Scale-Up Preparation\nof Biobased Poly(ethylene furanoate)\nBiaxial Orientation Films with Enhanced Mechanical and Barrier Properties\nfor Packaging

Poly(ethylene furanoate) (PEF) films, recognized for\ntheir promising\nbarrier and mechanical properties, offer a sustainable alternative\nto conventional petrochemical-based poly(ethylene terephthalate) (PET).\nIn this study, the effects of biaxial orientation parameters on the\nproperties of biaxially oriented PEF (BOPEF) and PET/PEF/PET multilayer\ncoextrusion films were comprehensively investigated to explore the\npotential of PEF for high-barrier packaging materials. Optimized conditions\nfor BOPEF films were achieved at a stretch ratio of 3.5, a temperature\nof 105 °C, and a rate of 100%/s, which enhanced the tensile strength\nto 145 MPa, the modulus of elasticity to 4.1 GPa, and the elongation\nat break to 88%. Moreover, these films exhibited superior barrier\nproperties with an oxygen permeability of 0.0083 barrer, a carbon\ndioxide permeability of 0.0031 barrer, and a water vapor permeability\nof 5.54 × 10<sup>–15</sup> g·cm/(cm<sup>2</sup>·s·Pa).\nUnder the same conditions, the mechanical properties and barrier properties\nof PET/PEF/PET films were further improved by adding 20% PEF to PET/PEF/PET\nfilms. The barrier properties of oxygen, carbon dioxide, and water\nvapor were improved by 32%, 50%, and 74%, respectively. The pilot-scale\nproduction validated the laboratory findings, demonstrating stability\nin film performance and consistent barrier properties, thus confirming\nthe feasibility of industrial-scale production for applications in\npackaging. The findings from this study not only underscore the potential\nof PEF as a high-performance material in packaging applications but\nalso illustrate the critical importance of process optimization in\nachieving the desired material properties. These results build a solid\nfoundation for the broader industrial application of PEF, enhancing\nits viability as a scalable and environmentally friendly alternative\nin the packaging industry.