Oxygen-Tolerant RAFT Polymerization Catalyzed by a Recyclable Biomimetic Mineralization Enhanced Biological Cascade...

Area of Science:

• Biocatalysis and Polymer Chemistry
• Materials Science and Nanotechnology
• Organic Synthesis

Background:

• Enzyme cascade systems offer unique catalytic properties but often lack stability and recyclability.
• Metal-organic frameworks (MOFs) provide a versatile platform for encapsulating and stabilizing enzymes.
• Developing robust and recyclable catalysts is crucial for sustainable industrial polymer synthesis.

Purpose of the Study:

• To develop a novel enzyme-MOF composite catalyst for polymerization.
• To investigate the catalytic activity and stability of the composite.
• To demonstrate the broad applicability and recyclability of the catalyst for synthesizing well-defined functional polymers.

Main Methods:

• One-step facile synthesis of a composite encapsulating glucose oxidase (GOx) and iron porphyrin (DhHP-6) within zeolitic imidazolate framework-8 (ZIF-8).
• Utilizing the GOx&DhHP-6@ZIF-8 composite to initiate oxygen-tolerant reversible addition-fragmentation chain-transfer (RAFT) polymerization of various methacrylate, acrylate, and acrylamide monomers.
• Characterization of polymer properties using proton nuclear magnetic resonance (1H NMR) and chain extension experiments.

Main Results:

• The GOx&DhHP-6@ZIF-8 composite demonstrated high monomer conversion (>85%) and narrow molar mass dispersity (<1.3) for multiple monomers.
• The composite exhibited robustness towards solvents and temperatures, maintaining catalytic activity after five recycling cycles.
• Successful synthesis of well-defined polymers with retaining end groups, indicative of living polymerization.

Conclusions:

• The developed enzyme-MOF composite catalyst is a low-cost, easily separated, and highly efficient system for synthesizing well-defined functional polymers.
• This versatile strategy is suitable for industrial-scale production, offering a sustainable alternative to traditional polymerization methods.
• The robustness and recyclability of the composite highlight its potential for broader applications in catalysis and materials science.