Styrene butadiene vinylpyridine

Pyridine bases namely 2 4-picolines are important commodity chemicals which are used in pharmaceuticals, rubber eind agricultural industries. 2-picoline is consumed for several different pesticides, and is used in the production of 2-vinylpyridine, which is a component of styrene-butadiene-vinylpyridine terpolymer latexes. The major outlet for 4-picoline is for the manufacture of 4-vinylpyridine and INH an anti-tubercular drug. The stringent specifications laid down for these products in pharmaceutical and agricultural applications can not be met from natural sources namely from coal carbonisation byproducts. Synthetic pyridine is the only answer to this problem. 

An RFL dip consists of an aqueous resorcinol formaldehyde resin liquid with a ruhher latex. The RF resin is used to achieve good adhesion to the organic fiber substrate whether it be rayon, nylon, or polyester. The rubber latex portion can be a natural rubber latex or a styrene butadiene vinylpyridine (terpolymer) latex or even a neoprene latex. This rubber latex is present to achieve good adhesion with the rubber matrix itself. So the RFL allows good adhesion between the rubber and the textile cord reinforcement whether it is used in the manufacture of passenger tires, truck tires, off-the-road tires, power transmission belts, V-belts, timing belts, or various hose products. 

Styrene butadiene vinylpyridine latex (SBVPL) is the most popular rubber latex used to make RFL dips to achieve good rubber-to-fabric adhesion. Usually SBVPL is used for good adhesion between textile cord and rubber compounds based on general-purpose elastomers (NR, SBR, and BR). Occasionally other latexes besides SBVPL are used as well. For example, sometimes natural rubber latex is used for an RFL dip. Then again, neoprene latex can also be used, especially if the rubber compound is based on neoprene. The purpose of the rubber latex component of the RFL is to promote adhesion with the rubber matrix of the product. 

Figure 5.24 Polymerization of Styrene butadiene vinylpyridine latex, SBVPL Synonyms...

Styrene butadiene vinylpyridine latex Feedstock Dependency... 

Styrene butadiene vinylpyridine latex is used in the rubber industry because it imparts very good adhesion with the general-purpose diene elastomers used in many rubber compounds. Other rubber latexes may not do as well in imparting good adhesion to cured general-purpose rubber-based compounds. 

Tire Cord. Melamine resins are also used to improve the adhesion of mbber to reinforcing cord in tires. Textile cord is normally coated with a latex dip solution composed of a vinylpyridine—styrene—butadiene latex mbber containing resorcinol—formaldehyde resin.. The dip coat is cured prior to use. The dip coat improves the adhesion of the textile cord to mbber. Further improvement in adhesion is provided by adding resorcinol and hexa(methoxymethyl) melamine [3089-11 -0] (HMMM) to the mbber compound which is in contact with the textile cord. The HMMM resin and resorcinol cross-link during mbber vulcanization and cure to form an interpenetrating polymer within the mbber matrix which strengthens or reinforces the mbber and increases adhesion to the textile cord. Brass-coated steel cord is also widely used in tires for reinforcement. Steel belts and bead wire are common apphcations. Again, HMMM resins and resorcinol [108-46-3] are used in the mbber compound which is in contact with the steel cord to reinforce the mbber and increase the adhesion of the mbber to the steel cord. This use of melamine resins is described in the patent Hterature (49). 

Synthetic. The main types of elastomeric polymers commercially available in latex form from emulsion polymerization are butadiene—styrene, butadiene—acrylonitrile, and chloroprene (neoprene). There are also a number of specialty latices that contain polymers that are basically variations of the above polymers, eg, those to which a third monomer has been added to provide a polymer that performs a specific function. The most important of these are products that contain either a basic, eg, vinylpyridine, or an acidic monomer, eg, methacrylic acid. These latices are specifically designed for tire cord solutioning, papercoating, and carpet back-sizing. 

P(S VPD) P(S-b-BR) PSA PSBMA poly(styrene-co-4-vinylpyridine) styrene-butadiene rubber block copolymer poly(sodium acrylate) poly(sec-butyl methacrylate)... 

It is claimed that styrene/butadiene diblock polymers bring about an improvement in the hardness, strength, and processability of polybutadiene elastomers (27), as well as an improvement in the ozone resistance of neoprene rubber (28). Styrene diblock polymers have also been made with isoprene, a-methyIstyrene, methyl methacrylate, vinylpyridine, and a-olefins. Block copolymers of ethylene, propylene, and other a-olefins with each other have been made as well. Heteroatom block copolymers based on styrene or other hydrocarbons and alkylene oxides, phenylene oxides, lactones, amides, imides, sulfides, or slloxanes have been prepared. 

L. Liang and S. Ying, Charge-mosaic membrane from gamma-irradiated poly(styrene-butadiene-4-vinylpyridine) triblock copolymer, J. Polym. Sci., Polym. Phys., 1993, 31, 1075-1081. 

Monomers styrenes, butadiene, isoprene, vinylpyridines, methacrylates, ethylene... 

The methyl group of a-picoline reacts, by virtue of its C-H acidity, with formaldehyde to form 2-pyridyl ethanol, which gives 2-vinylpyridine in the presence of bases. Vinylpyridine serves as a co-monomer in the production of modified styrene-butadiene rubber and special polyacrylic fibers to improve dye absorption. 

Soum and Fontanille report that di-s-butyl magnesium generates living polymer from 2-vinylpyridine without the involvement of the side-reactions that afflict the polymerization initiated by alkali metal alkyls the resulting polymer has an isotacticity index of 0.9. Arai et al. have synthesized styrene-butadiene-4-vinylpyridine triblock copolymers. Hogen-Esch et a/. have continued their study of the stereochemistry of the anionic polymerization of 2-vinylpyridine in THF solution. Oligomers were synthesized by addition of alkali salts of 2-ethylpyridine to 2-vinylpyridine termination was effected by reaction with methyl iodide. Highly isotactic products were obtained with U and Na as counterions but with K or Rb there was no stereoselection. Epimerization resulted in the expected statistical mixtures of stereoisomers and it was concluded that stereoselection is kinetically controlled. 

Methyl-5-vinylpyiidine-butadiene copolymers (usually about 20 80 molar) are now commercially available. These copolymers are compounded and vulcanized in much the same way as styrene-butadiene copolymers and the vulcanizates have broadly similar properties the vinylpyridine rubbers show improved low temperature flexibility, abrasion resistance and oil resistance. 

Monomers Several general categories of vinyl monomers are suitable for anionic polymerizations. These include aromatic monomers (2-vinylpyridine, styrene), conjugated dienes (butadiene, isoprene), and alkyl methacrylates. In the case of vinyl monomers, adjacent substituents that stabilize an anion are most suitable for anionic polymerizations. Examples include substituents found in styrene, butadiene, isoprene, alkyl methacrylates, or cyano acrylate which stabilize propagating anions by electronic effects. 

Since this time, latices of vinylpyridine-styrene-butadiene terpolymers have found limited use in the treatment of textile fibres (such as tyre cords) to give improved adhesion to rubber. In this application, various vinylpyridines have been utilized but 2-vinylpyridine is the most commonly used. The vinyl-pyridine-styrene-butadiene weight ratio is typically 15 15 70. 

AlkyUithium compounds are primarily used as initiators for polymerizations of styrenes and dienes (52). These initiators are too reactive for alkyl methacrylates and vinylpyridines. / -ButyUithium [109-72-8] is used commercially to initiate anionic homopolymerization and copolymerization of butadiene, isoprene, and styrene with linear and branched stmctures. Because of the high degree of association (hexameric), -butyIUthium-initiated polymerizations are often effected at elevated temperatures (>50° C) to increase the rate of initiation relative to propagation and thus to obtain polymers with narrower molecular weight distributions (53). Hydrocarbon solutions of this initiator are quite stable at room temperature for extended periods of time the rate of decomposition per month is 0.06% at 20°C (39). 

Vinylpyridine (23) came into prominence around 1950 as a component of latex. Butadiene and styrene monomers were used with (23) to make a terpolymer that bonded fabric cords to the mbber matrix of automobile tires (25). More recendy, the abiUty of (23) to act as a Michael acceptor has been exploited in a synthesis of 4-dimethylaminopyridine (DMAP) (24) (26). The sequence consists of a Michael addition of (23) to 4-cyanopyridine (15), replacement of the 4-cyano substituent by dimethylamine (taking advantage of the activation of the cyano group by quatemization of the pyridine ring), and base-cataly2ed dequatemization (retro Michael addition). 4-r)imethyl aminopyri dine is one of the most effective acylation catalysts known (27). 

The most common adhesive system used for bonding continuous fibers and fabrics to rubber is resorcinol-formaldehyde latex (RFL) system. In general, RFL system is a water-based material. Different lattices including nitrile and SBR are used as the latex for the adhesive system. 2-Vinylpyridine-butadiene-styrene is the common latex used in the adhesive recipe. RFL system is widely being used in tires, diaphragms, power transmission belts, hoses, and conveyor belts because of its dynamic properties, adhesion, heat resistance, and the capacity to bond a wide range of fabrics and mbbers. 

List C contains peroxidisable monomers, where the presence of peroxide may initiate exothermic polymerisation of the bulk of material. Precautions and procedures for storage and use of monomers with or without the presence of inhibitors are discussed in detail. Examples cited are acrylic acid, acrylonitrile, butadiene, 2-chlorobutadiene, chlorotrifluoroethylene, methyl methacrylate, styrene, tetraflu-oroethylene, vinyl acetate, vinylacetylene, vinyl chloride, vinylidene chloride and vinylpyridine [1]. 

Penultimate effects have been observed for many comonomer pairs. Among these are the radical copolymerizations of styrene-fumaronitrile, styrene-diethyl fumarate, ethyl methacrylate-styrene, methyl methacrylate l-vinylpyridine, methyl acrylate-1,3-butadiene, methyl methacrylate-methyl acrylate, styrene-dimethyl itaconate, hexafluoroisobutylene-vinyl acetate, 2,4-dicyano-l-butene-isoprene, and other comonomer pairs [Barb, 1953 Brown and Fujimori, 1987 Buback et al., 2001 Burke et al., 1994a,b, 1995 Cowie et al., 1990 Davis et al., 1990 Fordyce and Ham, 1951 Fukuda et al., 2002 Guyot and Guillot, 1967 Hecht and Ojha, 1969 Hill et al., 1982, 1985 Ma et al., 2001 Motoc et al., 1978 Natansohn et al., 1978 Prementine and Tirrell, 1987 Rounsefell and Pittman, 1979 Van Der Meer et al., 1979 Wu et al., 1990 Yee et al., 2001 Zetterlund et al., 2002]. Although ionic copolymerizations have not been as extensively studied, penultimate effects have been found in some cases. Thus in the anionic polymerization of styrene t-vinylpyri-dine, 4-vinylpyridine adds faster to chains ending in 4-vinylpyridine if the penultimate unit is styrene [Lee et al., 1963]. 

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