Synthesis, Characterization And Mesomorphic Properties of Side Chain Liquid Crystalline Oligomer Having Schiff Base Type Mesogenic Group

¹Usak University, Banaz Vocational School, Chemical Tehcnology Department, 64500 Banaz, Usak, Turkey

²Yildiz Technical University, Department of Chemistry, Davutpaşa, 34210 Esenler, Istanbul, Turkey

³Istanbul Technical  University, Department of Chemistry, 34469 Maslak, Istanbul, Turkey

Adv. Mater. Lett., 2014, 5 (6), pp 333-338

DOI: 10.5185/amlett.2014.amwc.1022

Publication Date (Web): Mar 23, 2014

Copyright © IAAM-VBRI Press

E-mail: hulyaelmali@yahoo.com

Abstract

A new liquid crystalline oligomer OLC was synthesized from its monomer having Schiff-base type mesogenic group MLC via free radical polymerization. The chemical structures of all compounds were confirmed using UV, FTIR, ¹H NMR, ¹³C NMR and MS spectroscopy. Schiff-base type thermotropic system based on side chain oligomer containing long aliphatic branching was studied to determine the change in mesophase behaviour of the Schiff-base type mesogenic groups. A combination of differantial scanning calorimetry (DSC) and polarize optical microscopy (POM) demonstrated that the oligomer behaves similar to its monomer and both of them exhibit enantiotropic SmC and monotropic SmX mesophases. The oligomerization of the liquid crystal monomer gives rise to decreased transition temperatures whereas it has no influence on the type and stability of the mesophase formed. Namely, simply through oligomerization, we can greatly vary transition temperatures of the mesogenic groups.

Keywords

Liquid crystal, schiff base, liquid crystal homopolymers, side chain liquid crystalline oligomer.