Dynamic β-Amino Sulfonamides for the Synthesis of Covalent Adaptable Networks

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Thermosets offer excellent properties but are non-recyclable, contributing to plastic pollution.
• Covalent Adaptable Networks (CANs) utilize dynamic covalent bonds to enable recyclability.
• Existing CANs using beta-amino amides (BAAs) face challenges with monomer stability.

Purpose of the Study:

• To investigate beta-amino sulfonamides (BASA) as novel, robust linkers for Covalent Adaptable Networks (CANs).
• To evaluate the performance and recyclability of BASA-based CANs compared to existing systems.
• To demonstrate the potential of BASA-based CANs for sustainable materials.

Main Methods:

• Synthesis of CANs using bisfunctional vinyl sulfonamide cross-linkers based on BASA.
• Investigated the kinetics of amine exchange reactions via (retro)aza-Michael reactions between 140-180 °C.
• Characterized the thermomechanical and rheological properties of the synthesized CANs.
• Assessed the recyclability and performance retention over multiple cycles.

Main Results:

• BASA linkers exhibit faster amine exchange reactions than BAAs.
• Released vinyl sulfonamide monomers from BASA are more stable and resist homopolymerization.
• BASA-based CANs show tunable properties and maintain mechanical/rheological performance over five recycling cycles.
• The developed CANs demonstrate improved thermal stability and recyclability.

Conclusions:

• Beta-amino sulfonamides (BASA) are effective and robust linkers for creating recyclable Covalent Adaptable Networks (CANs).
• BASA-based CANs offer a promising sustainable alternative to conventional thermosets with enhanced stability.
• This work advances the development of recyclable polymers for reducing plastic waste.