Facile green fabrication of boehmite-infused PVA nanocomposites with superior mechanical, thermal and electrical performance

Abstract

This study investigates the effect of boehmite (Bht) nanoparticles (NPs) on the thermal stability, mechanical attributes, electrical conductivity, impedance, and dielectric responses of polyvinyl alcohol (PVA) films. PVA/Bht nanocomposites (NC) were prepared using a water-based solution-casting method with Bht concentrations of 3, 5, 7, and 10 wt%. FTIR analysis confirmed effective hydrogen bonding interaction between PVA and Bht, indicating successful nanoparticle integration. XRD patterns showed the presence of Bht within the polymer matrix. Increased Bht loading significantly improved UV-B and UV-C blocking while reducing bandgap energy. FE-SEM and HR-TEM revealed homogeneous dispersion of Bht NPs and good interfacial compatibility with the PVA matrix. Thermal analysis revealed that the NC exhibited improved thermal stability along with glass transition and melting temperatures. Mechanical testing revealed improved tensile strength (TS) and Young's modulus (YM), accompanied by a reduction in elongation at break. Maximum TS (39.98 MPa) and YM (490 MPa) were recorded for PVA with 7 wt% Bht. Dielectric measurements showed that the dielectric constant reduced with increasing frequency, while AC conductivity increased. Among the materials, PVA containing 5 wt% Bht exhibited the highest conductivity at high frequencies (3.56 × 10⁻⁷ S/cm). Arrhenius and impedance analyses verified that electrical conductivity increased with temperature. Overall, the study demonstrates the potential of PVA/Bht NC as promising materials for flexible dielectric components and energy storage applications, enabling a renewable and efficient approach to material enhancement.