Hydrolyzation‐Free Characterization of Acetalated Dextran via 2D Correlated Raman Spectroscopy

Abstract

This study demonstrates a hydrolysis‐free approach for characterizing acetalated dextran derivatives using Raman spectroscopy combined with two‐dimensional correlation spectroscopy (2D‐COS). Traditional methods like 1H‐NMR spectroscopy rely on hydrolysis and are constrained by the time‐sensitive detection of volatile acetone. Raman spectroscopy, as a non‐destructive technique, was applied to analyze time‐dependent acetalation of methoxy and ethoxy acetalated dextran derivatives (AcDex and AceDex). By employing 2D‐COS, time‐resolved Raman spectral changes revealed key marker bands associated with kinetic (acyclic) and thermodynamic (cyclic) substitution products. The observed Raman peak ratios corresponded well with those derived from 1H‐NMR spectroscopy, confirming the accuracy of the method. This approach not only eliminates the need for hydrolysis but also provides a robust, time‐independent tool for tracking acetalation, enabling precise control over polymer properties. The findings underscore the potential for Raman spectroscopy in real‐time monitoring and optimization of dextran‐based polymer synthesis.