Liquid crystal epoxide network based on azoxy mesogen – electrical properties

¹ Institute of Physics, Technical University of Lodz, Wolczanska 219, 90-924 Lodz, Poland
² Department of Industrial and Materials Chemistry, Rzeszow University of Technology, W. Pola 2, 35-959 Rzeszow, Poland

^a e-mail: magdaw@p.lodz.pl

Received: 25 March 2013
Accepted: 15 July 2013
Published online: 22 August 2013

Abstract

In this work, electric properties of two matrices based on nematic epoxy monomers with azoxy groups are compared. The process of curing the monomers with DDM amine was monitored by means of dielectric spectroscopy at temperatures of 110 °C and 120 °C. In the next step, measurements of direct current conductivity were performed for the epoxy matrices cured at the temperature of 120 °C. The conductivity in the studied matrices was of the order of 10⁻⁹–10⁻⁷ S/m at temperatures between 150 °C and 170 °C. The conductivity of both the samples was of activation nature and their resistance grew rapidly below the temperature of 140 °C. Dielectric studies were also carried out for both the materials in a broad range of frequency and temperature. A relaxation process with similar activation energy was observed in both the cases. This process can be connected with the motion of polar azoxy groups present in the mesogen. An additional relaxation process appeared at higher temperatures in one of the cases, it was probably related to some structural change in the material.