Enzymatic polymerization to polyesters in nonaqueous solvents.

Area of Science:

• Polymer Chemistry
• Green Chemistry
• Biotechnology

Background:

• Aliphatic polyesters, including polylactides (PLAs), are biodegradable and renewable alternatives to petrochemical-based polymers.
• Enzymatic polymerization presents a more environmentally benign synthesis method compared to traditional chemical routes.
• Reaction conditions such as solvent type, water content, and temperature significantly influence enzymatic polyester synthesis outcomes.

Purpose of the Study:

• To explore various solvent systems for enzymatic polymerization of polyesters.
• To evaluate the impact of different solvents on enzymatic polymerization efficiency and resulting polymer properties.
• To discuss the advantages and challenges of using organic solvents, supercritical fluids, and ionic liquids in enzymatic polyester synthesis.

Main Methods:

• Illustrates examples of enzymatic polymerization reactions for polyester synthesis.
• Investigates the use of diverse solvent systems: organic solvents, supercritical fluids (e.g., scCO2), ionic liquids, and aqueous biphasic systems.
• Analyzes the influence of solvent hydrophobicity and water content on polymerization kinetics and molecular mass.

Main Results:

• Hydrophobic solvents with low water content generally promote enzymatic polymerization, yielding high molecular mass polyesters.
• High-temperature reactions necessitate solvents with high boiling points, such as certain ionic liquids.
• Supercritical CO2 offers a green solvent option but faces challenges in enzyme compatibility and scalability.

Conclusions:

• Enzymatic polymerization is a viable green approach for producing biodegradable polyesters.
• Solvent selection is critical for optimizing enzymatic polymerization, with hydrophobic solvents favoring higher molecular weights.
• Ionic liquids show promise due to their tunable properties and thermal stability, though further research is needed for polycondensation and ROP applications.