ORDER-DISORDER PHASE-TRANSITIONS OF LIQUID-CRYSTALLINE POLYMERS WITH RIGID GROUPS IN THE SIDE-CHAINS - A LATTICE THEORY

We present, in this paper, a lattice model of liquid-crystalline polymers with rigid groups attached to a semiflexible main chain through semiflexible spacers. The polymers are modeled as sequences of isodiametric units allocated at the nodes of the face-centered-cubic lattice. The model allows study of the phase behavior in the liquid state of oligomers and polymers with various constitutions. Uniaxially ordered phases (nematic mesophases) with the rigid groups and/or the main chains partially aligned to the preferred direction are predicted to be stable in suitable conditions. The predicted general trends are in agreement with experiments. © 1990 American Institute of Physics.