CHARACTERIZATION OF DISPERSIONS

The quality of rubber and plastic products containing reinforcing pigments or fillers is highly dependent on uniform dispersion of these materials throughout the polymer matrix. Therefore, the considerable time and effort of a great number of workers have been directed at developing suitable test procedures for the characterization of dispersions. This paper reviews many of the procedures that have been developed over the past fifty years or so, with emphasis on those that are now in current use. The primary objective is to acquaint the reader with the available dispersion analysis techniques in conjunction with their relative strengths and weaknesses. The measurement of dispersion for different types of pigments in a number of different vehicle systems will be discussed. The main emphasis, however, is on the analysis of elastomeric compounds containing carbon black.