Molecular characterization of hydrolyzed cationized nanocrystalline cellulose, cotton cellulose and softwood kraft pulp using high resolution 1D and 2D NMR
Journal article, 2011
Nanocrystalline cellulose, cotton linters and softwood kraft pulp were reacted with the cationic epoxide 2,3-epoxypropyltrimethyl ammonium chloride (EPTMAC) according to two different procedures, whereof one was a solvent and reagent minimizing spray technique. The samples were subjected to acid hydrolysis and characterized by solution-state nuclear magnetic resonance (NMR). The spectra were obtained using a 600 MHz cryoprobe NMR instrument. The use of ion exchange SPE-column chromatography enhanced the intensity of the peaks derived from the modified monosaccharide residues and opened for detailed NMR characterization at low degrees of substitution. In addition to a consistent 9 ppm change in the initial shifts of carbons adjacent to substituted hydroxyl groups, the NMR spectra proved that other neighboring atoms were affected by the substitution. Unlike nanocrystalline cellulose and cotton cellulose, the softwood kraft pulp cationized with the spray technique demonstrated a higher preference for 0-6 (83%), on the expense of O-2 substitution (16%).
h-1-nmr
substitution patterns
2D NMR
polysaccharides
chloride
spectroscopy
Cationization
starch
Characterization
Nanocrystalline cellulose
Softwood kraft pulp
functionalization
Cotton linters
derivatives
fiber
chemical-shifts
Author
Hanna de la Motte
Chalmers, Chemical and Biological Engineering, Organic Chemistry
Merima Hasani
Chalmers, Chemical and Biological Engineering, Organic Chemistry
Harald Brelid
Chalmers, Chemical and Biological Engineering, Forest Products and Chemical Engineering
Gunnar Westman
Chalmers, Chemical and Biological Engineering, Organic Chemistry
Carbohydrate Polymers
0144-8617 (ISSN)
Vol. 85 4 738-746Subject Categories (SSIF 2011)
Polymer Chemistry
DOI
10.1016/j.carbpol.2011.03.038