Switching from Controlled Ring-Opening Polymerization (cROP) to Controlled Ring-Closing Depolymerization (cRCDP) by...

Area of Science:

• Polymer Chemistry
• Materials Science

Background:

• Controlling polymer-monomer equilibrium is crucial for advanced material applications.
• Reversible polymerization-depolymerization cycles offer new possibilities for polymer synthesis and degradation.

Purpose of the Study:

• To investigate the selective transition between monomeric and polymeric states using ceiling temperature (Tc).
• To explore the ring-closing depolymerization (RCDP) mechanism and its relation to polymerization.
• To understand the influence of solvent on the ceiling temperature and polymerization behavior.

Main Methods:

• Utilized controlled ceiling temperature (Tc) to switch between ring-opening polymerization and ring-closing depolymerization.
• Studied the monomer 2-allyloxymethyl-2-ethyl-trimethylene carbonate (AOMEC) and its polymer poly(AOMEC).
• Investigated solvent effects on Tc using toluene and acetonitrile.

Main Results:

• Achieved reversible monomer-polymer conversion within 10 hours by manipulating Tc relative to reaction temperature (T0).
• Demonstrated that RCDP occurs at the chain end, with polymer molecular weight dependent on monomer concentration.
• Showcased significant solvent dependency of Tc, with values differing by over 90°C between toluene and acetonitrile.

Conclusions:

• Precise control over monomer-polymer equilibrium via Tc enables selective polymer degradation and controlled release.
• The findings are critical for in vivo applications requiring polymers to adapt to diverse environmental conditions.
• This work establishes new standards for monomer synthesis, material recycling, and polymer lifecycle management.