Comparison of the Effect of ZnO or Oregano Essential Oil as anAntibacterial Agent on the Tensile and Hydrophilic Properties of PLA Film

This study compares the enhancement of Poly(lactic Acid) (PLA) films for food packaging applications through theincorporation of zinc oxide (ZnO) nanoparticles or oregano essential oil (OEO). Tensile testing revealed that adding۱% ZnO significantly increases yield stress (σy) from ۲۰.۶۷ MPa (pure PLA) to ۲۹.۰۱ MPa. Stress at break (σb)similarly increases and peaks at ۳۰.۸۷ MPa with ۱% ZnO. Elongation at yield point (εy) and elongation at break(εb), with ۱% ZnO, are enhanced to ۵.۸۹% and ۱۷۷.۰۲% respectively. Conversely, OEO decreases mechanicalstrength and increases flexibility and εb due to its plasticizing effect. Surface analysis via water contact angle (WCA)testing shows that both ZnO and OEO increase the hydrophobicity, but this is more evident in the presence of OEO.The highest level of hydrophobicity was observed at a concentration of ۳% of OEO. These findings underscore thepotential of ZnO and OEO to tailor PLA film properties for improved food packaging performance, and balancingthe mechanical strength with surface characteristics.

کلیدواژه ها:

Polymer Nanocomposites ، Blends and Alloys ، Poly(lactic acid) ، Oregano ، Zinc Oxide.