Rubber-CB interactions

It is important to underline here that the schematic description of rubber-CB systems given in Figure 5.16 has to be considered as an "instant" view of materials, which remain essentially (pseudo) fluids above their glass temperature, i.e., practically in their whole processing and application temperature windows. We mean that rubber-CB interactions are likely to be dynamic, through continuous adsorption-desorption processes, at equilibrium at any given temperature. BdR content is therefore nothing else than the assessment of an equilibrium state at the temperature of the test, and therefore, is expected to decrease as extraction temperature increases (as readily observed indeed). If it were not the case, such complex materials would not have the capability to flow. 

As we have seen, hydrodynamic effects can somewhat be understood with respect to the works of Einstein, Guth, Gold, Simha, and others, but most of e technologically significant effects are due to rubber-CB interactions. BdR is the most significant evidence for rubber-carbon interactions, which is readily considered through the effective filler fraction, i.e. ... 

Involving BdR in theories on reinforcement is surely attractive, with respect to available experimental data, but because rubber-CB interactions have essentially a physical nature, they are reversible and, at a given temperature, the actual level of BdR (and hence of rubber-filler interaction) is at best an equilibrium level between competitive adsorption-desorption processes. As discussed below several quantitative models for the DSS effects have been developed. 

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