Elastomers and Carbon Black CB

Whatever the filler, there are at least six families of parameters to consider when studying how the properties of a given polymer are modified  

No overall, coherent understanding of all those effects exists yet and only several, partial aspects are documented, in various extent, for certain classes of fillers. Due to its major role in rubber technology, CB is surely the material that has so far captured most of the attention and therefore, deserves a specific interest, whilst certain conclusions drawn in studying polymer-CB composites are not necessarily applicable to other systems. 

In most of their applications, elastomers are used in compounds where CB plays the key role in reinforcing mechanical properties. Not all properties are improved when adding CB particles to an elastomer and a balance of properties has to be achieved with respect to the application. In rubber compounds, CB amounts to 20-30% volume fraction. 

In rubber technology, a compounding formulation is generally described in phr (part per one hundred rubber) of component. Let us consider a typical general-purpose formulation for styrene-butadiene rubber (SBR) (Table 5.1). 

Zinc oxide is nowadays often used as an 80% weight predispersion in EVA specific gravity of such a predispersion is 2.90 g/cm so 5 phr ZnO correspond to 6.25 phr predispersion. 

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