Effect of morphology of polyaniline nanomaterials on cure kinetics and properties of liquid crystalline epoxy nanocomposite

Three types of polyaniline (PANI) nanomaterials, nanorods with an average diameter of 30 nm, and nanospheres with average diameter of 30 and 300 nm were synthesized and employed as a curing agent and conducting nanofiller to prepare liquid crystalline epoxy (LCE)/polyaniline nanocomposites. The morphological effect of PANI nanomaterials on the cure behavior of LCE/PANI systems was extensively investigated using dynamic and isothermal differential scanning calorimetry (DSC) analysis. Dynamic DSC results showed that PANI nanorod was a more effective curing agent than nanospheres, because nanospheres retarded cure reaction to some extent compared with PANI nanorods. Isothermal DSC demonstrated that degree of cure was independent of PANI nanoshape. The effect of PANI morphology on the performance of cured LCE/PANI nanocomposites was also examined. Thermogravimetric analysis (TGA) illustrated that the LCE/PANI nanorod system exhibited an enhanced thermal stability than LCE/PANI nanospheres. LCE/PANI nanocomposites showed enhanced electrical conductivity regardless of PANI type compared with conventional epoxy composites (10-5 similar to 10-4 S cm-1). Scanning electron microscopy (SEM) revealed that macrophase separation was not observed in LCE/PANI nanocomposites. PANI nanorods are advantageous for improving the performances of LCE/PANI nanocomposites. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012