STATISTICAL-MECHANICAL THEORY FOR LIQUID-CRYSTALLINE POLYMER-SOLUTIONS

A statistical mechanical theory is presented for liquid-crystalline polymer solutions, where the liquid-crystalline polymer is regarded as a wormlike spherocylinder interacting by the hard-core repulsion and a soft (attractive or electrostatic) interaction with other spherocylinders. The theory is based on the following two assumptions: (1) the intramolecular excluded volume effect is not effective and (2) the interaction between pair of spherocylinders can be treated by the ''single contact approximation''. These assumptions are relevant to a polymer with a stiff backbone and not very long contour length. The theory is used to predict thermodynamic and spatial properties of isotropic solutions and also isotropic-liquid crystal phase equilibrium behavior. The predicted solution properties and phase behavior are favorably compared with experimental results for some selected stiff-chain liquid-crystalline polymers.