Toward Sustainable Packaging: A Toughened and Chemically Recyclable Biobased Poly(ethylene- <i>co</i> -1,4-cyclohexanedimethylene 2,5-furandicarboxylate) Copolyester with Balanced Barrier and UV-Blocking Properties

Biobased poly(ethylene furanoate) (PEF) is regarded as a crucial direction for the low-carbon and sustainable development of high-performance polyester materials. However, it faces challenges related to insufficient toughness. This study focused on enhancing the toughness of the PEF homopolyester while maintaining its high heat resistance, high strength, and other outstanding performance. By introducing 1,4-cyclohexanedimethanol (CHDM) as a third comonomer, a series of poly(ethylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate) (PEFG) copolyesters with balanced performance were developed and successfully scaled up to multikilogram production. Compared to commercially available and structurally similar petroleum-based poly(ethylene-co-1,4-cyclohexanedimethanol terephthalate) (PETG), the toughened PEFG copolyester exhibits a higher glass transition temperature, superior mechanical strength, and enhanced barrier performance. Additionally, PEFG exhibits an excellent UV-blocking property. More appealingly, PEFG can be chemically recycled under mild conditions to recover the 2,5-furandicarboxylate (FDCA) monomer with high purity and high yield. Accordingly, the successful scaled-up production of the high-performance and recyclable biobased PEFG material endows potential commercial opportunities for sustainable packaging.