Investigation on two homologus series of ferroelectric hydrogen bond liquid crystals derived from camphoric acid and alkyloxy/alkyl benzoic acids

摘要

Two ferroelectric series comprising of 12 mesogens are investigated. In the first homologous series, Camphoric acid abbreviated as CA which is a ferroelectric ingredient, formed hydrogen bonds with benzoic acids with oxygen atom abbreviated as nBAO. The carbon chain of the benzoic acids varied from 5 to 12 atoms. Thus eight homologous members are synthesized. This mesogenic homologous series is represented as CA+nBAO. Similarly, Camphoric acid formed hydrogen bonds with alkyl benzoic acids abbreviated as nBA. The carbon number of the benzoic acids varied from 5 to 8. This mesogenic homologous series is represented as CA+nBA. Phases observed includes a new phase variant Smectic X*, and conventional phases C*, I* and G*. DSC thermograms exposed the Tc and corresponding Delta H magnitudes. Dielectric relaxations in smectic C* are discussed for a selected mesogen. The existence of oxygen in CA+nBAO facilitated presence of abundance poly phase morphism. (C) 2020 Elsevier B.V. All rights reserved.