Grafting of model primary amine compounds to cellulose nanowhiskers through periodate oxidation
This study demonstrates regioselective oxidation of cellulose nanowhiskers using 2.80–10.02 mmols of sodium periodate per 5 g of whiskers followed by grafting with methyl and butyl amines through a Schiff base reaction to obtain their amine derivatives in 80–90 % yield. We found a corresponding increase in carbonyl content (0.06–0.14 mmols/g) of the dialdehyde cellulose nanowhiskers with the increase in oxidant as measured by titrimetric analysis and this was further evidenced by FT-IR spectroscopy. Grafting of amine compounds to the oxidized cellulose nanowhiskers resulted in their amine derivatives, which are found to be partially soluble in DMSO. Therefore, the reduction reaction between amines and carbonyl groups was confirmed through 13C NMR spectra, which was also supported by copper titration, XPS, and FT-IR spectroscopy. Morphological integrity and crystallinity of the nanowhiskers was maintained after the chemical modification as studied by AFM and solid-state 13C NMR, respectively.
KeywordsAmine derivative Cellulose nanowhiskers Dialdehyde cellulose nanowhiskers Periodate oxidation
- Hasani M, Cranston ED, Gray DG (2009) Cationic surface functionalization of cellulose nanocrystals. Abstracts of Papers of the American Chemical Society 237Google Scholar
- Majoinen J, Walther A, McKee JR, Kontturi E, Aseyev V, Malho JM, Ruokolainen J, Ikkala O (2011) Polyelectrolyte brushes grafted from cellulose nanocrystals using Cu-mediated surface-initiated controlled radical polymerization. Biomacromolecules 12(8):2997–3006. doi:10.1021/bm200613y CrossRefGoogle Scholar
- Park S, Baker JO, Himmel ME, Parilla PA, Johnson DK (2010) Cellulose crystallinity index: measurement techniques and their impact on interpreting cellulase performance. Biotechnology for Biofuels 3. doi:10.1186/1754-6834-3-10