Intrinsically Re-curable Photopolymers Containing Dynamic Thiol-Michael Bonds

Area of Science:

• Polymer Chemistry
• Materials Science
• Sustainable Chemistry

Background:

• Developing photopolymers with reversible properties is challenging.
• Existing photopolymers often lack recyclability or require harsh conditions for depolymerization.

Purpose of the Study:

• To create a photopolymer platform that is re-curable using the same light stimulus.
• To utilize a bio-sourced feedstock for sustainable polymer development.
• To achieve thermally driven depolymerization of mechanically robust polymer networks.

Main Methods:

• Synthesized a photopolymer using bio-sourced l-carvone and a multi-arm thiol.
• Utilized orthogonal reactivity: irreversible thioether and dynamic thiol-Michael bonds.
• Achieved photopolymerization via UV exposure and depolymerization via thermal activation of Michael bonds.

Main Results:

• Created a mechanically robust, re-curable photopolymer network.
• Demonstrated successful depolymerization and regeneration of the photopolymer over two cycles.
• Maintained excellent thermomechanical properties, including insolubility and high thermal stability (up to 170 °C).

Conclusions:

• Developed an on-demand, re-curable photopolymer platform based on sustainable l-carvone.
• The orthogonal reactivity strategy enables efficient photopolymerization and thermally triggered depolymerization.
• This approach offers a sustainable alternative to conventional photopolymers with enhanced recyclability.