Styrene-butadiene rubbers carbon-black-filled

Fig. 6. Strain sweeps for the dynamic loss (shear) modulus G" of styrene-butadiene rubber samples filled with various carbon blacks (from [81])...

Of particular importance for detection of chemical or physical change in polymer materials are mobility filters, which are sensitive to differences in the numbers of molecules within a given window of correlation times. Within reasonable approximation such filters are relaxation filters. Here, Tj filters are sensitive to differences in the fast motion regime while T2 and Tip filters are sensitive to the slow motion regime. Which time window is of importance can be seen from Fig. 5.7 [101]. It shows a double-logarithmic plot of the mechanical relaxation strengths Hi(t) for two carbon-black filled styrene-butadiene rubber (SBR) samples as a function of the mechanical relaxation time T. They have been measured by dynamic mechanical relaxation spectroscopy. In terms of NMR, the curves correspond to spectral densities of motion. But the spectral densities relevant to NMR are mainly those referring... 

From about 1980, there have been extensive investigations of the shear viscosity of rubber-carbon black compounds and related filled polymer melts. Yield values in polystyrene-carbon black compounds in shear flow were found by Lobe and vhiite [L15] in 1979 and by Tanaka and White [Tl] in 1980 for polystyrene with calcium carbonate and titanium dioxide as well as carbon black. From 1982, White and coworkers found yield values in compounds containing butadiene-styrene copolymer [Ml, M37, S12, S18, T7, W29], polyiso-prene [M33, M37, S12, S18], polychloroprene [S18], and ethylene-propylene terpolymer [OlO, S18]. Typical shear viscosity-shear stress data for rubber-carbon black compounds are shown in Figs. 5(a) and (b). White et al. [S12, S18, W28] fit these data with both Eq. (56) and die expression... 

Dutta, N. K., Choudhury, N. R., Haidar, B., Vidal, A., Dormet, J. B., Delmotte, L., and Chezeau, J. M. 1994. High resolution solid-state NMR investigation of the filler-rubber interaction 1. High speed iH magic-angle spinning NMR spectroscopy in carbon black filled styrene-butadiene... 

A correlation was discovered [34] between the Mooney viscosity ML and the torque Mb on a Plasticorder and the corresponding equations for this dependency were derived for rubber compounds based on SBR (styrene-butadiene rubber) containing different types of carbon black and for compounds with one and the same type of carbon black but of different level of filling. 

Other earlier applications include those of Bletsos and co-workers [47] who produced time-of-flight ion MS of additives in polydimethylsiloxane and polytetrafluoroethylene, MS of organic additives in carbon black filled styrene-butadiene rubber [48] and oxidative ageing of antioxidants present on polymer surfaces [49, 36]. 

The identification of material heterogeneities based on differences in molecular motion is an important feature of NMR imaging. The importance of slow molecular motion for image contrast is demonstrated in Figure 31 with relaxation time parameter images through a partially aged sheet of carbon-black-filled styrene-co-butadiene rubber (SBR) (147). 

As a typical example, stress-strain curves for a pure styrene-butadiene rubber and for MWNTs/SBR composites are displayed in Figure 4.11. The elastic moduli, determined fi om the slope of the true stress against as well as other mechanical characteristics, are listed in Table 4.1. For the sake of comparison, are given, results obtained for a sample filled with 10 phr of carbon black (CB N330 fi om Cabot) and for a sample containing a double filling (5 phr of MWNTs -I- 10 phr of CB). 

When CIIR is blended with butadiene-styrene copolymer (SBR), as the concentrations of CIIR are increased, elastic rebound values are decreased linearly and traction is increased [48]. When CIIR is blended into natural rubber/polybutadiene carbon black-filled compounds, the compound shows a lower hysteresis and equal or better wet traction [49]. 

Powdered rubber based on E-SBR/carbon black compoimded in an internal mixer process is examined with respect to the advantages it affords in terms of enviromnental, handling and efficiency over conventional bale technology. This paper is the first part of a series of publications which discusses the individual rabber/filler systems in detail, and focuses on the system of carbon black-filled emulsion styrene butadiene rubber. It covers the selection of the raw materials, manufacture of products and their characterisation. 18 refs. 

Table 16.3 Mechanical properties of styrene-butadiene rubber (SBR) filled with nano-CaCOs (CC) and/or carbon black (CB). Adopted from ref. 71...

Rubber Chemistry and Technology 69, No.2, May/June 1996, p.273-6 STYRENE-BUTADIENE RUBBER FILLED WITH FLUORINATED CARBON BLACK. II. EFFECT OF CURATIVE LEVEL Ames K Gibala DS Hamed G R... 

Figure 12.6. Volume resistivity against filler loading for SBR composites filled with MWNTs and mixtures (10 phr CB + x phr (MWNTs) (A) and TEM image of a styrene-butadiene copolymer (SBR) containing a dual filling (5 phr CB + 5 phr MWNTs) (B). [Reprinted from L. Bokobza, M. Rahmani, C. Belin, J.-L. Bruneel, N.-E. El Bounia "Blends of carbon blacks and multwall carbon nanotubes as reinforcing fillers for hydrocarbon rubbers", Journal of Polymer Science Part B Polymer Physics, 46,1939,2008, permission from John Wiley and Sons].

The photo-oxidative behavior of commercial pol5miers is widely different. The most photo-oxidizable polymers are the imsaturated rubbers with labile R—H bond and are generally heavily filled with carbon black (an effective sun-screen see later) in outdoor applications. Similarly, rubber modified plastics, eg, high impact polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS), are more... 

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