Breakthrough in Textile Recycling: Preserving Spandex While Recycling Polyester

In a significant advancement for the textile recycling industry, researchers from Donghua University have unveiled a revolutionary chemical recycling method that effectively breaks down polyester while preserving the integrity of spandex and cotton. This discovery could transform the recycling of blended fabrics, which have historically posed challenges for sustainable fashion.

Published in the Journal of Hazardous Materials on August 1, the study highlights a solvent-based process that completely depolymerizes polyethylene terephthalate (PET) at a relatively low temperature of 80 degrees Celsius in just 80 minutes. This innovative method achieves an impressive 99 percent purity in terephthalic acid (TPA) recovery while ensuring that over 96 percent of the accompanying cotton and spandex remain structurally intact.

The ability to maintain the structural integrity of spandex and cotton is crucial, as the recycling of blended fabrics has long been a complex issue for the industry. Traditional methods often lead to the degradation of elastane, complicating the recycling process. Previous research successfully recovered polyester monomers but resulted in the destruction of spandex, rendering the fibers unusable for future textile applications.

To overcome these challenges, the Donghua team employed a combination of ethylene glycol, potassium hydroxide, and sulfolane—an industrial solvent known for its unique properties. This combination alters the chemical environment, allowing for more effective penetration and breakdown of the PET matrix without damaging the companion fibers. The researchers utilized advanced spectroscopy techniques and theoretical calculations to optimize the process, ultimately yielding high-quality monomers while preserving the other fibers.

Moreover, the study revealed that the process not only depolymerizes PET but also effectively removes dyes during recycling, addressing another critical challenge in textile waste management. By allowing colorants to move into the solvent phase, the method improves the quality of recovered fibers and simplifies the recycling process.

While these laboratory results are promising, the researchers caution that the technology’s commercial viability has yet to be established. Factors such as solvent recovery efficiency, environmental impact, and cost-effectiveness in an industrial setting remain to be thoroughly evaluated. Notably, the solvent sulfolane, while effective, has raised concerns regarding its safety profile, necessitating careful consideration in future applications.

As the fashion industry seeks sustainable solutions, Donghua University's breakthrough could pave the way for a more circular textile economy. The challenge now lies in scaling this innovative approach to handle real-world textile waste, which often includes a mix of various materials beyond polyester and elastane.

Source: wwd.com