Published online by Cambridge University Press: 25 February 2011
The two most important material properties for foam process modeling are liquid viscosity and surface tension. Several different pitches were examined including Ashland petroleum pitches and a synthetic mesophase pitch (Mitsubishi AR). Viscosities of isotropic pitch were measured at various temperatures above their softening points using an oscillating disk rheometer and found to be independent of shear rate and closely match the manufacturer's data. Only a very weak dependence of surface tension on temperature was found from calculations made from pendent drop measurements. The density of these materials, which was needed for the surface tension calculations, was measured using an elevated temperature mercury dilatometer. Transitions indicated by the volumetric results were also investigated by DSC.