Interfacial chain-growth polymerization enables polypropylene-like and circular polythioglycolide

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Polymers

Background:

• Polyolefins like isotactic polypropylene (iPP) are widely used but pose recycling challenges.
• Developing chemically circular alternatives with iPP-like performance is a significant research hurdle.
• Existing research often focuses on polyethylene alternatives, neglecting the need for iPP replacements.

Purpose of the Study:

• To introduce a high-molecular-weight poly(thioglycolic acid) (PTGA) as a chemically circular alternative to iPP.
• To achieve closed-loop recyclability and iPP-matched thermal, mechanical, and barrier properties.
• To overcome polymerization challenges hindering the synthesis of high-molecular-weight PTGA.

Main Methods:

• Developed an interfacial chain-growth ring-opening polymerization (ROP) method.
• Utilized the interface between a semicrystalline polymer surface and a monomer-organocatalyst solution.
• Enabled the synthesis of high-molecular-weight PTGA by circumventing transthioesterification side reactions.

Main Results:

• Synthesized high-molecular-weight PTGA with closed-loop recyclability.
• PTGA demonstrated iPP-like thermal properties, superior mechanical and barrier performance.
• Achieved excellent processability suitable for techniques like blow molding.

Conclusions:

• PTGA is a scalable circular polymer offering iPP-like properties.
• The interfacial ROP method effectively addresses limitations of traditional solution-phase polymerization.
• This work presents a viable, high-performance, and recyclable alternative for polyolefins.