Preparation of PAM/PVA blending films by solution-cast technique and its characterization: a spectroscopic study

Polyacrylamide (PAM) and poly(vinyl alcohol) (PVA) were blended with different weight percentages (70/30, 50/50, 30/70) using solution-cast technique. The prepared films were studied by different characterization techniques. The effect of PVA content on PAM blends was investigated by Fourier transform infrared (FTIR), ultra violet visible (UV–vis), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Different mechanical properties of blends were also studied. Significant changes were observed in FTIR, UV–vis, TGA, SEM and mechanical analysis which revealed interactions between the two polymers. FTIR spectra showed the presence of hydrogen bonding between PAM and PVA and hydrophilic nature of the blends. Different optical properties were studied by UV–vis spectroscopy. The weight loss, as a function of temperature of blends, was analyzed by TGA. The results obtained from different experimental techniques were supported by SEM image analysis. FTIR analysis confirmed the conclusion on the specific hydrogen bonding between –CONH₂ groups in PAM and –OH group in PVA. These results showed the change in the thermal stability and mechanical properties. FTIR analysis revealed that a blend ratio of 50/50 wt% had maximum intermolecular interaction between two polymers. It was finally concluded that blend films with the above ratio display higher thermal stability and improved mechanical properties. Due to changes in interactions, the optical parameters were also changed.