Conductive Imidazolium Side Chain Liquid Crystal Polyacrylates Prepared from Postpolymerization Functionalization

摘要

Hydroxide and tetrafluoroborate salts of imidazolium polyacrylates have been prepared from postpolymerization functionalization of a brominated precursor containing mesogenic side chains followed by anion exchange. The ionic polyacrylates possessed molecular weights in the range 1.1-1.3 x 10(4) g.mol(-1). Differential scanning calorimetry measurements and polarizing optical microscope observation indicated that the resultant ionic polyacrylates exhibited smectic C and A liquid crystal phases over a temperature range of about 60 degrees C. Electrochemical impedance spectroscopy measurements show that ionic conductivities of the hydroxide salt were much higher than those of the tetrafluoroborate salt for the imidazolium polyacrylates at the same temperature. The maximum ionic conductivity of the random hydroxide salt of imidazolium polyacrylate in the smectic A phase reached 4.45 x 10(-2) Scm(-1). The ionic polyacrylates were successfully aligned by mechanical shearing in the smectic A phase. Ionic conductivities of the sheared samples were more than 1 order of magnitude higher than those of the random samples in the solid state. (c) 2014 Wiley Periodicals, Inc.