FT Raman spectroscopic investigation of cellulose acetate

Abstract

This study reports on a new method characterizing cellulose acetates and determining the contents of acetyl groups within cellulose acetates based on FT Raman spectroscopy. Cellulose acetates exhibiting diverse degrees of substitution ascribed to acetyl groups (DS Ac ) were obtained after the deacetylation of highly acetylated cellulose, i.e. cellulose diacetate and cellulose triacetate (CTA), with aqueous sodium hydroxide solution or 1,6-hexamethylenediamine (HMDA). After plotting the Raman intensity ratios between the bands at 1,740 and 1,380 cm -1 against the DS Ac , a calibration curve with high correlation coefficient of more than 0.99 was obtained. During the deacetylation of highly acetylated cellulose, a by-product-sodium acetate (NaOAc)-forms as the most possible salt among others. In order to determine the content of NaOAc, the mixtures of cellulose acetates and NaOAc were measured with FT Raman spectroscopy. Based on the relationship between the Raman intensity ratios as I 929 /I 1380 and the contents of NaOAc in the mixtures, a calibration curve exhibiting high correlation coefficient of more than 0.99 was generated.

Dynamical study of the water penetration process into a cellulose acetate film studied by coherent anti-Stokes Raman scattering (CARS) microspectroscopy

“…As discussed, the water content was 2.4% in the atmospheric condition, Figure 1 shows Im[ (3) ] spectrum of a CA film in the fingerprint region. The result agrees well with the reported Raman spectrum of CA [26][27][28][29][30][31]. The assignment is listed in Table 1.…”

Per-O-acylation of xylan at room temperature in dimethylsulfoxide/N-methylimidazole

“…According to previous studies, FT-IR spectra can provide an alternative method for calculating the DS (Samios et al 1997;Zhang et al 2011a;Chen et al 2014). In the present study, a typical example of the detailed relationship between the DS of XyPa and the ratio of the hydroxyl peak (3479 cm -1 ) height to the carbonyl peak (1752 cm -1 ) area is presented in Table 2.…”

A facile and rapid sonochemical synthesis of monodispersed Fe3O4@cellulose nanocrystal nanocomposites without inert gas protection

“…This indicated that the CNC remained its crystalline nature after the reaction between its surface hydroxyl groups and the Fe 3 O 4 . To support that, various findings showed that the peak at 380 cm −1 vanished completely when the CNCs turned amorphous . The enhanced effect of oxidative resistance of Fe 3 O 4 was mainly attributed to the potential antioxidant utilization activity of CNC fibre .…”

“…Raman spectra had been obtained for pure MNP, CNC, and MCNC composites, and the results were presented in Figure c (i) to (iv). The characteristics peaks of pure crystalline CNC were located at 380 cm −1 (C–C–O or C–O), 898 cm −1 (C–OH bonding), and 1,098 and 1,120 cm −1 (C–O–C stretching and bending) whereas MNPs displayed the characteristic peak of Fe 3 O 4 at around 670 cm −1 . The Raman spectral patterns of MCNC composites synthesized with and without N 2 environment were found to be highly similar.…”