On some variations in rubber charge state during processing

It was detected that rubber displays electret properties dependent on mater ial history during processing. To prove this, a method of thermally stimula ted discharge (TSD) of electrets has been used. The method is sensitive bot h to carbon black introduction into rubber and to rubber compounds processi ng. Spectra of thermally stimulated currents (TSC) with current peaks of di fferent intensity and position on temperature scale were received by the TS D method. It has been postulated that TSC spectra reflect general regularit ies in distribution of ingredients during compounding and processing. A hyp othesis has been put forward that local mobility of powder and liquid ingre dients within rubber compound depends on polarization and charge state of m acromolecular 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 techniq ue to study filled rubber structures and properties. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.