Building From the Ground Up: A Procedural Guide to Locally Controlling Bond Exchange Kinetics in Dynamic...

Area of Science:

• Polymer Chemistry
• Materials Science

Background:

• Covalent adaptable networks (CANs) combine thermoset robustness with thermoplastic malleability.
• Existing CANs face challenges with side reactions and performance degradation when incorporating additional functionalities.
• Achieving spatially controlled properties in CANs remains a significant hurdle.

Purpose of the Study:

• To develop and optimize locally controllable covalent adaptable networks (CANs).
• To enable on-demand tunability and shape reconfiguration in CANs.
• To overcome limitations of side reactions and performance deterioration in functionalized CANs.

Main Methods:

• Utilized base-catalyzed thiol-thioester exchange reactions for dynamic covalent chemistry.
• Employed visible light (405/450 nm) induced radical thiol-ene polymerization for network formation.
• Implemented UV-light (365 nm) activated photoacid generation to locally deactivate the dynamic exchange reaction.

Main Results:

• Successfully developed a system for locally controlled deactivation of dynamic exchange reactions in CANs.
• Investigated component interactions and factors influencing network performance.
• Demonstrated on-demand tunability, including surface and bulk shape reconfiguration via heat-assisted methods.

Conclusions:

• The presented approach enables precise, local control over CAN properties.
• Optimized CANs exhibit enhanced performance without compromising desired functionalities.
• The developed photoswitchable CANs offer significant potential for advanced material applications requiring reconfigurability.