Redesigned PHA Polyester Fibers: Sustainable PET Replacements to Reduce Microfiber Persistence*

Polyethylene terephthalate (PET) is widely used in textile production for its durability and versatility. However, the shedding of synthetic microfibers during washing and wear poses significant environmental challenges. Synthetic textiles are the largest contributor to microplastic pollution, with the accumulation of persistent microfibers imposing significant ecotoxicity in both aquatic and terrestrial ecosystems. In response to these challenges, biodegradable polyesters have emerged as potential alternatives to conventional synthetic textiles. Polyhydroxyalkanoates (PHAs) are a class of degradable polyesters that can be synthesized from bio-based feedstocks and through biological pathways. These materials offer reduced environmental persistence while maintaining performance properties comparable to PET. This study investigated the rheological and thermomechanical properties of advanced PHAs designed for textile applications. Melt extrusion studies were conducted to evaluate the feasibility of PHA fiber manufacturing, demonstrating the successful production of monofilaments with diameters less than 50 μm. Finally, biodegradation studies were designed and implemented to begin to investigate the persistence of the PHA microfibers in various aquatic environments.