Ring-Opening Polymerization Enables Access to High-Performance Aliphatic-Aromatic Polyamides with Chemical...

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Polyamides (PAs) are vital engineering thermoplastics.
• Chemical recycling of PAs to monomers presents significant challenges.
• Developing sustainable routes for PA production and recycling is crucial.

Purpose of the Study:

• To develop a facile method for synthesizing functionalized benzo-fused caprolactams (BLM).
• To investigate the ring-opening polymerization of BLM monomers.
• To establish efficient chemical recycling of the resulting polyamides for a circular economy.

Main Methods:

• Synthesis of a series of functionalized benzo-fused caprolactams (BLM).
• Ring-opening polymerization of BLM monomers to form poly(BLM) (P(BLM)).
• Chemical recycling of P(BLM) using a mixed catalyst (t-BuOK and La[N(SiMe3)2]3) in dilute solution.

Main Results:

• Successfully synthesized various functionalized BLM monomers.
• Produced P(BLM) with high thermal stability, improved water resistance, and tunable mechanical properties.
• Achieved efficient chemical recycling of P(BLM) to monomers at 100-150 °C, demonstrating closed-loop circularity.

Conclusions:

• The developed BLM monomers and their polymerization offer a pathway to high-performance semiaromatic polyamides.
• The efficient chemical recyclability of P(BLM) supports a sustainable circular economy.
• This approach provides tunable material properties and enhanced water resistance for advanced applications.