Cellulose samples treated with sodium hydroxide (NaOH) and carbon dioxide in dimethylacetamide (DMAc) were analyzed by FTIR spectroscopy. Absorbance of hydrogen-bonded OH stretching was considerably decreased by the treatment of NaOH and carbon dioxide. The relative absorbance ratio ( A 4000–2995/ A 993) represented the decrease of absorbance as a criterion of hydrogen-bond intensity (HBI). The absorbance of the band at 1430 cm −1 due to a crystalline absorption was also decreased by NaOH treatment. The absorbance ratio of the bands at 1430 and 987–893 cm −1 ( A 1430/ A 900), adopted as crystallinity index (CI), was closely related to the portion of cellulose I structure. With the help of FTIR equipped with an on-line evacuation apparatus, broad OH bending due to bound water could be eliminated. FTIR spectra of the carbon dioxide-treated cellulose samples at 1700–1525 cm −1 were divided into some bands including 1663, 1635, 1616, and 1593 cm −1. The broad OH bending due to bound water at 1641–1645 cm −1 was resolved to two bands at 1663 and 1635 cm −1. As a trace of DMAc, the band at 1616 cm −1 is disappeared by washing for the cellulose treated with carbon dioxide (Cell 1-C and Cell 2/60-C). The decrease of HBI, the easy removal of DMAc, and the band at 1593 cm −1 supported the introduction of new chemical structure in cellulose. The bands shown at 1593 and 1470 cm −1 was assigned as hydrogen-bonded carbonyl stretching and O–C–O stretching of the carbonate ion.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call