Polar/non-polar interactions in the granulation of organic substrates with polymer binding agents

Abstract

Calculations of the thermodynamic works of cohesion and adhesion (between substrate and polymer binder) based on a knowledge of either the partial cohesion/solubility parameters or surface free energies of the constituents have shown that there is a parabolic relationship between the reduced spreading coefficient (defined as the ratio of the work of adhesion to the work of cohesion) and the fractional polarity of the substrate. The relationship is independent of the method used to calculate these two dimensionless parameters but is specific for each polymer binder. It is possible, using the relationship, to explain the apparently anomalous results in the literature regarding the rank ordering of polymer binders and to predict the optimum binder for any particular substrate.