Abstract
The effect of six different types of activated carbons has been studied in view of their applicability as functional fillers upon the dielectric and microwave properties of natural rubber based composites. It is found that the textural characteristics of the studied active carbons exert influence both on the real part of dielectric permittivity and dielectric loss angle tangent, as well as on the microwave properties of the studied composites. The composite containing activated carbon on the basis of wooden material possesses the highest value of the total shielding effectiveness in comparison with the composites, containing another activated carbons. It has the lowest values of specific surface area, area and volume of micropores and the highest values of external surface area, volume of mesopores and average pore diameter. With gradually increasing the values of the indices in the first group and gradually decreasing the values of the indices in the second group, the value of total shielding effectiveness decreases. It is obvious that these indices have influence on the rubber matrix-filler particle interactions, such as multicontact chain adsorption to the surface of the filler. The spatial inhomogeneities formed give rise to polarization phenomena and to a frequency dependence of the dielectric properties.