Influence of zinc acetate on HPMC/CMC polymer blend: Investigation of their composites’ structural, optical, and dielectric properties for dielectric capacitor applications

This research presents a novel eco-friendly polymer electrolyte composite designed for dielectric capacitors,
developed by combining hydroxypropyl methylcellulose (HPMC) and carboxymethyl cellulose (CMC) with
varying concentrations of zinc acetate (0.0, 1.5, 3.0, 6.0, and 12.0 wt%). The addition of zinc acetate significantly
improves the structural, optical, and dielectric properties of the HPMC/CMC composites. Structural
analysis using XRD reveals that increasing zinc acetate content reduces the crystallinity, promoting an amorphous
phase that enhances ionic conductivity. FTIR spectra display shifts in vibrational bands, confirming strong
interactions between zinc acetate and the polymer matrix. UV–Vis results demonstrate a reduction in the optical
bandgap, indicating improved charge transfer properties. Electrical performance assessments show that the
composite containing 12 wt% zinc acetate exhibited the highest AC conductivity and maintained a stable
dielectric constant across a wide frequency range (up to 10 kHz). The dielectric loss tangent values confirm
reduced energy dissipation with the addition of zinc acetate. Furthermore, the fabricated capacitors demonstrated
enhanced capacitance, stable leakage current, and superior discharge energy density, particularly in the
composite with 12 wt% zinc acetate. These findings underscore the potential of the HPMC/CMC–zinc acetate
composites as high-performance materials for dielectric capacitors in energy storage applications.