On some variations in rubber charge state during processing

It was detected that rubber displays electret properties dependent on material history during processing. To prove this, a method of thermally stimulated discharge (TSD) of electrets has been used. The method is sensitive both to carbon black introduction into rubber and to rubber compounds processing. Spectra of thermally stimulated currents (TSC) with current peaks of different intensity and position on temperature scale were received by the TSD method. It has been postulated that TSC spectra reflect general regularities in distribution of ingredients during compounding and processing. A hypothesis has been put forward that local mobility of powder and liquid ingredients within rubber compound depends on polarization and charge state of macromolecular segments. This polarization determines kinetics of diffusion and adsorption processes in the compound and might influence compatibility of polymers. All above speaks in favor of using simple and fast TSD technique to study filled rubber structures and properties.