Miscibility studies of polystyrene/polyvinyl chloride blend in presence of organoclay

Polystyrene (PS)/ polyvinyl chloride (PVC) blends of different compositions, with and without organoclay (OC) were prepared by a solution casting method. PS and PVC were combined in ratios of 100/0, 90/10, 10/90, and 0/100. Local clay was treated with 0.5M NaCl to generate sodium clay (Na-clay). The Na-clay was subsequently modified using the cationic surfactant, cetylpyridinium chloride (CPC), at a concentration of 0.5 times that of Na-clay. The CPC-modified clay was denoted as organoclay (OC). The organoclay was dispersed in PS/PVC blends (90/10 and 10/90) with different weight percentages of OC (0%, 1%, 5%, and 10%). To evaluate the miscibility of PS/PVC blends, the blends with and without OC were characterized using Fourier-transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), X-ray diffraction (XRD), and scanning and transmission electron microscopy (SEM and TEM). The addition of OC to the PS/PVC blends produced exfoliated nanocomposites, as proven by XRD. The SEM and TEM micrographs showed that the PS/PVC(10/90) blend components were more miscible than those of the PS/PVC(90/10) blend, leading to favorable morphology.