Evaluating Contaminant Effects and Blend Ratios on the Alkaline Hydrolysis of Polyester Textile Streams

The increasing amounts of discarded textiles represent a potentially valuable resource that could be reclaimed, for example, by chemical techniques. This work underscores the significance of utilizing chemical recycling techniques for multicomponent fabrics under mild reaction conditions to investigate the reusability of recovered components. We present a method for recovery of cotton, elastane, and nylon from polyester blends through mild alkaline hydrolysis supported with a phase-transfer catalyst. To juxtapose the impact of these various fibers on the depolymerization of the polyester component into terephthalic acid (TPA), consistent reaction conditions were maintained. The average TPA yield (by mass) was 93.9 ± 2.8% for pre-consumer materials and 89.5 ± 3.1% for post-consumer materials. This comparative analysis provides insights into factors contributing to the observed decrease in the TPA yield. Inimitable to this study, an analysis of the reuse potential of recovered cotton via tensile strength was performed. The average cotton recovery (by mass) was 95.9 ± 0.8%. Comprehensive material characterization of all recovered components was performed. This research paves the way for a deeper understanding of the potential contamination of TPA, the quality of recollected fibers, and what components of a mixed textile stream act as potential "disruptors" to recyclability.