Polymers polystyrene butadiene

In the case of poly(vinyl chloride) plastics, the FWA is mixed dry with the PVC powder before processing or dissolved in the plasticising agent (see Vinyl polymers). Polystyrene, acrylonitrile—butadiene—styrene (ABS), and polyolefin granulates are powdered with FWA prior to extmsion (2,78) (see... 

Many of the most floppy polymers have half-melted in this way at room temperature. The temperature at which this happens is called the glass temperature, Tq, for the polymer. Some polymers, which have no cross-links, melt completely at temperatures above T, becoming viscous liquids. Others, containing cross-links, become leathery (like PVC) or rubbery (as polystyrene butadiene does). Some typical values for Tg are polymethylmethacrylate (PMMA, or perspex), 100°C polystyrene (PS), 90°C polyethylene (low-density form), -20°C natural rubber, -40°C. To summarise, above Tc. the polymer is leathery, rubbery or molten below, it is a true solid with a modulus of at least 2GNm . This behaviour is shown in Fig. 6.2 which also shows how the stiffness of polymers increases as the covalent cross-link density increases, towards the value for diamond (which is simply a polymer with 100% of its bonds cross-linked. Fig. 4.7). Stiff polymers, then, are possible the stiffest now available have moduli comparable with that of aluminium. 

Fig. 24.2. A two-phase polymer alloy, mode by co-polymerising styrene and butadiene in polystyrene. The precipitates ore a polystyrene-butadiene copolymer.

PBBs were also widely used as flame retardant additives in polymer formulations, e.g., synthetic fibers, molded plastics and plastic housings also in the manufacture of polycarbonates, polyesters, polyolefins and polystyrenes. Nixed ABS polymers (acrylonitrile -butadiene - styrene), plastics, coatings and lacquers also contained added PBBs to enhance fire-retardancy. 

The easiest technique to establish a polymer-photochromic molecule (PC) interaction is to dissolve the photochrome in a polymer solution from which the solvent is evaporated afterwards. DHI 7 has been incorporated by this technique into poly(methyl)- or poly( -butyl methacrylate), vinylidene chloride, acrylonitrile (Saran F), polycarbonate, and polystyrene-butadiene copolymer (Panarez). 

The DHI s may be solution cast with certain polymers. Examples of photochromic plastics prepared this way are poly (methyl methacrylate), poly (n-butyl methacrylate), copoly (vinylidene chloride-acrylonitrile) (e.g., SARAN F), polycarbonate, and polystyrene-butadiene (e.g., Panarez). 

Pelton RH (1988) Polystyrene and polystyrene-butadiene latexes stabilized by poly(A-isopropylacrylamide). J Polym Sci 26 9-18... 

A preliminary screening indicated that excellent impact could be obtained using 15-20 wt % butadiene based on the total polymer blend. At 20 wt % butadiene, several block polymers were screened for optimum impact and overall balance of properties. Two-component systems (block polymer-polystyrene) and three-component systems (block poly-mer-polybutadiene-polystyrene) were tried. The impact varied with the styrene content of the block polymer in both two- and three-component systems as shown in Figure 1. Subsequent work showed that the best overall balance of impact, flexural modulus, and heat distortion was obtained at 15% butadiene. 

Geveke, D.J. Danner, R.P., "Application of the Flory-Huggins Theory to the System Chloroform-Polystyrene-Butadiene Rubber," Polym. Eng. Sci., 31, 1527 (1991). 

Styrene is at the centre of an important industry, with a value of some 66 billion euros. The styrene production capacity is ca. 20 Mt/a worldwide. Most is obtained by ethylbenzene dehydrogenation and all the production is used for the synthesis of polymers (polystyrene, styrene-acrylonitrile, styrene-butadiene) used as plastics and rubbers in the manufacture of household products packaging, tubes, tires, and endless other applications (see also Chapter 7). 

Craze formation is a dominant mechanism in the toughening of glassy polymers by elastomers in polyblends. Examples are high-impact polystyrene (HIPS), impact poly(vinyl chloride), and ABS (acrylonitrile-butadiene-styrene) polymers. Polystyrene and styrene-acrylonitrile (SAN) copolymers fracture at strains of 10 , whereas rubber-modified grades of these polymers (e.g., HIPS and ABS) form many crazes before breaking at strains around 0.5. Rubbery particles in... 

Styrene is an important monomer or comonomer in the manufacture of a number of polymers polystyrene, acrylonitrile/butadiene/styrene, styrene/acrylonitrile, etc. There are two main processes for the manufacture of styrene. In one process styrene is made a coproduct with propylene oxide ... 

Tylac . CReichhold/Emulsion Polymers] Styrene-butadiene, butadiene acrylonitrile, polystyrene emulsxms. 

Figure 9-33. Selectivity of different polymer membranes to He-N2 separation as a function of nitrogen permeability (n, incm /(cm x atm x s)) (1) polyvinylidenechloride (2,4)polyethylene terephthalafe (3) polyvinylfluoride (5) polyvinylchloride (6) polyamide (7) plasfified polyvinylidene chloride (8) cellulose nitrate (9) polypropylene (lO)fluoroplast (26) (ll)co-polymer of isoprene (74%) and acryl-nitryl (26%) (12, 18, 20) different co-polymers of butadiene and acryl-rritryl (13) polyacrylate (14) polycarbonate (15) polyisobutylene (16) bulyl latex (17) co-polymer of vinyl chloride and vinyl acetate (19, 37) butyl acetate of cellulose (21) polyethylene vinyl acetate (22) polybutadiene (23) special polymer SKI-3 (24) natural latex (25) nitryl silicon latex (26) dimethyl silicon latex (27) special polymer SKS-30 (28) special polymer SKMS-50 (29) special polymer SKMS-30 (30, 34, 35) high-density, medium-densily, and low-density polyethylene (31) polyethylene with 5% soot (32) co-polymer of ethylene (90%) and propylene (10%) (33) co-polymer of ethylene (96.5%) and vinyl acetate (3.5%) (36) triacetate of cellulose (38) acetate cellulose (39) polystyrene.

Fishbein L. 1984. Toxicity of the components of styrene polymers Polystyrene, acrylonitrile-butadiene-styrene (ABS) and styrene-butadiene-rubber (SBR). Reactants and additives. In Jarvisalo J, Pfaffli P, Vainio H, eds. Industrial hazards of plastics and synthetic elastomers. New York, NY AlanR. Liss, Inc., 239-262. 

Hartsock DL, Stacy NE. Preparation, properties and applications of high styrene content styrene-butadiene copolymers. In Scheirs J, Priddy DB, editors. Modern Styrenic Polymers Polystyrenes and Styrenic Copolymers. New York Wiley ... 

Styrene serves as the monomer for the well-known polymer—polystyrene. It also serves as the source of many copolymers, that is polymers made from two monomers at varying compositions, such as SAN = styrene-acrylonitrile SBR = styrene-butadiene rubber (the major synthetic rubber) SBS = styrene-butadiene-styrene (a modem family of thermoplastic mbbers which are not cross-linked) and the well-known terpolymer ABS which is based on 3 monomers—acrylonitrile-butadiene-styrene. 

Viscosity modifiers, usually referred to as thickeners, are used in varying concentrations throughout the range of sealants and adhesives. They span a diverse range of chemical structures. Some of the more commonly encountered thickeners include poly(alkyl methacrylates) - homo and/co-polymers poly(alkyl acrylates) - homo and/co-polymers polystyrene acry-lonitrile-butadiene-styrene co-polymers poly(vinyl acetate) fumaric or maleic acid-based polyesters. 

Latex la- teks [NS latic. latex, from L. fluid] (1835) (pi lattices or latexes) n. (1) An emulsion of a polymeric substance in an aqueous medium. (2) The sap of the hevea (rubber) tree and other plants, or emulsions prepared from the same. Latices of interest to the coatings and plastics industry are based mainly on styrene-butadiene co-polymers, polystyrene, acrylics, and vinyl polymers and co-polymers. (3) Fine dispersion of rubber or resin, natural or synthetic, in water the synthetic is made by emulsion polymerization. Latex and emulsion are often used synonymously in the paint industry. Emulsified monomers once polymerized become solids or plasticized gel particles and not emulsions but aqueous suspensions. Lovell PA, El-Aasser MS (eds) (1997) Emulsion polymerization and emulsion polymers. John Wiley and Sons, New York. Martens CR (1964) Emulsion and water-soluble paints and coatings. Reinhold Publishing Co., New York. VanderhofF JW, Gurnee EE (1956) Motion picture investigation of polymer latex phenomena. TAPPI 39 (2) 71-77. VanderhofF JW, Tarkowski HL, Jenkins MC, Bradford EG (1966) Theoretical considerations of the interfacial forces involved in the coalescence of latex particles. J Macromol Chem 1 (2) 361-397. 

The polymerization is performed with sequential anionic polymerization. The polymers can be prepared as either a star block form or as a linear, multiblock polymer. The butadiene exists as a separate dispersed phase in a continuous matrix of polystyrene. The size of the butadiene phase is controlled to be less than the wavelength of light resulting in clear materials. 

It has been shown that in highly crystalline polymers having multiple transitions, such as poly(ethylene terephthalate), the glass transitions may be determined only by gas chromatography [170, 174, 177, 204]. The glass transition was also detected by gas chromatography in the copolymers acrylonitrile-vinyl acetate [201], acrylonitrile-a-methylsty-rene and the terpolymers of these monomers with vinyl acetate [207], polystyrene-butadiene [199], and styrene-tetrahydrofuran block copolymers [208]. 

Sedlar and co-workers [27] has described a gas chromatographic procedure, outlined below, for the determination of dilauryl p, P thiodipropionate antioxidant and its primary oxidation products in polyolefins, ethylene-vinyl acetate co-polymers, acrylonitrile-butadiene-styrene resins and high impact polystyrene. These workers examined the conditions under which di-lauryl-thiodipropionate and its oxidation products are hydrolysed, by 5 N methanolic potassium hydroxide at 80 °C, quantitatively to lauryl alcohol, thus making gas chromatographic determination possible. The method described next has the advantages of being rapid, accurate and simple. It has been applied successfully to the... 

Fig. 12-26 Effect of blending polymers, polystyrene, and polystyrene-butadiene copolymer [19].

Compositional analysis of polymeric rubber products by TGA has been used for many years to determine the quality and content of various rubber products (Kau 1988 Sircar 1997). A polystyrene butadiene rubber composition is illustrated in Fig. 3.20. The protocol for this analysis includes the following heating rate 20°C/min, 30 mg sample mass, and switching the purge gas from nitrogen to air at 500 °C. The results are illuminating for a 30-min determination of composition 8.4 mass% oil, which evaporates prior to the onset of polymer decomposition just below 400°C 50.4 mass% polymer, whose decomposition is complete by 500 °C, at which point the purge gas is switched to air 36.2 mass% carbon black, taken as the mass loss in air and 5.0 mass% residue, either ash or mineral filler plus ash. 

TBBPA has found use as a reactive flame retardant in the production of epoxy and polycarbonate resins added to circuit boards used in computers and in many other devices. In about 10% of cases TBBPA is used as an additive flame retardant, especially in the production of acrylonitrile-butadiene-styrene polymers, polystyrene, papers, textiles, televisions, office equipment and others. 

The photo-oxidation rates of polystyrene and polyacrylonitrile are considerably accelerated when they are grafted into polybutadiene. The rate of photooxidation of polystyrene becomes linear after 250 h whereas high impact polystyrene (polystyrene-butadiene) reaches the same stage after 25 h (Fig. 3.63). The rubber segment thus behaves as a photopro-oxidant for the polystyrene matrix and is itself destroyed in the process with the disappearance of the impact resistance of the polymer [761, 1922]. Thermal processing of high impact polystyrene increases the initial rate of photo-oxidation of the polymer... 

FIG U RE 4.17 The infrared spectrum of a polystyrene-butadiene co-polymer obtained using the heat and pressure method. 

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