Styrene-butadiene rubber , analysis

Results of a Fingerprint Analysis of a Masterbatch and Remill Mixing Process of a Styrene-Butadiene Rubber-Carbon Black (SBR-CB) Compound on a CK320E Intermeshing Mixer with PES3 Rotors (Harburg Freudenberger)... 

Although PFE lacks a proven total concept for in-polymer analysis, as in the case of closed-vessel MAE (though limited to polyolefins), a framework for method development and optimisation is now available which is expected to be an excellent guide for a wide variety of applications, including non-polyolefinic matrices. Already, reported results refer to HDPE, LDPE, LLDPE, PP, PA6, PA6.6, PET, PBT, PMMA, PS, PVC, ABS, styrene-butadiene rubbers, while others may be added, such as the determination of oil in EPDM, the quantification of the water-insoluble fraction in nylon, as well as the determination of the isotacticity of polypropylene and of heptane insolubles. Thus PFE seems to cover a much broader polymer matrix range than MAE and appears to be quite suitable for R D samples. 

Standard test method for rubber chemical analysis for polystyrene blocks in SBR (styrene-butadiene rubber) and styrene-reinforced lat-ices, ASTM Standard ASTM D3314-02, ASTM International, WestCon-shohocken, PA, 2006. 

Other reported TG-MS applications concern polybutadiene [153], styrene-butadiene rubbers [153], gums [14], polyisoprenes [52], polyurethanes [144, 146, 147, 166], ABS [144], chlorosulphonated polyethylene elastomer [169, 170] and elastomer blends (NBR/SBR/ BR) [13]. Table 1.5 summarises the use of advanced TG-MS systems in elastomer analysis. 

HSBR HTNR HXSBR ICTA Hydrogenated styrene butadiene rubber Hydroxyterminated liquid NR Hydrogenated carboxylated styrene butadiene rubber International Confederation for Thermal Analysis... 

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. 

Mixtures, formulated blends, or copolymers usually provide distinctive pyrolysis fragments that enable qualitative and quantitative analysis of the components to be undertaken, e.g., natural rubber (isoprene, dipentene), butadiene rubber (butadiene, vinylcyclo-hexene), styrene-butadiene rubber (butadiene, vinyl-cyclohexene, styrene). Pyrolyses are performed at a temperature that maximizes the production of a characteristic fragment, perhaps following stepped pyrolysis for unknown samples, and components are quantified by comparison with a calibration graph from pure standards. Different yields of products from mixed homopolymers and from copolymers of similar constitution may be found owing to different thermal stabilities. Appropriate copolymers should thus be used as standards and mass balance should be assessed to allow for nonvolatile additives. The amount of polymer within a matrix (e.g., 0.5%... 

Noriman and Ismail showed that incorporation of 10 phr ENR-50 in a blend of a styrene butadiene rubber (SBR) with recycled NBR (at 50/50 weight ratio) reduced both the temperature at 5 and 50% weight loss during a ther-mogravimetric analysis in a nitrogen atmosphere. The first was reduced from 360 to 353 °C, the latter from 480 to 392 °C. 

The reaction of carbenes with olefins to form cyclopropyl derivatives has been used to modify elastomers. Pinazzi and Levesque and Berentsvich et al. found that carbene addition had a significant influence on the properties of polydienes. Thermogravimetric analysis (TGA), flammability and oil resistance in NR and dichlorocarbene modified styrene butadiene rubber (DCSBR) blends were investigated by thermogravimetrie analysis as a funetion of different composition. The TGA plots confirmed the better thermal stability and flame resistance of DCSBR as well as its blends with NR. The amount of DCSBR in the blend significantly affected the properties of blends. 

Gauthier Catherine, Reynaud Emmanuelle, Vassoille V. Rene, and Ladouce-Stelandre Laurence. Analysis of the non-linear viscoelastic behavior of silica fllled styrene butadiene rubber. Polymer. 45 no. 8 (2004) 2761-2771. 

Pastor-Sempere [45] treated two styrene-butadiene rubbers with fumaric acid in a butan-2-ol/ethanol mixture. This resulted in improved adhesion in both cases, but the improvement with one formulation was significantly greater than the other. The lower peel strength was attributed to the presence of paraffin wax and zinc stearate. Roughening prior to treatment with fumaric acid resulted in additional improvements with both rubbers. Infrared analysis indicated that the fumaric acid was effective by introducing C=0 bonds and by reducing the concentration of zinc stearate. In addition, the fumaric acid caused a roughening of both rubbers. 

Figure 3.20. Compositional analysis of rubber products by TGA styrene-butadiene rubber (courtesey of TA Instruments).

Sircar and co-workers [8] compared experimental and data from the literature for the Tg of some common elastomers determined by different thermal analysis techniques, including DSC, TMTA, DMTA, dielectric analysis and thermally stimulated current methods. Elastomers examined include natural rubber, styrene-butadiene rubber, polyisoprene, polybutadiene, polychloroprene, nitrile rubber, ethylene-propylene diene terpolymer and butyl rubber. Tg values obtained by DSC, TMA and DMTA were compared. Experimental variables and sample details, which should be included along with Tg data were described, and the use of Tg as an indication of low temperature properties was discussed. 

Gauthier C, Reynaud E, VassoiUe R, Ladauce-Stelandre L. Analysis of the non-hnear viscoelastic behaviour of sUica filled styrene butadiene rubber. Polymer 2004 45 2761-2771. 

---