Interplay of Phase Separations and Aggregations in Solutions of Rodlike Polymers

抄録

A theory is introduced to describe phase separations in solutions of end-to-end aggregates which are formed by intermolecuar physical bonding between rodlike molecules. In these solutions we have three different phase transitions:self-associations, phase separations and molecularorientations. On the basis of the Flory-Abe theory for polydisperse systems of rodlike particles, we examine the equilibriumsolution properties. By using themultiple-chemical equilibrium conditions for the molecularassociations, we derive the size distribution of theend-to-end aggregates in an isotropic and in a nematicphase. We show that the end-to-end aggregates cause an nematic-isotropic phase transition as well as the new types of phase separations. For various values of the association constant, we calculate phase diagrams in the temperature-concentration plane.