Carbon black stiffening effect

The property possessed by certain colloids of forming a gel-like structure on standing but which revert to a liquid form when subjected to agitation. The term has also been applied to the stiffening effect shown by uncured rubber compounds containing fillers, particularly carbon black. 

Thermal black Soft carbon black formed by the decomposition of natural gas (e.g., MT, medium thermal black). It has little stiffening effect, but imparts toughness, resilience, good resistance to tearing, and fair abrasion resistance. 

Reinforcement - The stiffening effect of solids, such as carbon black, on an unvulcanized elastomer mixture and the enhancement of the physical properties of the vulcanized compound, such as tensile, elongation, modulus, abrasion resistance, tear, etc. 

The dominant effects of carbon black on the tensile stress-strain curve of natural rubber can be seen in Fig. 6.29. Loading/unloading curves are compared for unloading from a strain of 2. The stiffening action of carbon... 

There is little doubt that developments in the use of nanofillers, both of elay and black varieties, and including carbon nanotubes, will have a significant effect on the rubber industry, particularly on the range and uses of thermoplastic elastomers over the years to come. The stiffening effects of some of these materials at quite low filler levels appear quite remarkable, and are sure to have an influence on the range of applications of elastomeric materials. 

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