TY - JOUR
T1 - CPMAS 13C NMR and X-ray studies of cellooligosaccharide acetates as a model for cellulose triacetate
AU - Kono, Hiroyuki
AU - Numata, Yukari
AU - Nagai, Nobuhiro
AU - Erata, Tomoki
AU - Takai, Mitsuo
PY - 1999/11/15
Y1 - 1999/11/15
N2 - A series of crystalline oligomers from α-D-cellobiose octaacetate through α-D-cellohexaose eicosaacetate were prepared by homogeneous acetylation of the corresponding cellooligosaccharides and characterized by cross-polarization and magic angle sample spinning (CPMAS) carbon-13 nuclear magnetic resonance (13C NMR) spectroscopy and X-ray analysis to obtain the structural models of cellulose triacetate (CTA) in the solid state. Progressing toward the hexamer, the NMR spectral features of the oligomers, in comparison with two allomorphs of CTA I and CTA II, gradually approached those of CTA I. Specifically, chemical shifts of both the hexamer and pentamer were in agreement with those of CTA I. In addition, X-ray diffraction patterns of the oligomers established that the crystalline pentamer and hexamer had a CTA I lattice despite recrystallization from ethylacetate-n-hexane. Therefore, we conclude that the pentamer and hexamer are useful models for the CTA I structure.
AB - A series of crystalline oligomers from α-D-cellobiose octaacetate through α-D-cellohexaose eicosaacetate were prepared by homogeneous acetylation of the corresponding cellooligosaccharides and characterized by cross-polarization and magic angle sample spinning (CPMAS) carbon-13 nuclear magnetic resonance (13C NMR) spectroscopy and X-ray analysis to obtain the structural models of cellulose triacetate (CTA) in the solid state. Progressing toward the hexamer, the NMR spectral features of the oligomers, in comparison with two allomorphs of CTA I and CTA II, gradually approached those of CTA I. Specifically, chemical shifts of both the hexamer and pentamer were in agreement with those of CTA I. In addition, X-ray diffraction patterns of the oligomers established that the crystalline pentamer and hexamer had a CTA I lattice despite recrystallization from ethylacetate-n-hexane. Therefore, we conclude that the pentamer and hexamer are useful models for the CTA I structure.
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U2 - 10.1002/(SICI)1099-0518(19991115)37:22<4100::AID-POLA8>3.0.CO;2-D
DO - 10.1002/(SICI)1099-0518(19991115)37:22<4100::AID-POLA8>3.0.CO;2-D
M3 - Article
AN - SCOPUS:0033311864
VL - 37
SP - 4100
EP - 4107
JO - Journal of Polymer Science, Part A: Polymer Chemistry
JF - Journal of Polymer Science, Part A: Polymer Chemistry
SN - 0887-624X
IS - 22
ER -