Iran Polymer and Petrochemical Institute Polyolefins Journal 2322-2212 Articles in Press 2026 09 19 A comparative analysis of the effects of ultrasound on the characteristics of TiO₂-modified LDPE 2208 10.22063/poj.2026.35929.1402 EN Ali Alkhair Department of Chemistry, Polymer Technology and Packaging Solutions, Federal State Budgetary Educational Institution of Higher Education Russian Biotechnological University, Moscow, Russia Federation 0000-0002-9518-7781 Irina Anatol'evna Kirsh Department of Chemistry, Polymer Technology and Packaging Solutions, Federal State Budgetary Educational Institution of Higher Education Russian Biotechnological University, Moscow, Russia Federation 0000-0003-3370-4226 Anastasia Alexandrovna Fedorova Department of Chemistry, Polymer Technology and Packaging Solutions, Federal State Budgetary Educational Institution of Higher Education Russian Biotechnological University, Moscow, Russia Federation Journal Article 2026 08 05 This article aims to reduce economic losses from milk spoilage and deterioration by developing active, effective packaging materials based on low-density polyethylene with antimicrobial and antioxidant properties. The article examines how ultrasound affects the antimicrobial properties of low-density polyethylene films modified with 0.5%, 1%, or 3% titanium dioxide (TiO₂), including their effectiveness against gram-positive bacteria (Bacillus subtilis), gram-negative bacteria (Escherichia coli), yeast (Candida albicans), and fungi (Aspergillus niger). Additionally, the ability of the films to maintain the acid number of milk during 10 days of storage at 4 ± 2 °C was studied. To evaluate the impact of ultrasonic treatment and TiO₂ addition on forming new chemical bonds and groups within the polymer matrix, samples were examined via Fourier transform infrared spectroscopy (FTIR). The physical and mechanical properties, as well as the water vapor transmission rate (WVTR), of all polyethylene samples were studied. Ultrasound technology has shown great ability to prevent an increase in the acid number of stored milk, as the acid number of milk packaged in ultrasonically treated polyethylene containers decreased by 50% at a concentration of 0.5% TiO₂, as well as improving antimicrobial properties in the Candida albicans and Aspergillus Niger relationship. As for the physical and mechanical properties, the elongation at break was significantly improved using ultrasound. At a concentration of 3%, this resulted in an increase in elongation at break of 39.4% in the longitudinal direction and 43.2% in the transverse direction. Regarding the effect of ultrasound on the barrier properties of polyethylene, ultrasound technology decreased the water vapor transmission rate (WVTR) at all concentrations. WVTR decreased by 16.6% in polyethylene films with 3% TiO₂ that were ultrasonically treated compared to untreated films with the same concentration of TiO₂. http://poj.ippi.ac.ir/article_2208_94677bb808d2bc77815c8e6aa0724d10.pdf