Phase transition and rheological behaviors of a novel cellulose solution with 4-(ω-(methylimidazole)alkyloxy)-4′-(cyano)-biphenyls as a mesogenic unit

Abstract

4-(ω-(methylimidazole) hexyloxy)-4′-(cyano)-biphenyl (CbP) as a mesogenic unit was dissolved in 1-allyl-3-methylimidazolium chloride (AMIMCl) to generate cellulose side-chain liquid crystal. The influence of CbP on AMIMCl and cellulose/AMIMCl was investigated. Turbidity tests and Fourier-transform infrared spectra (FTIR) indicated that homogeneous solution of CbP/AMIMCl was formed and there was no chemical reaction between CbP and AMIMCl. The steady and dynamic shear measurements, polarized optical microscopy, differential scanning calorimetry and X-ray diffractomer were used to study the rheological behaviors and phase transition of cellulose/CbP/AMIMCl system. The results showed that there was an obvious liquid crystal phenomenon in cellulose/CbP/AMIMCl solution when the mass fraction of CbP in AMIMCl ranges between 2.5 and 3.5%, and solution temperature is 40–80 °C. The deviations from Cox–Merz rules suggested the destruction of intra- and intermolecular hydrogen bonds among cellulose, CbP and AMIMCl under shear deformation.