Enzymatic Synthesis of Hydroxy-Functionalized Glycerol-Based Polyesters: A Study of Functionalization, Regioselectivity Control, and Catalyst Reuse

Obtaining polyesters with the preservation of pendant hydroxyl groups is desired because it allows for the modulation of degradability and hydrophilicity for later functionalizations and applications, including encapsulation and construction of micropatterned elastomers, scaffolds, and fibrous structures by electrospinning or 3D printing. The catalytic specificity of N435 for synthesizing poly(propylene succinate-co-glycerol succinate) (PPSG) with varying comonomer ratios has been explored. Characterization of the polymers involved evaluation of the molecular architecture, average molar masses, hydrophilicity, and rheological behavior. Various techniques were employed, including nuclear magnetic resonance, Fourier transform infrared, gel permeation chromatography, goniometry, rheometry, scanning electron microscopy, and enzymatic activity analysis. Polymer architecture was affected by glycerol fractions, leading to different gel contents. Using 10 wt % of the N435 and a 20% molar ratio of glycerol, a PPSG with higher hydrophilicity and low gel content was obtained. Enzyme reuse was studied, and insights into the polyester-enzyme support interaction were gained. Ultimately, the potential of glycerol-based polyesters to expand the range of hydroxy-functionalized materials for advanced applications has been enhanced.