Butadiene polymers and copolymers

Polybutadienes and polychloroprene, as well as styrene-butadiene, butadiene-acrylonitrile, and dehydrated poly (vinyl 

Grafting anionically prepared polybutadiene with MA, in a 4 1 weight ratio, at 200°Cgave copolymer with 16% grafted anhydride. Ammonolysis gave a water-soluble amide-ammonium salt useful in waterborne coatings. 

The product was also useful for producing hard, flexible, adherent wire coatings. 

Photoreactions of MA with 1,2-polybutadiene, 1,4-polybutadiene, poly(styrene-co-butadiene), poly(styrene-co-isoprene), polystyrene, and poly(styrene-co-methyl methacrylate) have been studied in air. In homogeneous solutions, MA addition to the polymers proceeds efficiently by a chain mechanism, where the quantum yield of the photoaddition was greater than unity under irradiation at A 310 nm. From the effects of solvent and photosensitizers and spectroscopic data, a radical chain mechanism was proposed to account for addition and crosslinking of the polymers by MA molecules. The photoaddition reaction was applied to the surface of polymer films. The photoreactions were conducted at the interphase between solid polymer and acetone solution of anhydride and also at the interphase between solid polymer and gaseous anhydride. Irradiation with a 300-W high-pressure lamp brought about considerable surface modification, as shown by wettability and dyeability properties. 

Mastication of polychloroprene with MA and MA-styrene or MA-vinyl acetate mixtures gives carboxylated chloroprene rubbers/ The extent of the mechanochemical grafting of the base polymer with anhydride is increased 3-4 times in the presence of the vinyl monomers. The results are akin to the case where styrene improves grafting of MA on polybutadiene. Ivan et have recently reported techniques for grafting MA on cyclopenta-dienylated polychloroprene. 

Butadiene could be polymerized using free radical initiators or ionic or coordination catalysts. When butadiene is polymerized in emulsion using a free radical initiator such as cumene hydroperoxide, a random polymer is obtained with three isomeric configurations, the 1,4-addition configuration dominating  

Polymerization of butadiene using anionic initiators (alkyllithium) in a nonpolar solvent produces a polymer with a high cis configuration. A high cis-polybutadiene is also obtained when coordination catalysts are used. 

Styrene-butadiene rubber (SBR) is the most widely used synthetic rubber. It can be produced by the copolymerization of butadiene (= 75%) and styrene (=25%) using free radical initiators. A random copolymer is obtained. The micro structure of the polymer is 60-68% trans, 14-19% cis, and 17-21% 1,2-. Wet methods are normally used to characterize polybutadiene polymers and copolymers. Solid state NMR provides a more convenient way to determine the polymer micro structure.  

Currently, more SBR is produced by copolymerizing the two monomers with anionic or coordination catalysts. The formed copolymer has better mechanical properties and a narrower molecular weight distribution. A random copolymer with ordered sequence can also be made in solution using butyllithium, provided that the two monomers are charged slowly. Block copolymers of butadiene and styrene may be produced in solution using coordination or anionic catalysts. Butadiene polymerizes first until it is consumed, then styrene starts to polymerize. SBR produced by coordinaton catalysts has better tensile strength than that produced by free radical initiators. 

The main use of SBR is for tire production. Other uses include footwear, coatings, carpet backing, and adhesives. 

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In more recent work on hydrogenation of butadiene polymers and copolymers, the attempt was made to explain the dependence on hydrogen pressure with sole rate control by olefin addition to H2RhClPh2 (X3) and quasi-equilibrium rhodium distribution over the complexes with and without hydrogen [59] instead of kinetic significance of the step Xq + H2 — X3. This gives a rate equation for double-bond disappearance of the form... 

COO Cooper, W., Vaughan, G., Eaves, D.E., and Madden, R.W., Molecnlar weight distribution and branching in butadiene polymers and copolymers, J. Polym. Sci., 50, 159, 1961. 

Butadiene polymers and copolymers have been treated with (see... 

Glass-fiber filled laminates Butadiene polymers and copolymers Poland 98,524 1979 Politechvika Wroclawska... 

The most common VI improvers are methacrylate polymers and copolymers, acrylate polymers (see Acrylic ester polymers), olefin polymers and copolymers, and styrene—butadiene copolymers. The degree of VI improvement from these materials is a function of the molecular weight distribution of the polymer. VI improvers are used in engine oils, automatic transmission fluids, multipurpose tractor fluids, hydrautic fluids, and gear lubricants. Their use permits the formulation of products that provide satisfactory lubrication over a much wider temperature range than is possible using mineral oils alone. 

Fig. 8. Thermogravimetric analysis of polymers and copolymers of styrene in nitrogen at 10°C/min A represents PS B, poly(vinyltoluene) C, poly(a-methylstyrene) D, poly(styrene-i (9-acrylonitrile), with 71.5% styrene E, poly(styrene-i (9-butadiene), with 80% styrene and F,...

The hydrogenation of unsaturated polymers and copolymers in the presence of a catalyst offers a potentially useful method for improving and optimizing the mechanical and chemical resistance properties of diene type polymers and copolymers. Several studies have been published describing results of physical and chemical testing of saturated diene polymers such as polybutadiene and nitrile-butadiene rubber (1-5). These reports indicate that one of the ways to overcome the weaknesses of diene polymers, especially nitrile-butadiene rubber vulcanizate, is by the hydrogenation of carbon-carbon double bonds without the transformation of other functional unsaturation such as nitrile or styrene. 

There are various requirements for impact-modified PVC. The most demanding is for outdoor sidings and window frames, where lifetimes of 20 years are expected. Because butadiene polymers or copolymers (e.g., acrylonitrile/butadiene/styrene (ABS), methyl methacrylate/butadiene/styrene (MBS)) are susceptible to UV degradation these polymers are usually not employed instead acrylate polymers are used for these applications. 

Butadiene and isoprene have two double bonds, and they polymerize to polymers with one double bond per monomeric unit. Hence, these polymers have a high degree of unsaturation. Natural rubber is a linear cis-polyisoprene from 1,4-addition. The corresponding trans structure is that of gutta-percha. Synthetic polybutadienes and polyisoprenes and their copolymers usually contain numerous short-chain side branches, resulting from 1,2-additions during the polymerization. Polymers and copolymers of butadiene and isoprene as well as copolymers of butadiene with styrene (GR-S or Buna-S) and copolymers of butadiene with acrylonitrile (GR-N, Buna-N or Perbunan) have been found to cross-link under irradiation. 

The polymer was then dried in an oven at 40°C and 60-70 mm pressure. Purified butadiene polymers and butadiene-styrene copolymers were analyzed by infrared and nmr spectroscopy(4,5,6). 

In contrast to the polymers and copolymers of butadiene, the oligomers of aromatic olefins, like styrene, are not compatible with PVC. Oligomers of alkylated polystyrenes are a little better, especially in combination with other liquid plasticizers. Copolymers of styrene and isobutylene are not suitable for use with PVC. 

Polyco [Borden], TM for a series of thermoplastic polymers in the form of water emulsions or solvent solutions, applied to vinyl acetate polymers and copolymers, butadiene-styrene copolymer lat-ics, polystyrenes, vinyl and vinylidene chloride copolymers, acrylic copolymers, and water-soluble polyacrylates. 

Figure 6. Variations of tensile strength as a function of composition of butadiene (BU) and styrene (ST)polymers and copolymers. Key A, polystyrene homopolymer B, 52/48 BU/ ST block copolymer C, 70/30 BU/ ST block copolymer D, 75/25 BU/ ST block copolymer E, 75/25 BU/ ST random copolymer F, butadiene homopolymer.

Figure 3, Effects of ozone exposure on critical surface energy of butadiene (BUj and styrene (ST) polymers and copolymers. Exposure curve units are ppm-min. Key , 75/25 BU/ST block copolymer O, 70/30 BU/ ST block copolymer +, 52/48 BU/ST...

Notwithstanding the general incompatibility of polymers and copolymers, polymers with solubility parameters that differ by 0.5 unit are compatible although their structures may differ. Thus, poly (methyl methacrylate) (PMMA), poly (ethyl acrylate) (PEA), poly (vinyl chloride) (PVC), and poly (butadiene-co-acrylonitrile) (90/10-60/40) form useful compatible blends because their solubility parameters are in the range 9.2-9.4. The difference in solubility parameters resulting in compatibility may be as much as one unit when the polymers are of relatively low molecular weight. 

Several TADs have also been studied as low-temperature modifiers of dienic polymers, especially butadiene homo- and copolymers. Isolated double bonds in these polymers react in the same sense as in the ene reaction (Scheme 90) to give urazole-substituted polymers 519 (79MI3). Depend-... 

Styrene polymers and copolymers are used extensively in making polystyrene plastics, polyesters, protective coatings, resins, and synthetic rubber (styrene-butadiene rubber). 

Styrene-butadiene rubber latex (SBR, GRS) and acrylonitrile-butadiene rubber latex (NBR) are two of the earliest to arrive on the market. Since then, many other types have appeared, with poly(vinyl acetate) and copolymers, acrylics (generally polymers and copolymers of the esters of acrylic acid and methacrylic acids), and carboxylic-SBR types being the major products. Since latices are aqueous emulsions, less... 

Details A colourless liquid, a starting material for making acrylates (with amide and acrylonitrile monomers) and other polymers and copolymers (with vinyl, styrene and butadiene), medical and dental materials. 

Chloro-1,3-butadiene (chloroprene) was originally synthesized in 1930. The material can polymerize spontaneously to an elastomer that has good resistance to oil and weathering. Commercial production of chloroprene rubber started in 1932. Since then, many types of polymers and copolymers were developed with the trivial generic name of neoprene. 

Polymers and copolymers of butadiene or isoprene with styrene can react with diborane. A suitable solvent for this reaction is tetrahydrofuran. Subsequent hydrolyses result in introductions of hydroxyl groups into the polymer backbones. The reactions with diborane are very rapid. Some side reactions, however, also occur. ... 

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