Effect of Zirconium oxide (ZrО2) Nanoparticles on the Mechanical, WVTR, and Antibacterial Properties of Polyethylene Polymer Matrix

A nanocomposite based on a low-density polyethylene (LDPE) matrix reinforced with zirconium dioxide (ZrO₂) nanoparticles was synthesized via single-screw extrusion and systematically characterized. Structural analysis confirmed homogeneous dispersion of ZrO₂ nanoparticles at lower concentrations (4.7% w/w), while agglomeration occurred at higher loadings (8.7% w/w), as evidenced by digital microscopy. FTIR spectroscopy revealed Zr-O vibrational modes at 421-468 cm⁻¹, verifying successful incorporation. Mechanical properties exhibited concentration-dependent behavior: tensile strength decreased by 31% (12.30→8.5 MPa) and elongation by 34% (482→320%) with 8.7% ZrO₂, attributed to stress concentration at nanoparticle clusters. Conversely, film thickness increased linearly (R²=0.98) with filler content, reducing water vapor transmission rate by 42% through enhanced tortuosity. The nanocomposites demonstrated remarkable antimicrobial efficacy, achieving 3-log reduction against E. coli at 8.7% loading, surpassing conventional food packaging materials. Thermal analysis (DSC/TGA) revealed improved thermal stability (↑15°C in decomposition temperature) without compromising LDPE's melt processability. These findings position ZrO₂-LDPE nanocomposites as advanced materials for active packaging, combining tailored mechanical performance, superior moisture barriers, and non-migratory antimicrobial protection while maintaining compliance with food-contact regulations.