Fabrication and characterization of polymer blends consisting of cationic polyallylamine and anionic polyvinyl alcohol

Thin sheets of polyallylamine (PAAm) and polyvinyl alcohol (PVA) blend were prepared by employing solution casting technique for potential membranes application. The blends were characterized by Fourier transform infrared (FTIR) and ¹H-NMR spectroscopy, scanning electron microscopy, thermogravimetric analysis, ultraviolet–visible spectroscopy, X-ray diffraction, and mechanical properties. The zeta potential, conductivity and rheological properties of PAAm/PVA blends were also studied. The FTIR spectrum reveals that the C–H asymmetric stretching vibration band of PVA at 2,928 cm^?1 disappeared in all the blend samples. Thermal stability of the blend membrane was better than pure polymers. The crystallinity of the PAAm/PVA blends was decreased, which may be due to the entanglement of PAAm in to PVA chains, which is also responsible for the improvement in the mechanical properties of the blends. Zeta potential decreases where as the conductivity increases as a function of temperature. Hydrophilicity is improved by addition of PVA to PAAm, which may be due to hydroxyl group of PVA. The blend solution shows non-Newtonian character of the liquid. By applying shear stress, increase in the effect of rarefaction was observed. The knowledge about the investigated parameters will be of vital importance for use of the blended material in membrane applications, especially where CO₂ separation is in focus. The membrane performance (separation properties) of the PAAm/PVA blended material is, however, not reported in the current article.