Butadiene Rubber BR

FIGURE 9.16 Resilience values for chlorobutyl rubber (CIIR), butadiene rubber (BR), unfilled natural rubber (NR), filled natural rubber (SRB), and polyurethane (PU) samples tested using a Shore rebound resibometer, an Instron compression tester and a scanning probe microscope (SPM). (From Huson, M.G. and Maxweb, J.M.,... 

The accelerated sulfur vulcanization of general-purpose diene rubbers (e.g., NR, styrene-butadiene rubber [SBR], and butadiene rubber [BR]) by sulfur in the presence of organic accelerators and other rubbers, which are vulcanized by closely related technology (e.g., ethylene-propylene-diene monomer [EPDM] mbber, butyl rubber [HR], halobutyl mbber [XIIR], nitrile rubber [NBR]) comprises more than 90% of all vulcanizations. 

FIGURE 26.43 Abrasion loss as function of pressure for a butadiene rubber (BR) tread compound on four different abrasive surfaces. O tarmac, Akron abrasive disk, A concrete I, A concrete II. (From Grosch, K.A. and Schallamach, A., Kautschuk, Gummi und Kunststojfe, 22, 288, 1969.)... 

FIGURE 26.62 Abrasion of OESBR and an 80 natural rubber (NR)/20 butadiene rubber (BR) blend tire compound as function of slip angle at a load of 76 N and a speed of 19.2 km/h. 

The enolethers give ozone protection but not ageing protection with natural rubber (NR) and polyisoprene (IR), styrene-butadiene rubber (SBR) and butadiene rubbers (BR), but are less... 

Butadiene can form three repeat units as described in structure 5.47 1,2 cw-1,4 and trans-, A. Commercial polybutadiene is mainly composed of, A-cis isomer and known as butadiene rubber (BR). In general, butadiene is polymerized using stereoregulating catalysts. The composition of the resulting polybutadiene is quite dependent on the nature of the catalyst such that almost total trans-, A, cis-, A, or 1,2 units can be formed as well as almost any combination of these units. The most important single application of polybutadiene polymers is its use in automotive tires where over 10 t are used yearly in the U.S. manufacture of automobile tires. BR is usually blended with NR or SBR to improve tire tread performance, particularly wear resistance. 

Some regularities, similar to Refs. 1718 21>, of viscosity variation in time under conditions of x = const were observed by the authors of Refs. 23,24,32-341 in extension of polyethylene and butadiene rubber (BR). Note that in Ref.34) the linear region of strain reaching the stationary flow was attained in extension of butadiene rubber. With further step-wise increase of x the effective viscosity grew and the time during which the stationary flow was attained increased significantly. References 23,24) will be discussed in more detail below. 

Fig. 7.28 Erosive dispersion of a carbon black agglomerate in butadiene rubber (BR) in simple shear flow, showing (a) the onion peeling mechanism, (b) a ribbon peeling mechanism and (c) both mechanisms. [Reprinted by permission from M. Astruc, Etude Rheo-optique des Mecanismes de Dispersion de Melanges sous Cisaillement Simple 1. Melanges concentres de polymeres immiscibles, 2. Melanges polymeres-charges poreuses, Doctoral Dissertation, Sophia Antipolis, Ecole des Mines de Paris, France (2001).]...

Butadiene rubber (BR) or Polybutadiene has an excellent abrasion resistance and a very low damping, but is, undiluted, too jumpy for use in tyres. In blends with SBR or natural rubber a good compromise of properties can be obtained. 

The polymers of rubber plastics have unsaturated hydrocarbon chain structure, since they are polymerized from alkadienes. The general formula of poly(l,3-butadiene) or butadiene rubber (BR) and polyisoprene or natural rubber (NR) is drawn in Scheme 12.5, where X is hydrogen in BR and methyl group in synthetic polyisoprene or NR. The free radical mechanism of thermal decomposition starts by homolytic scission of the alkyl C-C bonds. Two primary macroradicals (4 and 5) are formed for which the rearrangement... 

The worldwide demand for elastomers was estimated to be 19.44 million metric tons for 2008, excluding NR latex materials. Of this demand, 55% are synthetic elastomers of various kinds. Depending on their use elastomers have been classified into general purpose and speciality. The major general purpose elastomers are natural rubber, SBR rubber, PB rubber, isoprene rubber, and ethylene-propylene rubber. These rubbers are used in tires, mechanical goods, and similar applications. Specialty elastomers provide unique properties such as oil resistance or extreme heat stability. Although this differentiation is rather arbitrary, it also tends to classify the polymers according to the volumes used. About 74% of the rubbers used consist of SBR, butadiene rubber (BR), and ethylene-propylene rubber. 

The synthetic rubbers most frequently used for car tyres are emulsion and solution styreen/butadiene random copolymers (ESBR and SSBR) and butadiene rubber (BR). Truck tyres, however, often contain a certain amount of natural rubber (NR) or its synthetic version isoprene rubber (IR). The Tg-value of BR rubber as such can vary, depending on its chemical structure between -100°C and -20°C the Tg-value of SBR can, in principle, vary between -100°C and 100°C. 

In rubber mixes containing only a synthetic rubber, such as styrene-butadiene rubber (SBR) or butadiene rubber (BR), the effects of cure-system changes may not be as pronounced as they are in the case of NR. However, if even a relatively small amount of NR is present, the effects of cure-system changes on the vulcanization process parameters resemble those obtained with NR alone. 

Erdogan and co-workers [11] report a MS analysis of the gases evolved during the pyrolysis of NR, butadiene rubber (BR), SBR, styrene-butadiene-styrene (SBS) and styrene-isoprene-styrene thermoplastic elastomers and PS in the low (0-150 amu) mass range, using a quadrupole mass spectrometer. The results are interpreted using the variations in ion ratio as a function of temperature. 

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