The enthalpy of dilution as a direct characteristic of the energy spectrum of intermolecular interaction in polymer solutions and gels

Calorimetric data on the concentration dependences of the enthalpy of dilution of polymer solutions are analyzed. The profiles of concentration dependences strongly depend on the nature of intermolecular interactions in polymer solutions and gels and on the specific features of their structure, including phase and relaxation states. Therefore, the concentration dependence of the enthalpy of dilution is treated as a spectral curve containing information on the energy state of the polymer solution and gel as a function of concentration. Theoretical models are considered that allow estimation of quantitative contributions from paired intermolecular and electrostatic interactions in solutions and contributions provided by the metastable state of a glassy polymer and by the presence of crystalline ordering.