Thermodynamics of mixing in oligobutadieneurethane(meth)acrylate-oligoesteracrylate systems

The thermodynamics of formation of supermolecular and phase structures in oligobutadieneurethane(meth)acrylate-oligoesteracrylate mixtures was studied. The phase equilibrium in this oligomeric system was analyzed within the framework of the modified Flory theory. The temperature and concentration dependences of the thermodynamic functions of mixing in semidilute (left branch of binodal) and dilute (right branch of binodal) solutions were determined. There are three temperature regions functionally related to the upper critical solution temperature (UCST), which exhibit different patterns of variation of the thermodynamic parameters. The invariance of the thermodynamic functions of mixing with respect to the UCST is interpreted in terms of binodal invariance in the systems studied