Butadiene-vinyl pyridine copolymers

Butadiene-vinyl pyridine copolymers (c. 75% butadiene-25% vinyl pyridine) have been extensively studied. The rubbers have a low compatibility with other diene rubbers and have an extremely high rate of cure whilst the vulcanizates tend to become hard and brittle on heating. Although tyres showed good wear resistance, early tyre failure was noted because of body breaks and tread separation whilst the polymers became excessively hard and brittle during tyre running. For this reason they have not become successful as general purpose rubbers which depend so much on outlets in the tyre industry. 

Dispersions of copolymers of butadiene with acrylic acid or methacrylic acid in aqueous potassium hydroxide have been mentioned in the patent literature" as a dip for adhering rayon tire cord to rubber. The effect is most evident when carboxyl groups are present in the adhesive, the tie cement, and the cover stocks. The adhesive may be applied as latex, aqueous dispersion, or cement. A patent issued to the Dunlop Company Ltd." describes the use of a styrene-butadiene-itaconic acid copolymer with Gen-Tac Latex (GenCorp) in formulating an RFL (resorcinol formaldehyde latex) type adhesive for bonding a natural rubber compound to Nylon 66 and rayon tire cords. Brodnyan" also claims carboxylic adhesives for rayon, nylon, and Dacron cords. In this case, the tire cords were treated with a mixed polymer latex containing resorcinol-formaldehyde condensate, a butadiene-vinyl pyridine copolymer, an SBR copolymer, and a multifunctional copolymer from methyl acrylate, 2-hydroxy propyl methacrylate, and acrylic acid. A different approach was reported by Badenkov" whereby rayon or nylon tire cords were coated with... 

Mixing of the crystalline ingredients of oxidant, fuel elastomer binder (butadiene-2-methyl-5 vinyl-pyridine copolymer plasticized with the formal of diethylene glycol monobutyl ether) 26% by vol is done in a sigma blade mixer. The completed mix is blocked in a hydraulic press to form a chge suitable for extrusion. The extruded strand is cut into grain blanks which are cured at... 

The formation of coagulum is observed in all types of emulsion polymers (i) synthetic rubber latexes such as butadiene-styrene, acrylonitrile-butadiene, and butadiene-styrene-vinyl pyridine copolymers as well as polybutadiene, polychloroprene, and polyisoprene (ii) coatings latexes such as styrene-butadiene, acrylate ester, vinyl acetate, vinyl chloride, and ethylene copolymers (iii) plastisol resins such as polyvinyl chloride (iv) specialty latexes such as polyethylene, polytetrafluoroethylene, and other fluorinated polymers (v) inverse latexes of polyacrylamide and other water-soluble polymers prepared by inverse emulsion polymerization. There are no major latex classes produced by emulsion polymerization that are completely free of coagulum formation during or after polymerization. 

A very wide range of copolymers has been prepared in which a diene, particularly 1,3-butadiene, is the principal comonomer. Only a very small number have achieved commercial significance but one, styrene-butadiene rubber (SBR) has become the world s leading rubber in terms of tonnage consumption. Another, acrylonitrile-butadiene rubber (nitrile rubber, NBR) has been an important oil resistant rubber for some 40 years. It is these two rubbers which form the main subject matter of this chapter which also includes brief notes on two lesser known copolymers, butadiene-vinyl pyridine and butadiene-vinyl isopropyl ketone polymers and on novel alternating copolymers. 

Characterisation studies have been carried out on the following polymers. Low density polyethylene [60], high density polyethylene [60, 61], t-butyl methacrylate-4-vinyl pyridine copolymer [62], styrene butadiene copolymer [63], PS [64-70], polyethylene oxide [64], polypropylene oxide [71, 72], glycidyl methacrylate [73],... 

The isoprene units in the copolymer impart the ability to crosslink the product. Polystyrene is far too rigid to be used as an elastomer but styrene copolymers with 1,3-butadiene (SBR rubber) are quite flexible and rubbery. Polyethylene is a crystalline plastic while ethylene-propylene copolymers and terpolymers of ethylene, propylene and diene (e.g., dicyclopentadiene, hexa-1,4-diene, 2-ethylidenenorborn-5-ene) are elastomers (EPR and EPDM rubbers). Nitrile or NBR rubber is a copolymer of acrylonitrile and 1,3-butadiene. Vinylidene fluoride-chlorotrifluoroethylene and olefin-acrylic ester copolymers and 1,3-butadiene-styrene-vinyl pyridine terpolymer are examples of specialty elastomers. 

The phase-stabilized AN is prepd by mixing 90 parts AN, 10 ps K nitrate some water, heating the mixt to 140°F, drying and grinding to 40 micron size particles. The proplnt is compressed into grains. Example of compn AN 82.95, K nitrate 9.22, petroleum pitch 4.11 90/10 copolymer of l,3-butadiene/2-methyl-5 -vinyl pyridine 1.76 Amm dichromate 1.96%] EE)R.MacDonald A.M.Bedard, "Methods of Chemical Analysis of Cardeplex Propellant No 4760/A5 and Its Ingredients", CARDE TR426/63 (1963) (Cardeplex No 4760/A5 is a composite ammonium perchlorate-polyurethane proplnt. Analysis of fully cured product includes detns of Amm perchlorate, Al, ferric acetylacetonate, phenyl-/3 -naphthylamine, lithium fluoride total iron) FF)Anon,... 

Figure 13.6 Film cast from a 1 2 mixture of poly(styrene-co-butadiene) and poly(2-vinyl pyridine-co-butadiene) with about 15 mol% butadiene content (10 wt% solution of the copolymers in tetrahydrofuran). Dark areas, poly(styrene-co-butadiene) light areas, poly (2-vinyl pyridine-co-butadiene) [15]. Courtesy of Dr A. Schindler...

Catalysts of the Ziegler-Natta type are applied widely to the anionic polymerization of olefins and dienes. Polar monomers deactivate the system and cannot be copolymerized with olefins. J. L. Jezl and coworkers discovered that the living chains from an anionic polymerization can be converted to free radicals by the reaction with organic peroxides and thus permit the formation of block copolymers with polar vinyl monomers. In this novel technique of combined anionic-free radical polymerization, they are able to produce block copolymers of most olefins, such as alkylene, propylene, styrene, or butadiene with polar vinyl monomers, such as acrylonitrile or vinyl pyridine. 

The experimental copolymer composition data for styrene(Mi)-fumaroni-trile(M2) give a good fit to Eq. (7.86) with rj = 0.072 and r[ = 1.0 [33], but deviate markedly from the behavior predicted by the st-order Markov model with ri = 0.23. Penultimate effects have been observed in a number of other systems. Among these are the radical copolymerizations of ethyl methacrylate-styrene, methyl methaciylate-4-vinyl pyridine, methyl acrylate-l,3-butadiene, and other monomer pairs. 

Gallot has described the synthesis of poly(butadiene-b-vinyl naphthalene)while Szwarc has prepared p-xylylene block copolymers containing vinyl pyridine or styrene. These latter copolymers are prepared by producing p-xylylene vapor in the presence of "living" polystyrene or vinyl pyridine anions, or by the novel reaction of vinyl pyridine with p-xylylene radicals Block copolymers of ferrocenylmethyl methacrylate have also been prepared( 0). 

In order to obtain well-defined AB diblock copolymers by anionic polymerization and sequential monomer addition, some crucial conditions must be fulfilled (1) the carbanion formed by the second monomer must be more, or at least equally, stable than the one derived from the first monomer, and (2) the initiation of polymerization of the second monomer by the anion of the first monomer must be higher than the rate of propagation of monomer B. To fulfill these requirements, the monomers used must be added sequentially in the order of increasing electron affinity (e.g., a-methyl styrene (aMeSt) < St butadiene (Bd)< vinyl pyridine < methyl methacrylate (MMA)) and the nucleophilicity of the intermediate macromolecular carbanion A formed should at least match (though... 

PSBR Copolymer of vinyl pyridine, styrene and butadiene... 

The heparin Immobilized polyurethane surfaces (prepared by plasma grafting of 1 acryloyl benzotrlazole and subsequent hydrolysis/amlnatlon) are effective In suppressing thrombus formation. The adhesion of peripheral blood mononuclear cells was also lower on such modified surfaces [72]. Heparin immobilized on vinyl pyridine grafted styrene butadiene-styrene block copolymers also shows good biocompatiblllty. The adsorption of albumin and fibrinogen are reduced with the increasing graft levels and heparin content [41]. 

Favis and coworkers [51, 52] critically examined the relationship between the interfacial tension reduction in the presence of diblock copolymer additives and the dispersed phase morphology evolution as a function of the concentration of the interfacial modifier. Blends of PS/PE in the presence of PS-b-hydrogenated poly-butadiene-b-PS (Kraton, SEBS) [51] and of PE/PVC in the presence of Pl-l>-poly (4-vinyl pyridine) or PS-b-poly(acrylic acid) [52] were investigated. The authors unambiguously confirmed directly the relationship between interfacial tension and phase size, as predicted by the Taylor theory [280]. 

Polybutylcyanoacrylates [63], polyacrylics [64], polybutadiene [65], flame retardant PE [66], PS [67-70], PS - divinyl benzene copolymer [71], PS - acrylonitrile copolymer [72], acrylonitrile-butadiene-styrene terpolymer [73, 74], styrene-maleic anhydride copolymer [75], polyvinyl-cyclohexane [76], polyphenylene triazine [77], poly-4-vinyl pyridine [78], polyethylene sulfide [79], PSF [80], brominated PES [81], tetrafluoroborate doped polythiophene [82], polysiloxane [56, 83], vinyl pyrrolidone-methacryloxy silicone copolymer [50], polyvinyl indene [84], poly-E-lactide [3, 85, 86], epoxy resins [87, 88], polyaryl ether ketone [89, 90], ethylene... 

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