REINFORCEMENT OF UNCURED AND CURED RUBBER COMPOSITES AND ITS RELATIONSHIP TO DISPERSIVE MIXING - INTERPRETATION OF CURE METER RHEOGRAPHS OF CARBON-BLACK LOADED SBR AND CIS-POLY-BUTADIENE COMPOUNDS

A new approach has been proposed to characterize the state of mixing of carbon black-loaded-SBR and cis-polybutadiene compounds. The basic concept is that carbon black aggregates, present when the dispersion is imperfect, affect the modulus of the uncured compound more than that of the cured compound. From cure meter curves, the torque values before and after curing can be related to moduli which can, in turn, be analyzed to give information on the state of aggregation of the carbon black. An equation is proposed which correlates the relative modulus values with volume fraction of carbon black, morphology (packing or state of aggregation) of carbon black, and polymer-carbon black interaction.