Depolymerization of Polyester Fibers with Dimethyl Carbonate-Aided Methanolysis

Area of Science:

• Materials Science
• Green Chemistry
• Polymer Chemistry

Background:

• Polyester fibers, primarily poly(ethylene terephthalate), are widely used in textiles, with 60 million tons produced annually.
• Mismanaged textile waste poses significant environmental challenges, necessitating sustainable recycling solutions.

Purpose of the Study:

• To develop a low-temperature, rapid, and efficient method for recycling polyester fibers from textile waste.
• To selectively isolate high-purity dimethyl terephthalate (DMT) from various polyester textiles, including blended and colored fabrics.

Main Methods:

• Methanolysis of polyester fibers at 50 °C for 2 hours.
• Utilizing dimethyl carbonate as an ethylene glycol trapping agent.
• Incorporating decolorization processes for colored polyester textiles.

Main Results:

• Achieved a dimethyl terephthalate (DMT) yield of >90% from polyester fiber depolymerization.
• Successfully isolated DMT from blended polyester textiles and colored fabrics.
• Demonstrated the efficiency and selectivity of the developed recycling method.

Conclusions:

• The developed low-temperature methanolysis offers an efficient and sustainable route for recycling polyester textile waste.
• This method provides a viable strategy for recovering high-purity DMT, contributing to a circular economy in the textile industry.
• The process is applicable to diverse polyester textile waste streams, including those with challenging compositions.