Thermotropic liquid crystalline polyazomethine nanocomposites via in situ interlayer polymerization

Abstract

Nanocomposites of polyazomethine (PAM) with the organoclay C 12-MMT were synthesized by using the in situ interlayer polymerization method. The variations with organoclay content of the thermal properties, morphology, and liquid crystalline mesophases of the hybrids were determined for concentrations from 0 to 9 wt% C 12-MMT. The thermal properties and the morphologies of the PAM nanocomposites were examined by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide angle X-ray diffractometry (XRD), transmission electron microscopy (TEM), and polarizing optical microscopy (POM). The XRD analysis and TEM micrographs show that the levels of nanosize dispersion can be controlled by varying the C 12-MMT content. The clay particles are better dispersed in the matrix polymer at low clay contents than at high clay contents. With the exception of the glass transition temperature ( T g ), the maximum enhancement in the thermal properties was found to arise at an organoclay content of 1 wt%. Further, the PAM hybrids were shown to exhibit a nematic liquid crystalline phase for organoclay contents in the range 0–9 wt%.