Styrene-butadiene copolymers, analysis

These properties determine how carbon black will be distributed within the blend. These properties are not those of the filler but are the essential properties of the matrix. The matrix thus has strong influence on particle distribution. SEM studies showed that high vinyl polybutadiene and styrene-butadiene copolymers had morphologically identical carbon black distribution. However, their mechanical properties were very different. NMR analysis indicated that the difference in mechanical behavior is related to the interaction and more precisely to the molecular motions in rubbery matrix. 

Zmierczak et al.4 have investigated the catalytic hydrocracking of non-vulcanized rubber (SBR, styrene-butadiene copolymers) over superacid solids, consisting of sulfated Zr and Fe oxides. Figure 6.7 shows the GC-MS analysis of the liquids produced at 400 °C over sulfated Fe203, with assignments of the main peaks. Three types of product are observed C5-C9 paraffins produced from the butadiene blocks of the polymer, alkylbenzenes derived from the... 

Autohesion of polyisoprene rubber (Natsyn 2200, a synthetic high-cis-l,4-polyiso-prene) and styrene-butadiene copolymer has been studied. Both elastomers were reinforced by carbon black and crossHnked by a sulfur-based system (see Table 24.1) [3]. The glass transition temperatures of the elastomers were not significantly changed by crossHnking and were equal to -66°C and -53°C for the IR and SBR, respectively, as measured by DSC analysis. 

HOM Homma, T. and Fujita, H., Frrrther sedimentation analysis of styrene-butadiene copolymer rabber, J. Appl. Polym. Sci., 9,1701,1965. 

FIGURE 3.7 PyTOF analysis of styrene/butadiene copolymer at 750°C. 

This study combines a thermal analysis technique -thermogravimetry with atmospheric pressure chemical ionization mass spectrometry and applies the combined technique to the third question. The literature contains references relating to the analysis of styrene butadiene copolymers using thermal analysis techniques (1-5). Pyrolysis - mass spectrometry (5) and vacuum thermogravimetry - mass spectrometry (7) have also been used to investigate polymers such as polystrene and styrene butadiene rubber. 

Ruch, D., Boes, C., Zimmer, R., Muller, J.-E, Migeon, H.-N. (2003) Quantitative analysis of styrene butadiene copolymers using S-SIMS and LA-FTICRMS. Applied Surface Science, 203-204, 566-570. 

The polymers described in this chapter are industrial-grade materials, and consequently some of the examples may contain additives and/or may be chemically modified. Polymers in various morphological forms may be analyzed, and these include films, fibers, solid pelletized and powdered products, and dissolved/dispersed materials in liquids such as paints and latex products. Also, the same base polymer, such as a styrene-butadiene copolymer, for example, may exist in a rubber, a resin, or a plastic. In general, reference will not be made to the original source of the polymer samples. Because infrared spectroscopy is more widely used than the Raman method, the authors will focus more on the applications of this technique. However, the Raman method, which is complementary to the IR method, does have important and unique applications in the polymer analysis, especially with regard to the determination of the fundamental polymer structure and its... 

Fraga [11] has also described an infrared thin-film area method for the analysis of styrene-butadiene copolymers. The integrated absorption area between 6.6 and 7.2 pm has been found to be essentially proportional to total bound butadiene, and is independent of the isomeric type of butadiene structure present. This method can be calibrated for bound styrene contents ranging from 25 to 100%. 

Other workers who have investigated the applications of NMR spectroscopy to the analysis of unsaturation in polybutadiene and styrene-butadiene copolymers inclnde Carlson and Altenau [26], Carlson and co-workers [27], Binder [28, 29], Braun and Canji [30, 31], Hast and Deur Siftar [32], Silas and co-workers [33], Cornell and Koenig [15], Neto and Di Lauro [34], Binder [28], Clark and Chen [35] and Harwood and Ritchey [36]. 

Fig. 13. An example of Mochel s curve analysis method [30, 31] for determining block styrene in styrene-butadiene copolymers...

Comparison of a PS-PMMA blend with a corresponding copolymer gave information on the chemical drift. In the analysis of a competitive modified vinyl polymer sample by SEC/FTIR, some of the components of the binder could be readily identified (vinyl chloride, ethyl methacrylate, acrylonitrile), and an epoxi-dized drying oil additive was also detected. An analysis of styrene-butadiene copolymers, including a determination of the styrene/butadiene ratio and of the micro structure of the butadiene units cis/trans, l,2-/l,4-units), was performed by Pasch et al. 

This technique has been used extensively for the determination of functional groups, in polymers and copolymers (Chapter 3) and in comonomer analysis (Chapter 4). Both these aspects are concerned with the determination of polymer structure. For example the distinction between free and combined vinyl acetate in vinyl chloride - vinyl acetate copolymers (Section 3.4.4) or the elucidation of the structure of methylmethacrylate (MMA) - glycidyl methacrylate copolymers (Section 3.6.1) or the elucidation of the various types of unsaturation occurring in styrene - butadiene copolymers (Sections 3.9.3, 3.9.4). Typical infrared (IR) spectra of copolymers are shown in Figures 6.1 to 6.4. 

Functional group analysis and the determination of monomer unit concentrations can be used to determine the monomer composition and hence the empirical formula of a copolymer or terpolymer. Thus, if a styrene-butadiene copolymer contains 6% (6/56 moles) bound butadiene and 94% (94/104 moles) bound styrene, then the empirical formula is ... 

The compositional analysis of styrene butadiene copolymers is discussed in Section 2.1.1. 

With this in mind, Tanaka and co-workers [43] proposed a new method for the characterisation of the sequence distribution of styrene units in styrene-butadiene copolymers by a combination of selective ozonolysis of the double bonds in butadiene units and GPC measurements of the resulting products. His method is based upon high resolution GPC analysis of the alcohols corresponding to styrene sequences obtained by scission of all the carbon-carbon double bonds of butadiene units. The ozonolysis-GPC method has already been proven to be a very powerful tool to characterise the sequence distribution of styrene units and the tacticity in random, partially blocked, and triblock styrene-butadiene copolymers [39, 44-48] in this study a new analytical method of the sequence distribution of 1,2 units in polybutadiene was investigated on the basis of the ozonolysis-GPC method. 

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