ABSTRACT
This chapter deals with some of the relationships used to evaluate cohesion parameters from other properties of polymers. It considers the properties of oligomers. The polymer cohesion parameter can be thought of as the square root of the cohesive enthalpy per molar structural unit divided by the volume per molar structural unit. Preferred single cohesion parameter or Hildebrand parameter values for a few commonly encountered polymers. The best solvent for a polymer is not necessarily the corresponding monomer or oligomer made up of the same repeat units. Hildebrand parameters for polymers may be evaluated from polymer-liquid interaction parameters. A method that may be applied to cross-linked polymers and semicrystalline material such as poly(vinyl chloride), assumes that the degree of interaction with a liquid and swelling of a polymer in the liquid is a maximum when the cohesion parameters match. Lewis acid-base interactions are just as important in many polymer-liquid systems as they are in liquid-liquid systems, dominating the cohesion properties.
