Mechanical, Thermal, and Optical Properties of Zinc Cobaltite-Filled Polyvinyl Alcohol Composite Films

Abstract

In this study, zinc cobaltite (ZCO)-reinforced polyvinyl alcohol (PVA) composite films were prepared using a solvent casting method, and the effect of ZCO content (0.5-10 wt% relative to PVA) on the structural, thermal, mechanical, and optical properties of PVA was investigated. Effective integration and nearly uniform dispersion of spinel-structured ZCO within the PVA matrix were verified by XRD and SEM studies. Strong interfacial contacts between PVA hydroxyl groups and the oxide surface were revealed by FTIR-ATR findings, which resulted in limited polymer chain mobility. While slight drops in melting temperature were linked to decreased crystallinity at larger loadings, thermal research showed an increase in glass transition temperature and enhanced high-temperature stability with increased ZCO content. Maximum elongation at break (302%) was attained at intermediate filler percentage; however, mechanical testing revealed a notable improvement in tensile strength, reaching 54.94 MPa for the 5 wt% ZCO composite. A shift from an optically transparent insulator to a UV-active functional composite was indicated by optical investigations that showed improved UV absorption, band-gap reduction, and greater optical conductivity. These findings demonstrate ZCO as a useful multifunctional filler for PVA films with potential uses in optoelectronic coatings and UV shielding.