Styrene-butadiene copolymers applications

For the styrene-butadiene copolymer application, fit results of ANN models using one to six hidden nodes are shown in Table 12.7. Based on these results, it appears that only three, or perhaps four, hidden nodes are required in the model, and the addition of more hidden nodes does not greatly improve the fit of the... 

In the styrene—butadiene copolymer application, a series of quantitative ANN models for the as-butadiene content was developed. For each of these models, all of the 141 X-variables were used as inputs, and the sigmoid function (Equation 8.39) was used as the transfer function in the hidden layer. The X-data and Y-data were both mean-centered before being used to train the networks. A total of six different models were built, using one to six nodes in the hidden layer. The model fit results are shown in Table 8.7. Based on these results, it appears that only three, or perhaps four, hidden nodes are required in the model, and the addition of more hidden nodes does not greatly improve the fit of the model. Also, note that the model fit (RMSEE) is slightly less for the ANN model that uses three hidden nodes (1.13) than for the PLS model that uses four latent variables (1.25). 

Based on the above reactions, an overall mechanism for the hydrogenation of NBR catalyzed by Wilkinson s catalyst was proposed (see Scheme 19.4), which is also applicable to the kinetic performance of the homogeneous hydrogenation of PB [88] and styrene-butadiene copolymers [89], where K2 and Ks vanish. 

Styrene-Butadiene Copolymer Elastomers. SBR elastomers are employed in low-cost contact adhesives suitable for less-demanding applications—such as when exposure to elevated temperature is not likely, and when a bond of moderate strength is adequate. They can be dissolved in aliphatic hydrocarbon solvents and used to bond solvent-sensitive substrates like expanded polystyrene. 

Preparation, Properties and Applications of. High Styrene Content Styrene-Butadiene Copolymers... 

Plastics copolymerized from styrene, butadiene and acrylonitrile offer a wide application scope, thus high-impact polystyrene (HIPS, styrene-butadiene copolymer), styrene-... 

Aqueous dispersions of poly(vinyl acetate) and vinyl acetate-ethylene copolymers, homo- and copolymers of acrylic monomers, and styrene-butadiene copolymers are the most important types of polymer latexes today. Applications include paints, coatings, adhesives, paper manufacturing, leather manufacturing, textiles and other industries. In addition to emulsion polymerization, other aqueous free-radical polymerizations are applied on a large scale. In suspension polymerization a water-irnrniscible olefinic monomer is also polymerized. However, by contrast to emulsion polymerization a monomer-soluble initiator is employed, and usually no surfactant is added. Polymerization occurs in the monomer droplets, with kinetics similar to bulk polymerization. The particles obtained are much larger (>15 pm) than in emulsion polymerization, and they do not form stable latexes but precipitate during polymerization (Scheme 7.2). 

For electrostatic and steric stabilization, the particles can be viewed effectively as colloids consisting of a soft and deformable corona surrounding a rigid core. Colloidal particles with bulk elastomeric properties are also available. These particles, which are generally of submicron size, are developed and used as reinforcement additives to improve the Impact resistance of various polymer matrices [28-30]. The rubber of choice is often a styrene/butadiene copolymer. The presence of chemical groups at the matrix-filler interface leads to improved adhesion between them. Typically, the addition of about 30% by volume of these elastomeric particles increases the impact strength of a brittle glassy polymer like polystyrene by up to a factor of 10. For some applications, particles with more complex architecture have been... 

Equation (5-27), also known as the Gordon-Taylor11 equation, has found wide application to random amorphous copolymers. Figure 5-10 shows the experimental results for a series of styrene-butadiene copolymers along with the corresponding Tg s calculated from equation (5-27) with k = 0.34. (See problems at the end of this chapter for additional equations.)... 

Several other common industrial polymers are also used in biomedical applications [51]. Because of its low cost and easy processibility, polyethylene is frequently used in the production of catheters. High-density polyethylene is used to produce hip prostheses, where durability of the polymer is critical. Polypropylene, which has a low density and high chemical resistance, is frequently employed in syringe bodies, external prostheses, and other non-implanted medical applications. Polystyrene is used routinely in the production of tissue culture dishes, where dimensional stability and transparency are important. Styrene-butadiene copolymers or acrylonitrile-butadiene-styrene copolymers are used to produce opaque, molded items for perfusion, dialysis, syringe connections, and catheters. 

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 ... 

The most important application of SBR is in car tires and tire products, but there is also widespread use of the rubber in mechanical and industrial goods. SBR latexes, which are emulsions of styrene-butadiene copolymers (containing about 23-25% styrene), are used for the manufacture of foam rubber backing for carpets and for adhesive and molded foam applications. 

Rubber consumption is dominated by tyre production. In these, conveyor belts, and pressure hoses, thin layers of either steel wire or polymeric fibre reinforcement take the main mechanical loads. These layers, with rubber interlayers, allow flexibility in bending, whereas the reinforcement limits the in-plane stretching of the product. The applications are dominated by natural rubber and styrene butadiene copolymer rubber (SBR). Other rubbers have specialised properties butyl rubbers have low air permeability, nitrile rubbers have good oil resistance, while silicone rubbers have high and low temperature resistance. Rubbers play a relatively small role in this book, but the rubbery behaviour of the amorphous phase in semi-crystalline thermoplastics is important. 

There is a long, good tradition of concrete application with the styrene-butadiene copolymer for bridge pavements. The polymer to cement ratio (p/c) in most cases equals 0.15 (dry polymer mass) [61]. 

In a broad sense, polymer dispersions include both synthetic polymer dispersions and natural rubber (Table 6.1 ).The yearly production of synthetic polymer dispersions is about 10% of the overall polymer consumption [1]. Synthetic polymer dispersions are produced by emulsion polymerization. About half of these polymers are commercialized as waterborne dispersions. Carboxylated styrene-butadiene copolymers, acrylic and styrene-acrylic latexes and vinyl acetate homopolymer and copolymers are the main polymer classes (Table 6.2). The main markets for these dispersions are paints and coatings (26%), paper coating (23%), adhesives (22%) and carpet backing (11%) [2]. Polymer dispersions have also found an interesting market niche in biomedical applications (diagnosis, drug delivery and treatment [3]). 

Table 7.1 shows a number of excellent binders developed to date. Binders properties include - besides the actual binding - flexibility when used for electrodes, insolubility in the electrolyte, compactness, chemical and electrochemical stability, and easy application to electrode paints. The binder should be able to satisfy all of these properties simultaneously. This is a difficult task, and only two binders that comply with all these requisites have been found polyvinylidene fluoride (PVDF) and styrene-butadiene copolymer (SBR). 

Styrene-butadiene copolymers are used in toys, housewares, and medical applications.Thermoformed products include disposable food packaging such as cups, bowls, clam shells, deli containers, and lids. Bhster packs and other display packaging also use styrene-butadiene copolymers. Other packaging apphcations include shrink wrap and vegetable wrap. ... 

Looking at the historical development of the emulsion pol)nnerization, it is seen that the trigger factor in this development was the necessity for synthetic rubber in the wartime. The production of styrene/butadiene rubber (SBR) satisfied this requirement. Today, millions of tons of S)mthetic latexes are produced by the emulsion pol3merization process for use in wide variety of applications. In the S)mthetic latexes, the most important groups are styrene/butadiene copolymers, vinyl acetate homopol)rmers and copol)nners, and polyacrylates. Other synthetic latexes contain copolymers of ethylene, styrene, vinyl esters, vinyl chloride, vinylidene chloride, acrylonitrile, cloroprene and polyurethane. 

Chemical types of heat-activated adhesives include polyolefin, polyamide, polyester, PU, and styrene butadiene copolymers. These are described in Table 13.9. There are copolymer variants of each type, allowing a wide range of applications and performance properties. 

Second, in the case of styrene-butadiene copolymers which are used in various applications, the properties are largely dependent on the concentration of each monomer. For this reason, their detailed quantitative characterization is crucial. In this frame, methodology to obtain quantitative information for random styrene-butadiene copolymers has been developed from laser ablation coupled to Fourier transform ion cyclotron resonance mass spectrometry (LA-FTICR-MS) experiments. Contrary to other analytical techniques, the proposed methodology did not require pretreatment. When PS, butadiene rubber (BR), and SBR were laser-ablated... 

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