FT Raman investigation of sodium cellulose sulfate

Abstract

FT Raman investigation of sodium cellulose sulfates (NaCS) was reported. Different NaCS were prepared by two diverse sulfation methods and their total degrees of substitution (DS) of sulfate groups were determined through either 13 C-NMR spectroscopy or elemental analysis. Subsequently, these NaCS were characterized with FT Raman spectroscopy. The caused bands through the introduction of the sulfate groups in cellulose chain were explained and assigned. Additionally, a strong linear correlation between the areas under the bands ascribed to the stretching vibrations of C-O-S groups and the total DS of NaCS was presented. A rapid method of quantifying the total DS of NaCS was established. Finally, sodium sulfate (Na 2 SO 4 ), a salt that is very often produced during the sulfation of cellulose, was found to be analyzable even with a weight content of 0.12% in NaCS. The method of quantifying the content of this salt in NaCS was investigated with Raman spectroscopy.

Synthesis of carboxyl cellulose sulfate with various contents of regioselectively introduced sulfate and carboxyl groups

“…2 shows the Raman spectra of chosen products between 3200 and 800 cm −1 . New signals at 1274, 1072 and 830 cm −1 can be seen in CS7 in comparison to cellulose and the details about the Raman spectra of CS were already reported (Zhang, Brendler, & Fischer, 2010). After oxidation, COCS8 with a DS COO of 0.15 presents a similar spectrum as that of CS7, except for the appearance of a shoulder near the peak at 1408 cm −1 .…”

“…CS presents a cellulose II-analogue structure and this structure could be confirmed by Raman analysis (Fig. 2) (Zhang et al, 2010). CS with this cellulose II-analogue structure could exhibit a higher reactivity and accessibility of the primary hydroxyl groups than native cellulose.…”

FT Raman investigation of novel chitosan sulfates exhibiting osteogenic capacity

“…Various total DS S could be received according to Table 2. (Cabassi, Casu, & Perlin, 1978;Socrates, 2001;Zhang et al, 2010). The presence of these new bands suggests a successful introduction of sulfate groups into chitosan chains.…”

“…Raman spectroscopy can not only qualify but also quantify the polymer derivatives, such as carboxymethyl cellulose and cellulose sulfate. Characteristic vibrations derived from substituents could be used to determine the total DS attributed to these substituents (Yuen et al, 2009;Zhang et al, 2010).…”

FT Raman spectroscopic investigation of cellulose acetate

“…Raman spectroscopy, as a rapid and non-destructive method providing sensitive characterization, has been applied in characterizing cellulose and cellulose derivatives for years (Atalla 1976;Atalla et al 1980;Schenzel et al 2005;Yuen et al 2009;Zhang et al 2010). In comparison to NMR and IR spectroscopy, Raman spectroscopy has some advantages.…”