Synthesis, control of substitution pattern and phase transitions of 2,3-di- O-methylcellulose

An improved heterogeneous procedure has been found for the regioselective introduction of trityl and 4-methoxytrityl groups at the primary positions of cellulose. The 6- O-tritylcelluloses produced were completely methylated by MeI–NaOH in Me 2SO solution. The trityl groups were then completely remo...

Full description

Saved in:
Bibliographic Details
Published inCarbohydrate research Vol. 326; no. 1; pp. 67 - 79
Main Authors Kern, Holger, Choi, SooWhan, Wenz, Gerhard, Heinrich, Jürgen, Ehrhardt, Lutz, Mischnick, Petra, Garidel, Patrick, Blume, Alfred
Format Journal Article
LanguageEnglish
Published OXFORD Elsevier Ltd 19.05.2000
Elsevier
Subjects
Biochemistry & Molecular Biology
Cellulose
Chemistry
Chemistry, Applied
Chemistry, Organic
Degradation analysis
Life Sciences & Biomedicine
Magnetic Resonance Spectroscopy
Methylation
Methylcellulose - analogs & derivatives
Methylcellulose - chemical synthesis
Methylcellulose - chemistry
Molecular Structure
NMR
Phase Transition
Physical Sciences
Science & Technology
Stereoisomerism
Substitution pattern
Substrate Specificity
Temperature
NMR
Degradation analysis
Methylation
Substitution pattern
Cellulose
Phase transition
substitution pattern
O-METHYLCELLULOSES
cellulose
methylation
METHYL CELLULOSE
MONOMER
degradation analysis
phase transition
GELATION
THERMOGELATION
Online AccessGet full text

Cover

More Information
Summary:An improved heterogeneous procedure has been found for the regioselective introduction of trityl and 4-methoxytrityl groups at the primary positions of cellulose. The 6- O-tritylcelluloses produced were completely methylated by MeI–NaOH in Me 2SO solution. The trityl groups were then completely removed to afford 2,3-di- O-methylcellulose without significant degradation of the polymer. 1H and 13C NMR spectroscopy and degradation analysis showed less than 5% deviation from the regular substitution pattern. Under optimum reaction conditions, almost perfectly regular cellulose derivatives could be obtained. Small changes in the substitution pattern had a strong effect on the phase transitions of the O-methylcelluloses in water. It was shown by DSC for the first time that perfect 2,3-di- O-methylcellulose does not undergo phase separation at elevated temperatures.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
ISSN:0008-6215
1873-426X
DOI:10.1016/S0008-6215(00)00024-0