Lipase-Driven Synthesis of Poly(ethylene succinate) in Deep Eutectic Solvents: Enhanced Polymerization Degree and Mechanical Reinforcement for Multifunctional Textiles

This study developed an efficient and environmentally friendly method for the synthesis of poly(ethylene glycol) succinate (PES) using a lipase-catalyzed transesterification reaction with deep eutectic solvent (DES) as a green medium. The synthesized PES has three structures: ester–alcohol end group (nae), alcohol–alcohol end group (naa), and ester–ester end group (nee). By screening various DES formulations, decanoic acid-lidocaine (DA:Lid) with a molar ratio of 2:1 in a volume of 2 mL was identified as the best solvent. Its low viscosity, low surface tension, lower polarity, and moderate hydrogen-bonding network significantly maintained lipase conformational stabilization activity and increased the average degree of polymerization of PES (nae = 3.78). Applying the PES synthesis method to cotton fabrics, the surface morphology of cotton fabrics became roughened by in situ synthesized PES, forming a PES coating that imparted hydrophobicity and enhanced thermal stability. The interfacial binding mechanism between PES and the substrate was elucidated by infrared spectral analysis of the fabrics. This study provides a sustainable and multifunctional approach to polyester synthesis and textile functionalization and promotes green chemistry through the development of functional materials with tailored properties.