Structure Determination of Cellulose Esters via Subsequent Functionalization and NMR Spectroscopy

New paths for the fast and reliable analysis of cellulose esters (CE) via subsequent functionalization and ¹H NMR spectroscopy were studied. Perpropionylation of the CE is an inexpensive and efficient method. For cellulose diacetates used as representative ester well resolved ¹H NMR spectra were obtained, which can be used for the calculation of the over all degree of substitution (DS) and the partial DS values at position 2, 3, and 6. No transesterification occurs during the subsequent acylation and a standard deviation of S² = 1.32 x 10⁻⁴ was found for a series of experiments. In case of more complex ester structures especially with extended aliphatic moieties per-4-nitrobenzoylation need to be applied prior to NMR measurements. The spectra obtained can be completely assigned and applied for the calculation of DS values.