Photoswitchable olefins as latent metathesis monomers for controlled polymerization

Area of Science:

• Polymer Chemistry
• Materials Science
• Catalysis

Background:

• Polymer science has transformed society, yet advanced material development requires improved control over polymerization.
• Current methods often focus on catalyst control, with room for alternative strategies.

Purpose of the Study:

• To introduce a novel monomer-centered approach for spatiotemporal control in polymerization.
• To utilize quadricyclane-norbornadiene isomerization as a switchable monomer for ring-opening metathesis polymerization (ROMP).

Main Methods:

• Developed four norbornadiene derivatives utilizing quadricyclane-norbornadiene isomerization.
• Employed ruthenium-based olefin metathesis initiators for polymerization.
• Investigated thermal and photothermal (gold bipyramids) activation methods.

Main Results:

• Achieved on-demand polymerization of norbornadiene derivatives with high efficiency.
• Demonstrated remarkable stability of latent monomer formulations (up to 7 weeks).
• Enabled 3D printing applications and developed a one-pot diblock copolymerization strategy.

Conclusions:

• The quadricyclane-norbornadiene system offers a robust, switchable monomer alternative for ROMP.
• This approach provides unprecedented control over polymerization, enabling advanced material synthesis and processing.
• The developed methodology opens new avenues for creating complex polymer architectures and functional materials.