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    Ecofriendly quince peel powder incorporated Polylactic acid biocomposite film
    (Sage Publications Ltd, 2024) Sen, Ibrahim; Eroglu, Murat; Severgun, Olcay; Kizil, Demet
    This study aims to develop sustainable, renewable and biodegradable biocomposite films from environmentally friendly materials. For this purpose, completely biodegradable polymer composites were prepared by mixing polylactic acid (PLA) with a new source, quince peel (QP), by solvent casting method, and their structural, mechanical and thermal properties were examined. The tensile strengths of the composites prepared using QP in proportions varying between 5% (P5Q) and 30% (P30Q) by weight vary between 21.13 +/- 0.80 and 12.01 +/- 0.10 MPa, and their elongations at break vary between 11.33 +/- 0.38 and 4.08 +/- 1.06 %. As the QP contribution increased, the tensile strength and breaking elongation of these composites generally decreased, while the elastic modulus also increased. Among these composites, whose elastic modulus varies between 1040.00 +/- 140.01 and 811.33 +/- 13.31 MPa, it was determined that the elastic modulus (1040.00 +/- 140.01 MPa) of the 20% QP added composite (P20Q) was higher than the others. When the thermal analysis of PLA/QP films were examined, it was observed that the glass transition temperatures (Tg) were between 58.54 and 51.45 degrees C and the melting temperatures (Tm) were between 167.71 and 164.28 degrees C, and these temperatures generally decreased with increasing QP doping. When the T50 values, which represent the temperature at which 50% of the composite materials decompose, were examined, it was found that the QP-added ones were higher than the pure composites. While this value was 317.96 degrees C in pure PLA composite, T50 values varied between 327.92 and 340.80 degrees C depending on the varying QP ratios. According to the XRD results performed to evaluate the crystalline properties of PLA composites containing quince bark, the crystallinity of pure PLA was determined as 19.5% and the crystallinity of composites containing 5, 10, 20 and 30 wt % QP additives was determined as 19.3, 18.3, 16.4 and 14.6%, respectively.
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    Evaluation of ultrasonic probe and bath sonication methods for the dispersion of TiO2 nanoparticles in PLA-based nanocomposites
    (Sage Publications Ltd, 2025) Severgun, Olcay; Eroglu, Murat
    Polylactic acid (PLA) is a promising biodegradable polymer that has someday, valuable applications in many industries. Its inherent brittleness and limited thermal stability, however, are restricting its wider use. In this study, titanium dioxide (TiO2) nanoparticles were added to PLA films to enhance their mechanical and thermal properties. The two different methods of dispersing the nanoparticles, ultrasonic-probe sonication (UPS) and bath sonication (BS), were investigated for their effectiveness to achieve homogeneous nanoparticle distribution. The findings revealed improvement in mechanical and thermal properties of PLA/TiO2 nanocomposites using both methods. UPS outperformed in achieving better dispersion, which led to measurably enhanced material properties. However, BS proved to be a valid and economically feasible method, producing composites with substantially improved properties compared to pure PLA, making it suitable for large-scale applications. Results indicated that the two approaches could thus be effectively utilized in creating high-performance nanocomposites from PLA intended for environmentally friendly biodegradable packaging, biomedical materials, or structural components requiring improved property performance.
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    Rosehip (Rosa rugosa) seed essential oil-loaded polyvinyl alcohol/ carboxymethyl cellulose biocomposites for active packaging applications
    (Elsevier, 2025) Eroglu, Murat; Severgun, Olcay; Mutlu, Busta
    This research focused on fabricating eco-conscious biocomposite films composed of polyvinyl alcohol (PVA) and carboxymethyl cellulose (CMC) incorporated with rosehip seed oil (RSO) for active packaging applications. The effects of RSO concentrations (1-5 %w/w) on the morphological, structural, mechanical, thermal, physical, optical and barrier properties as well as antioxidant and antibacterial features of the biocomposite films were systematically investigated. Scanning electron microscopy analysis demonstrated that the films' morphology could be tuned by varying RSO content, while Fourier transform infrared spectroscopyanalysis confirmed interactions between RSO and the polymer matrix. Moreover, the incorporation of RSO significantly influenced the mechanical properties increasing the tensile strength to 62.0 +/- 5.2 MPa, while reducing the elongation at break to 5.2 +/- 0.8 % at higher concentrations due to restricted chain mobility. The inclusion of RSO was observed to enhance the films' hydrophobicity, as well as their overall physical and optical characteristics. Oxygen and water vapor transmission rates decreased with RSO addition, whereas carbon dioxide transmission rate remained largely unchanged. In particular, the water vapor transmission rate was reduced from 1.31 g/m2 & sdot;h in neat PVA films to 1.02 g/m2 & sdot;h in PVA/CMC/5RSO film. Furthermore, the antioxidant activity of the films increased markedly in a concentration-dependent manner, with moderate RSO incorporation providing effective radical scavenging, whereas neat films showed only minimal activity. Additionally, the active films demonstrated strong inhibition against gram-positive bacteria ( (Staphylococcus aureus) and moderate activity against gram-negative bacteria ( (Escherichia coli). Consequently, these innovative multicomponent film formulations were determined to be appropriate for deployment in active food packaging solutions.