The Dispersion of Carbon Black in Rubber Part I. Rapid Method for Assessing Quality of Dispersion

Abstract Carbon black is the most important reinforcing filler for rubbers. The incorporation of carbon black into rubber vulcanizates generally gives improved strength, extensibility, fatigue resistance, abrasion resistance, etc. In order to exert its beneficial influence on the properties of rubber vulcanizates, the carbon black must be sufficiently dispersed therein. Indeed, poor dispersion can, in itself, give rise to detrimental effects (e.g. reduced product life, poor performance in service, poor product appearance, poor processing characteristics, poor product uniformity, raw-material waste, high finished-product rejection rates, and excessive energy usage). These inadequacies are generally the result of the presence of rather large, undispersed agglomerates. The present work was initiated in order to develop an improved understanding of the carbon-black dispersion process including the understanding of factors which affect the kinetics of dispersion. The work described here is focused on methodolo...