Acid-catalyzed Disulfide-mediated Reversible Polymerization for Recyclable Dynamic Covalent Materials

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Chemistry

Background:

• Poly(1,2-dithiolane)s are known for their recyclability due to dynamic disulfide bonds.
• Thiolate-initiated anionic ring-opening polymerization (ROP) is common, but cationic ROP remains underexplored.

Purpose of the Study:

• To explore the potential of cationic ROP for synthesizing poly(disulfide)s.
• To develop an efficient and recyclable polymerization method for 1,2-dithiolanes.

Main Methods:

• Disulfide bonds were protonated by acids to form initiating sulfonium cations.
• Ring-opening polymerization (ROP) of 1,2-dithiolanes was initiated under acidic conditions.
• Catalytic amounts of acids and non-coordinating anion salts were used.

Main Results:

• High-molecular-weight poly(disulfide)s (over 1000 kDa) were synthesized.
• The reaction proceeded rapidly (minutes) at room temperature under open-air conditions.
• Nearly quantitative chemical recycling from bulk materials to monomers was achieved.

Conclusions:

• Acid-initiated cationic ROP provides an efficient route to poly(disulfide)s.
• The method is compatible with acidic monomers and allows for facile recycling.
• This approach offers a practical and sustainable method for polymer synthesis and recovery.