Analysis of transitions of liquid crystals and conformationally disordered crystals by temperature-modulated calorimetry

Abstract

Temperature-modulated calorimetry was used to investigate a known liquid crystal (LC) and a well-characterized conformationally disordered crystal (CDC). Both crystals consist of a rigid, aromatic segment and a flexible, aliphatic spacer. The results provide conclusive experimental evidence for the thermodynamic reversibility of the isotropization transition of a polymeric LC over their full transition range, and the irreversibility of the isotropization of CDCs of macromolecules.