Microstructural and Mechanical Studies of PVA Doped with ZnO and WO3 Composites Films

Polymer composites of ZnO and WO3 nanoparticles doped polyvinyl alcohol (PVA) matrix have been prepared using solvent casting method. The microstructural properties of prepared films were studied using FTIR, XRD, SEM, and EDAX techniques. In the doped PVA, many irregular shifts in the FTIR spectra have been observed and these shifts in bands can be understood on the basis of intra/intermolecular hydrogen bonding with the adjacent OH group of PVA. The chemical composition, phase homogeneity, and morphology of the polymer composites of the polymer film were studied using EDAX and SEM. These data indicate that the distribution of nanosized ZnO and WO3 dopants is uniform and confirm the presence of ZnO and WO3 in the film. The crystal structure and crystallinity of polymer composites were studied by XRD. It was found that the change in structural repositioning and crystallinity of the composites takes place due to the interaction of dopants and also due to complex formation. The mechanical studies of doped polymer films were carried out using universal testing machine (UTM) at room temperature, indicating that the addition of the ZnO and WO3 with weight percentage concentration equal to 14% increases the tensile strength and Young’s modulus. 1. Introduction The doping of nanoscopic organic or inorganic materials into polymeric matrices represents a strategic route to improve the performance of material characteristics like structural, physical, chemical, optical, electrical, and mechanical properties. These nanocomposites are of new class of materials made with nanosized fillers like metals, metal oxides, and so forth. Thus metal-polymer composites can be obtained by in situ and ex situ techniques [1–4]. In the in situ methods, metal particles are generated inside a polymer matrix by decomposition (e.g., thermolysis, photolysis, radiolysis, etc.) or chemical reduction of a metallic precursor dissolved into the polymer. In the ex situ approach, nanoparticles are first produced by soft-chemistry routes and then dispersed into polymeric matrices [5–9]. For the synthesis of metal-polymer composites the ex situ techniques are frequently preferred because of the high quality of the film. Over the past decades, transition metal oxides (TMOs) have been widely investigated for use in applications related to electronic, optical, and mechanical properties. Among these, TMOs, zinc oxide (ZnO), and tungsten oxide (WO3) are promising materials for the various above mentioned applications [10–13]. When these TMOs are incorporated in polymers, it improves their electrical,