ALPHA-D-CELLOOLIGOSACCHARIDE ACETATES - PHYSICAL AND SPECTROSCOPIC CHARACTERIZATION AND EVALUATION AS MODELS FOR CELLULOSE TRIACETATE

The series of crystalline oligomers from α-D-cellobiose octaacetate through α-D-cellononaose nonacosaacetate was prepared and characterized by mass spectrometry, by 1H and 13C NMR spectroscopy, and by differential scanning calorimetry. Through extrapolation of these values to cellulose triacetate (CTA), the resulting data are discussed in terms of the critical degree of polymerization (DP). Carbon-13 spinlattice relaxation values (T1) indicate a critical DP of 7; it is predicted that the Tm and Hf of CTA should be 294 °C and 4.9 kcal/mol. These values are discussed in relation to experimental values for CTA Complete 1H and 13C NMR assignments and a protocol for obtaining useful mass spectra via positive-ion liquid secondary ion mass spectrometry (LSIMS) for cellooligosaccharide acetates are provided. © 1990, American Chemical Society. All rights reserved.