Study of Thermal Behavior and Activation Energy of Various Polymer Nanocomposite Blend Membranes

The solution casting method was used to synthesize nanocomposites of polymethyl methacrylate (PMMA) and polystyrene (PS) polymer with graphene oxide (GO). It was determined that the conductivity of the PS/GO and PMMA/GO polymer nanocomposites was ionic and electronic, respectively. The thermal conductivity of the nanocomposites was investigated with regard to the impact of crystallinity and free volume. This paper reports a differential scanning calorimetric (DSC) study of PMMA/GO (1%) and PS/GO (1%) and nanocomposite blends of PMMA and PS prepared in different ratios by weight percentage of PMMA/PS (80:20, 60:40, 50:50, 60:40, 20:80) with 1% of GO using the solution casting method. The samples were analyzed using a DSC instrument at heating rates of 5°C/min, 10°C/min, and 20°C/min in the temperature range of 50–160°C. Fourier transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD) studies of the blends showed that the crystalline phases of PS and PMMA depended on the GO percentage in the composite solutions. Significant shifts were seen in FTIR, XRD, and DSC analyses, and DSC and TGA thermograms of the nanocomposite blend confirmed the formation of a PS/PMMA blend and demonstrated a significant change in thermal behavior with the blend ratio. The activation of the pure and blended polymers was determined through their glass transition using different isoconversional methods.