MICROWAVE DIAGNOSIS OF RUBBER COMPOUNDS

The results of a study investigating the dielectric properties of rubb er compounds and their constituents in the frequency range of 5 to 24 GHz are presented. A completely filled short circuited waveguide techn ique was used to conduct these dielectric measurements. The influence of carbon black content in rubber was investigated for carefully prepa red rubber samples. The results showed that for all frequencies, the d ielectric constant increases as a function of increasing carbon black content. The variation of dielectric constant values decreases as freq uency increases. The presence of curatives in uncured rubber samples w as also detected, which indicates the sensitivity of microwaves to the chemical reaction triggered by curatives.