Task-Specific Deep Eutectic Solvent for Efficient Dissolution and Further Accelerating Alkaline Hydrolysis of...

Area of Science:

• Materials Science
• Green Chemistry
• Chemical Engineering

Background:

• Polyester plastics, particularly polyethylene terephthalate (PET), are widely used but pose significant environmental challenges due to accumulation and difficult recycling.
• The continuous production and disposal of polyester waste threaten ecosystems and human health, necessitating innovative recycling solutions.

Purpose of the Study:

• To develop an efficient and sustainable method for the chemical recycling of polyester plastics.
• To investigate the use of a deep eutectic solvent (DES) for the dissolution and subsequent alkaline hydrolysis of PET and other polyesters.

Main Methods:

• A deep eutectic solvent (DES) was formulated using thenyl alcohol and choline chloride (ChCl).
• Polyethylene terephthalate (PET) was dissolved at 165°C for 20 minutes using the DES.
• Subsequent alkaline hydrolysis of the dissolved PET was performed at 100°C for 25 minutes to yield monomers.

Main Results:

• The designed DES efficiently dissolved PET, enabling complete alkaline hydrolysis into terephthalic acid (TPA) and ethylene glycol (EG).
• A high TPA monomer yield of 98.2% was achieved within 25 minutes.
• The DES demonstrated effectiveness in dissolving and hydrolyzing other polyesters, including poly(trimethylene terephthalate) (PTT) and poly(ethylene furanoate) (PEF).

Conclusions:

• The developed DES offers a feasible and sustainable approach for the chemical recycling of polyester waste.
• This method facilitates the recovery of valuable monomers from polyester plastics, promoting a circular economy.
• The study highlights the potential of DES in addressing the global challenge of plastic pollution.