Upcycling Fabrics: Valorization of Recycled Polyethylene Terephthalate (r-PET) Plastic Waste into Thermoplastic Polyester Elastomers (TPEE) for Fiber Spinning

Plastic waste has been one of the major sources of pollution in landfills and oceans. Although the upcycling of polymers has been proposed as a sustainable solution, multifunctional fibers based on upcycling concepts still require further investigation, which can extend the applications of environmentally friendly materials. In this work, we present an interesting strategy for fabricating stretchable, flexible, and durable fabrics via "up-polymerization" and electrospinning. Recycled polyethylene terephthalate (r-PET) waste films are converted to upcycled thermoplastic polyester elastomers (TPEE, PBT-co-PTMEG) via an esterification reaction and condensation polymerization. After dissolution in a trifluoroacetic acid (TFA)/dichloromethane (DCM) binary solvent system, the upcycled TPEE is electrospun into aligned fibrous membranes using a rotating drum. By adjusting the volume ratios of TFA/DCM or the polymer concentration, the diameters of the fibers can be controlled. Furthermore, the mechanical properties of the upcycled TPEE fabrics are determined by tensile measurement tests. The stress–strain curves show that the upcycled TPEE membranes exhibit good flexibility compared to commercial TPEE membranes. Moreover, the upcycled TPEE fabrics demonstrate excellent elastic recovery during cyclic tensile tests.