli Phenomena of isomorphism and polymorphism in trans-1,4-copolymers of 1,3-butadiene with 1,3-pen-tadiene. Makromol. Chem. 53, 52 (1962). 

Other binders are polyvinylchloride 112, 128), sometimes with a plasticizer 56) polyvinylacetal, specifically polyvinylformal plasticised with a copolymer of 1 3-butadiene and acrylonitrile (70) fluoro carbon polymers for preference a chlorotrifluoro ethylene polymer 132). 

This is the most important general purpose of synthetic rubber and represents more than half of all synthetic rubber production. It is a copolymer of 1,3-butadiene and styrene, and is a descendent of the original Bunas first produced in Germany during the 1930s [2]. 

Copolymers of 1,3-butadiene and styrene (SBR) are elastomers of great technical importance that are used for automobile tires [465-474]. In addition to a free-radical process, they can be made by anionic initiation with alkyllithium compounds. In polar solvents the reaction rate of styrene anions with 1,3-butadiene is greater than with styrene, whereas in polar solvents this is just the other way around. The copolymerization parameter rj for styrene-butadiene is 0.03 in hexane and 8 in THF r2 is calculated as 12.5 in hexane and 0.2 in THF [465]. Therefore, a strong dependence of the styrene content of the polymers on the degree of conversion is observed in discontinuous polymerizations. 

By using rare earth metals or radicals it is possible to copolymerize 1,3-butadiene and other dienes with cis-, A linkage [3,498]. Polymers of 1,3-butadiene and isoprene at any ratio can be obtained. Copolymes of 1,3-butadiene and 1,3-pentadiene can be produced with catalysts on the basis of vanadium chelates. 1,3-Butadiene is almost completely converted to trans-, A units, whereas 1,3-pentadiene yields 50 to 60% 1,4-addition and 40 to 50% 1,2-addition products. At a 1,3-pentadiene content of 26 to 45wt%, the copolymers are amorphous, featuring high rigidity [499-501]. Diethylaluminum chloride, nickel naphthenate, and water catalyze the copolymerization of 1,3-butadiene and acetylene. The low-molecular-weight copolymers contain mostly cis-Q-Q double bonds [502]. 

Alternating copolymers of 1,3-butadiene with ethene, propene, acrylonitrile, isobutene, and 2-methylacrylic acid methyl ester are known [503-513]. Suitable catalysts are titanium and vanadium compounds. The stereoregularity of the butadiene units is... 

Statistical copolymers of 1,3-butadiene and ethene are obtained with bis(cyclopen-tadienyl)zirconium dichloride and aluminoxane. The copolymers contain up to 13% trans-1,4 bonded butadiene [515]. 1,3-Butadiene forms alternating copolymers with acrylonitrile and esters of acrylic acid when the latter is complexed by strong Lewis acids (e.g., alkylaluminum halogenides and zinc chloride) [516,517]. Selective hydrogenation of the double bond yields nitrile rubbers with a low swelling capacity. 

It is possible to synthesize copolymers of 1,3-butadiene and isoprene by using a MeCpTiF3/MAO catalyst. The copolymer has a glass transition temperature of —60°C. 

Nitrile rubbers are broadly defined as copolymers of a diene and a vinyl unsaturated nitrile. This chapter will focus primarily on emulsion-polymerized copolymers of 1,3-butadiene and acrylonitrile, which represent the bulk of the commercially available nitrile elastomers. Commercial nitrile rubbers contain between 15 and 50% acrylonitrile, and have the following general structure ... 

Give abbreviated stmctnres of each of the following compounds (a) ( )-l,4-poly-2-methyl-l,3-butadiene [(i )-l,4-poly-isoprene] (b) l,2-poly-2-methyl-l,3-butadiene (1,2-polyiso-prene) (c) 3,4-poly-2-methyl-l,3-butadiene (3,4-polyisoprene) (d) copolymer of 1,3-butadiene and ethenylbenzene (styrene, QH5CH=CH2, SBR, used in automobile tires) (e) copolymer of 1,3-butadiene and propenenitrile (acrylonitrile, CH2=CHCN, latex) (f) copolymer of 2-methyl-1,3-butadiene (isoprene) and 2-methylpropene (butyl rubber, for inner tubes). 

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