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

The increasing amounts of discarded textiles represent a potentially valuable resource that could be reclaimed. This work underscores the significance of advancing chemical recycling techniques for multi-component fabrics under mild reaction conditions. We present a method for nondestructive recovery of cotton (C), elastane, and nylon from polyester (polyethylene terephthalate (P)) textile blends through alkaline hydrolysis, supported with a phase-transfer catalyst. Consistent reaction conditions were maintained while evaluating various pre-consumer blends to assess their impact on the depolymerization of P component into terephthalic acid (TPA). The average TPA yield (by mass) exceeded 93.9 ± 2.79 % for pre-consumer materials and 89.5 ± 3.14 % for post-consumer materials. This work also explored the reuse potential of cotton recovered from the P:C textiles and examined any alterations in tensile strength post-hydrolysis. The average C recovery (by mass) exceeded 95.9 ± 0.784 %. Extensive material characterization for all components of the system was conducted. This research paves the way for a deeper understanding of the potential contamination by small molecules, and the quality of unreacted fibers within this mild alkaline chemical process.