Use of microwave dielectric loss spectroscopy for characterisation of natural rubber/carbon black composites

Microwave dielectric loss spectroscopy (MDS) has shown remarkable potential as a tool for the observation of changes in elastomer network structure wi thin the interphase region of natural rubber/carbon black composites. Durin g crosslinking (non elemental sulphur system) the dielectric loss progressi vely increased. However, during ageing at high temperature the dielectric l oss decreased. Parallel studies on the unfilled matrix yielded no such vari ation in dielectric loss. It was therefore concluded that the changes in mi crowave responses were related to the development of the interphase during curing and its subsequent destruction during ageing. The microwave response was related to the composite mechanical properties as a function of ageing time. The effect of stabiliser was also investigated.