Closed-Loop Recyclable Polyhexahydrotriazine Aerogels Derived From PET Waste

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Global plastic waste crisis driven by linear economy and unsustainable design.
• Polyethylene terephthalate (PET) is a major contributor to plastic pollution.
• Mechanical recycling of PET yields degraded quality; chemical recycling offers a better alternative.

Purpose of the Study:

• To chemically upcycle postconsumer PET waste into valuable monomers.
• To synthesize novel polyhexahydrotriazine (PHT) aerogels from recycled PET.
• To develop sustainable, recyclable, and thermally insulating materials.

Main Methods:

• Chemical upcycling of postconsumer PET waste into bifunctional aromatic amine.
• Incorporation of terephthalamide moieties for enhanced network formation via hydrogen bonding.
• Synthesis and characterization of polyhexahydrotriazine (PHT) aerogels.

Main Results:

• PHT aerogels exhibit low density, high mechanical robustness, and excellent thermal insulation.
• Developed PHT aerogels are recyclable via aqueous acidic depolymerization.
• High yield and purity of recovered monomers enable reuse with minimal property loss.

Conclusions:

• Upcycling PET waste into PHT aerogels provides a sustainable pathway to high-performance materials.
• The developed aerogels are designed for a circular economy, promoting resource efficiency.
• This approach addresses plastic pollution while creating valuable, eco-friendly products.