The Glass Transition of p-Alkyl-p'-Alkoxy-Azoxybenzene Mesophases
- 1 December 1981
- journal article
- research article
- Published by Taylor & Francis in Molecular Crystals and Liquid Crystals
- Vol. 76 (3-4) , 287-296
- https://doi.org/10.1080/00268948108076162
Abstract
An isomeric mixture of p-butyl-p'-methoxy-azoxybenzenes (IV) and the low melting eutectic mixture of p-butyl-p'-methoxy-azoxybenzenes with p-ethyl-p'-methoxy-azoxybenzenes (V) have been analyzed with differential scanning calorimetry (DSC). By quenching, it was possible to establish the glassy mesophase of both materials. Their glass transition temperatures are 207.6 K and 208.1 K, respectively, with an increase in heat capacity at T g of 129 JK−1 mol−1 and 102 JK−1 mol−1. As found previously with polymeric mesophases, the hysteresis is strongly reduced, while the ΔC p seems little affected by going from an amorphous glass to a mesophase glass. The melting, cold crystallization, and mesophase-isotropic melt transitions were also studied.Keywords
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