Abstract
This article presents the results on the effect of specific characteristics of four completely different carbon black types upon the dielectric and microwave properties of natural rubber based composites. It has been found that the proneness of carbon black particles to interact, aggregate and agglomerate affects the dielectric properties of the composites much more than their microwave ones. The proneness of carbon black particles to form chains, aggregates and agglomerates affects unfavorably the microwave properties of the composite thus filled. Fullerene carbon black having the lowest specific surface area and proneness to aggregate and agglomerate yields good microwave properties of the composites. The study demonstrates that the dielectric and microwave properties of rubber composites can be tailored via an appropriate selection of filler which specific chemical nature and structure are capable of yielding the parameters required for the particular applications.