Terminal Modification of Poly(Ethylene Furanoate) With Polycyclic Aromatic Hydrocarbons (PAHs): Leveraging π–π Interactions and Plasticization for Properties Enhancement

Poly(ethylene furanoate) (PEF), a sustainable alternative to poly(ethylene terephthalate) (PET), exhibits superior gas barrier properties but faces challenges in impact toughness and slow crystallization, limiting its industrial adoption. This study introduces a novel terminal modification strategy using polycyclic aromatic hydrocarbons (PAHs) to synergistically enhance PEF's performance through π–π stacking interactions, plasticization, and crystallization optimization. By incorporating PAHs (9-PBA/1-NA) as terminal modifiers, modified PEFB x and PEFN x polyesters demonstrate accelerated crystallization (15 vs. 33 min for neat PEF) and increased crystallinity (53% vs. 41%). The PAH-driven π–π stacking and V-shaped B(OH) 2 groups in 9-PBA promote chain folding and ordered packing, significantly improving oxygen barrier performance (40.9% reduction in permeability coefficient) and mechanical properties. Remarkably, PEFB 0.5 achieves a 277% increase in elongation at break and a 229% enhancement in tensile modulus compared to unmodified PEF. Furthermore, the method integrates reactive extrusion with injection molding, offering a scalable and industrially viable route for producing high-performance PEF with balanced processability, barrier properties, and mechanical strength.