Carbon black in elastomer

DISPERSION OF CARBON BLACK IN ELASTOMERS 33.2.1 Effect of Morphology on Dispersibility of Carbon Black... 

A. M. Gessler, W. M. Hess, and A. I. Medalia, Reinforcement of Elastomers with Carbon Black Part 1. The Nature of the Carbon Black Part 2. Effect of Incorporating Carbon Black in Elastomers and Part 3. The Phenomenon of Reinforcement, Plast. Rubber. Process., (1978). 

W. M. Hess V, E, Chirico K. A, Burgess "Morphological Characterization of Carbon Blacks in Elastomer Vulcanizates," Paper A-17 Presented to Inti. Rubber Conf., Prague, Czechoslovakia, Sept. 17-20, 1973. 

The treatment of the kinetics of the dispersion of carbon black in elastomer blends [98] was the same here as it was for the various polymers (above). The agreement between the experimental and calculated values of the parameters a, o, k, and DR, were generally good. Conclusions from the results are summarized below. 

Coran, A. Y., Ingnatz-Hoover, F., and Smakula, P. C., The kinetics of the dispersion of carbon black in elastomer blends. Meeting of der Deutschen Kautschuk-Gesellshaft (DKG), Stuttgart, 1994. 

Besides the mixing sequence, the distributions of carbon black in elastomer blends are affected by viscosity, degree of unsaturation, and polarity of mbbers. For... 

It is an apparent consequence of the second role that SBS polymers with a molecular mass of about 80 000 behave like carbon-black-reinforced elastomers as illustrated in Table 11.16 in respect of tensile strength. 

Reinforcing fillers in general and high-structure carbon blacks in particular improve the extrusion characteristics of elastomers by decreasing extrudate swell. The extrudate swell decreases with increasing carbon black content [33]. 

There have been several attempts at models incorporating breakup and coalescence. Two concepts underlie many of these models binary breakup and a flow subdivision into weak and strong flows. These ideas were first used by Manas-Zloczower, Nir, and Tadmor (1982,1984) in modeling the dispersion of carbon black in an elastomer in a Banbury internal mixer. A similar approach was taken by Janssen and Meijer (1995) to model blending of two polymers in an extruder. In this case the extruder was divided into two types of zones, strong and weak. The strong zones correspond to regions... 

Similar to phenols, they can cause staining and are often used in conjunction with carbon black filled elastomers (e.g., tyres) — although carbon black itself has antioxidant capacity. For non-staining applications, e.g., polypropylene carpets, a stoically hindered amine is used, e.g.,... 

A possible mechanism for the chemical interaction of carbon blacks with elastomers on the basis of this model is discussed in their paper. 

Fig. 2. Evolution with strain of different parameters playing a role in the modulus of carbon black reinforced elastomer (from Ref.10>)...

It appears (Table 11) that the reinforcing ability exhibited by a HAF carbon black in polybutadiene or EPR is much lower after its surface has been previously modified by grafting of polystyrene M). Such results cannot, however, be associated with the elastomer s incompatibility towards the polystyrene grafts since poly-isoprene-grafted carbon blacks yield similar conclusions 65). 

V. Collin and E. Peuvrel-Disdier, Disperion Mechanisms of Carbon Black in an Elastomer Matrix, Elastomery, Vol. 9 (2005) Special Edition JSSN PL 1427-3519 see also V. Collin and E. Peuvrel-Disdier, presentation at the Conference of European Rubber Research Practical Improvements of Mixing Processer, Paterbom, Germany, January 25-26 (2005), pp. 219-241. 

From a fit of Equation (10) to spatially resolved relaxation curves, images of the parameters A, B, T2, q M2 have been obtained [3- - 32]. Here A/(A + B) can be interpreted as the concentration of cross-links and B/(A + B) as the concentration of dangling chains. In addition to A/(A + B) also q M2 is related to the cross-link density in this model. In practice also T2 has been found to depend on cross-link density and subsequently strain, an effect which has been exploited in calibration of the image in Figure 7.6. Interestingly, carbon-black as an active filler has little effect on the relaxation times, but silicate filler has. Consequently the chemical cross-link density of carbon-black filled elastomers can be determined by NMR. The apparent insensitivity of NMR to the interaction of the network chains with carbon black filler particles is explained with paramagnetic impurities of carbon black, which lead to rapid relaxation of the NMR signal in the vicinity of the filler particles. 

Figure 10.10 Schematic representation of the physical network structure in a carbon-black-filled elastomer [62]. The symbol - indicates elastomer - carbon black adsorption junctions. The length scales in this figure and the EPDM/carbon black volume ratio are fictional. For simplicity, none of the contacting carbon black aggregates, which form agglomerates, have been included...

There are also other substances that can be used as fillers that behave like carbon black in terms of the reinforcing action. One example is silica, but it has the drawback of its price, and the properties of the reinforced elastomer are generally inferior to those obtained with carbon black. These... 

It is a review written to analyse opinions concerning the behaviour of carbon black filled elastomers insofar as the carbon black affects the behaviour at or near failure, whether by abrasion, tear or tensile rupture. Behaviour at low or moderate extensions, which has been adequately reviewed, will not be considered unless it can be shown to bear upon reinforcement in the sense of the word implied in any dictionary definition1. It will be seen that a number of phenomena involved require the formulation of a specific model which shall be treated in considerable detail in the second half of this review. 

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