Application of the solvent dimethyl sulfoxide/tetrabutyl-ammonium fluoride trihydrate as reaction medium for the homogeneous acylation of Sisal cellulose

Two types of Sisal cellulose were studied as starting material for homogeneous acylation in the solvent dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride trihydrate (TBAF). The native Sisal cellulose investigated contains 14% hemicellulose (mainly composed of xylose) as confirmed by 13C-NMR spec...

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Bibliographic Details
Published inCellulose (London) Vol. 10; no. 2; pp. 125 - 132
Main Authors Ciacco, Gabriela T, Liebert, Tim F, Frollini, Elisabete, Heinze, Thomas J
Format Journal Article
LanguageEnglish
Published Dordrecht Springer Nature B.V 01.06.2003
Subjects
Acidic oxides
Acylation
Anhydrides
Cellulose
Chemical industry
Degree of polymerization
Dimethyl sulfoxide
Esters
Fluorides
High temperature
NMR spectroscopy
Solvents
Strong interactions (field theory)
Sulfoxides
Xylose
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Summary:Two types of Sisal cellulose were studied as starting material for homogeneous acylation in the solvent dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride trihydrate (TBAF). The native Sisal cellulose investigated contains 14% hemicellulose (mainly composed of xylose) as confirmed by 13C-NMR spectroscopy in DMSO-d6/TBAF and HPLC analysis after complete polymer degradation. Alkali treatment of Sisal cellulose decreases the amount of hemicellulose, the degree of polymerization and the crystallinity. Both Sisal cellulose samples can be dissolved in DMSO/TBAF after treatment at elevated temperature. GPC measurements showed high aggregation in the solution. Different homogeneous acylation reactions using carboxylic acid anhydrides and vinyl esters were carried out, showing a pronounced tendency of the anhydride towards hydrolysis in the solvent. This disadvantage can be diminished by decreasing the amount of the salt hydrate (TBAF trihydrate) or by a distillative removal of the majority of water. A strong interaction of the polymer with the water in the solvent was observed.
ISSN:0969-0239
1572-882X
DOI:10.1023/A:1024064018664