Butadiene-styrene copolymer latex

Table IV shows that dialysis is ineffective in cleaning the latexes for characterization. Earlier work (3,5) also showed that dialysis is ineffective in removing the adsorbed emulsifier and replacing the Na+ and K counterions with H ions. Others have also found that dialysis does not remove emulsifier completely. Brodnyan and Kelley (10) found that aqueous solutions of C14-tagged sodium lauryl sulfate equilibrated upon dialysis, but only 9.5% and 22% of the emulsifier was removed from latexes dialyzed under the same conditions. Matijevic et al. (11) dialyzed a butadiene-styrene copolymer latex prepared using rosin acid soap for 160 days and removed only about 50% of the emulsifier.

AaylonMe/butadiene/styrene copolymer latex, paper coatings Isobutylene/lsoprene copolymer latex, release coatings Aayllc/acrylonitrile copolymer latex, saturation... 

Styrene [100-42-5] (phenylethene, viaylben2ene, phenylethylene, styrol, cinnamene), CgH5CH=CH2, is the simplest and by far the most important member of a series of aromatic monomers. Also known commercially as styrene monomer (SM), styrene is produced in large quantities for polymerization. It is a versatile monomer extensively used for the manufacture of plastics, including crystalline polystyrene, mbber-modifted impact polystyrene, expandable polystyrene, acrylonitrile—butadiene—styrene copolymer (ABS), styrene—acrylonitrile resins (SAN), styrene—butadiene latex, styrene—butadiene mbber (qv) (SBR), and unsaturated polyester resins (see Acrylonithile polya rs Styrene plastics). 

At the same time, however, considerable research was being done, especially in Germany, on a novel process called emulsion polymerization, in which the monomer was polymerized as an emulsion in the presence of water and soap. This seemed advantageous since the product appeared as a latex, just like natural mbber, leading to low viscosity even at high soHds content, while the presence of the water assured better temperature control. The final result, based mainly on work at the LG. Farbenindustrie (IGF) (10), was the development of a butadiene—styrene copolymer prepared by emulsion polymerization, the foremnner of the present-day leading synthetic mbber, SBR. 

Witt [1959] studied under vacuum gamma-radi-ation-induced crosslinking in butadiene-styrene copolymers, homopolymers and mixtures of these homopolymers, (Table 11.9). The behavior of the styrene units in the copolymers and in the physical mixtures, was different. Gel fraction measurements showed that in the copolymer, the styrene units did inhibit the crosslinking of the polybutadiene. However, there was no evidence of such inhibition in the mill- and latex-prepared physical mixtures of the two homopolymers. 

Acrylonitrile/butadiene/styrene copolymer Ethyl acrylate binder, nonwoven fabrics AcrylatesA/A copolymer 2-Hydroxyethyl methacrylate Natural rubber latex Polyvinyl acetate... 

Upon mixing and subsequent hardening a three-dimensional polymeric network develops within the material, which is intimately combined with the three-dimensional stracture of the hardened cement paste. A variety of polymer dispersions may be combined with inorganic cements, as long as the polymeric material is sufficiently resistant to sustain the high-pH enviromnent of the cement paste. These may be thermoplasts, such as polyvinyl acetate, polyvirtyl chloride or polyacrylate thermosets, such as epoxides, polyesters, or polyurethanes and also elastomers, such as natural rabber latex or a butadiene-styrene copolymer. Polymer additions between 5% and 20% may be considered typical. 

Butadiene-styrene and butadiene-acrylonitrile copolymer latexes have also been epoxidized with peracetic acid [75]. 

Brako and Wexler [122] have described a useful technique for testing for the presence of unsaturation in polymer films such as polybutadiene and styrene-butadiene. They expose the film to bromine vapour and record its spectrum before and after exposure (Figure 3.12). This results in marked changes in the infrared spectrum. Noteworthy is the almost complete disappearance of bands at 13.691,10.99,10.36, and 6.10 pm associated with unsaturation. A pronounced band possibly associated with a C-Br vibration appears at 12.02 pm which is due to exposure to bromine vapour. Exposure of butadiene-styrene copolymer (Figure 3.12) to bromine vapour results in the disappearance of bands at 10.99 and 10.36 pm associated with unsaturation in the butene component of the copolymer. Some alteration of the phenyl bands at 14.28 and 10.37 pm is evident. The loss of a band at 6.45 pm and the appearance of a band at 5.88 pm are probably due to the action of acidic vapours on the carboxylate purifactant of the latex. 

Carboxylic elastomers have also been prepared by the addition of a carboxyl-bearing molecule such as thioglycollie acid, maleic anhydride, or acrylic acid to rubber in solvent, on the mill, or in latex. The preparation of a carboxylic polymer from a butadiene-acrylonitrile copolymer in an internal or Banbury mixer has been mentioned in the adhesives patent literature. The carboxylation of vulcanized natural rubber and of butadiene-styrene copolymers, including reclaimed stocks of these elastomers, by treatment with maleic an-... 

In contrast to this the name latex (Latin latex, liquid Greek A-ata, droplet) is derived from the naturally occurring rubber milk and is most widely used for aqueous synthetic organic polymer colloids, especially for the substitution products of natural latex, butadiene-styrene copolymer emulsions. 

Acrylonitrile—Butadiene—Styrene. ABS is an important commercial polymer, with numerous apphcations. In the late 1950s, ABS was produced by emulsion grafting of styrene-acrylonitrile copolymers onto polybutadiene latex particles. This method continues to be the basis for a considerable volume of ABS manufacture. More recently, ABS has also been produced by continuous mass and mass-suspension processes (237). The various products may be mechanically blended for optimizing properties and cost. Brittle SAN, toughened by SAN-grafted ethylene—propylene and acrylate mbbets, is used in outdoor apphcations. Flame retardancy of ABS is improved by chlorinated PE and other flame-retarding additives (237). 

Butadiene copolymers are mainly prepared to yield mbbers (see Styrene-butadiene rubber). Many commercially significant latex paints are based on styrene—butadiene copolymers (see Coatings Paint). In latex paint the weight ratio S B is usually 60 40 with high conversion. Most of the block copolymers prepared by anionic catalysts, eg, butyUithium, are also elastomers. However, some of these block copolymers are thermoplastic mbbers, which behave like cross-linked mbbers at room temperature but show regular thermoplastic flow at elevated temperatures (45,46). Diblock (styrene—butadiene (SB)) and triblock (styrene—butadiene—styrene (SBS)) copolymers are commercially available. Typically, they are blended with PS to achieve a desirable property, eg, improved clarity/flexibiHty (see Polymerblends) (46). These block copolymers represent a class of new and interesting polymeric materials (47,48). Of particular interest are their morphologies (49—52), solution properties (53,54), and mechanical behavior (55,56). 

Gilsonite is active as a fluid loss additive because the permeability of cement is reduced. Latex additives also act as fluid loss additives. They also act as bonding aids, gas migration preventers, and matrix intensifiers. They improve the elasticity of the cement and the resistance to corrosive fluids [921]. A styrene-butadiene latex in combination with nonionic and anionic surfactants shows less fluid loss. The styrene-butadiene latex is added in an amount up to 30% by weight of the dry cement. The ratio of styrene to butadiene in the latex is typically 2 1. In addition, a nonionic surfactant (octylphenol ethoxylate and polyethylene oxide) or an anionic surfactant, a copolymer of maleic anhydride, and 2-hydroxypropyl acrylate [719] can be added in amounts up to 2%. 

Concrete Styrene-butadiene copolymer latex additions on centrifugally cast concrete [271]... 

Styrene-based resins, extrusion of, 23 398 Styrene block copolymers, as mixed plastics compatibilizers, 21 454 Styrene-butadiene (SB) block copolymers, 20 324, 23 377, 393 Styrene-butadiene copolymer latex binders, 19 360... 

Styrene-butadiene rubber (SBR) latexes which are compatible with cementitious compounds are copolymers. They show good stability in the presence of multivalent cations such as calcium (Ca++) and aluminum (A1+++) and are unaffected by the addition of relatively large amounts of electrolytes (e.g., CaCl2). Outdoor exposure to... 

HMX HMX HMX HMX HMX HMX HMX HMX HMX HMX HMX HMX HNS NTO NTO/HMX NTO/HMX NTO/HMX PETN PETN PETN PETN PETN PETN PETN PETN PETN PETN RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX RDX TATB/HMX Cariflex (thermoplastic elastomer) Hydroxy-terminated polybutadiene (polyurethane) Hydroxy-terminated polyester Kraton (block copolymer of styrene and ethylene-butylene) Nylon (polyamide) Polyester resin-styrene Polyethylene Polyurethane Poly(vinyl) alcohol Poly(vinyl) butyral resin Teflon (polytetrafluoroethylene) Viton (fluoroelastomer) Teflon (polytetrafluoroethylene) Cariflex (block copolymer of butadiene-styrene) Cariflex (block copolymer of butadiene-styrene) Estane (polyester polyurethane copolymer) Hytemp (thermoplastic elastomer) Butyl rubber with acetyl tributylcitrate Epoxy resin-diethylenetriamine Kraton (block copolymer of styrene and ethylene-butylene) Latex with bis-(2-ethylhexyl adipate) Nylon (polyamide) Polyester and styrene copolymer Poly(ethyl acrylate) with dibutyl phthalate Silicone rubber Viton (fluoroelastomer) Teflon (polytetrafluoroethylene) Epoxy ether Exon (polychlorotrifluoroethylene/vinylidine chloride) Hydroxy-terminated polybutadiene (polyurethane) Kel-F (polychlorotrifluoroethylene) Nylon (polyamide) Nylon and aluminium Nitro-fluoroalkyl epoxides Polyacrylate and paraffin Polyamide resin Polyisobutylene/Teflon (polytetrafluoroethylene) Polyester Polystyrene Teflon (polytetrafluoroethylene) Kraton (block copolymer of styrene and ethylene-butylene)... 

Core-shell polymers were commercially introduced as impact modifiers for poly(vinyl chloride) PVC, in the 1960s. They are produced by a two-stage latex emulsion polymerization technique (Cruz-Ramos, 2000). The core is a graftable elastomeric material, usually crosslinked, that is insoluble in the thermoset precursors. Typical elastomers used for these purposes are crosslinked poly(butadiene), random copolymers of styrene and butadiene,... 

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. 

In Figure 6 the result of a rapid density gradient centrifugation is shown using this system. It deals with a graft copolymer latex of butadiene and styrene acrylonitrile. The gradient media are different mixtures of 3-butene-2-ol and ethylene glycol. 

Figure 6. Density and extinction profile in rapid density gradient centrifugation of a graft copolymer latex of butadiene and styrene acrylonitrile (c 5 mg L 1, N — 40.000 min1, t 10 = 60 min, v = 546 nm)...

Figures 4A and 4B are the ultra-thin cross-sections of OsOi+-stained two-stage (styrene//styrene-butadiene) and (styrene-butadiene/ /styrene) latex particles at the stage ratio of 50/50 (LS-10 and LS-11), respectively. Latex samples were mixed with a polymerizable monomer mix of butyl and methyl methacrylates, cured, and microtomed for examination. Figure 4A shows particle cross-sections much smaller than the actual particle size of LS-10. It appears that since the embedding monomer solution was a solvent for polystyrene, the continuous polystyrene phase was dissolved and small S/B copolymer microdomains were left behind. This is further evidence that the second-stage S-B copolymers phase-separated as microdomains within the first-stage polystyrene phase, as shown in Figures 1A and 1A. Figure 4B shows somewhat swollen and deformed particle cross-sections, suggesting that the first-stage cross-linked S-B copolymers were a continuous phase. Indeed, the former (LS-10) behaved like a hard latex, but the latter (LS-11) behaved like a soft latex.

Graft copolymers of thinned, gelatinized starch, including hydroxyethyl starch, with 1,3-butadiene-styrene latexes and other polymers that are claimed to have useful properties as paper coating materials are presented in Chapter 17. 

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