Deacetylation-induced changes in thermal properties of Sterculia urens gum

Abstract

A quantitative measurement of degree of deacetylation of Sterculia urens gum and its effect on the thermal properties changes is presented in this study. Sterculia urens gum was deacetylated at varying deacetylation reaction temperature and time. The acetyl group is replaced by hydroxyl which leads to better solubility of the sterculia gum in water. Thermal properties were characterized using differential scanning calorimetry and thermogravimetric analysis. DSC analysis reveals that after the deacetylation, the glass transition temperature appears at around 60°C of the S. urens gum. After deacetylation, the TG degradation clearly shows three different peaks. Deacetylation reaction temperature plays the major role in the thermal stability and structure of the S. urens gum.

Acute Responses of Microorganisms from Membrane Bioreactors in the Presence of NaOCl: Protective Mechanisms of Extracellular Polymeric Substances

“…The degree of acetylation due to the replacement of hydroxyl by acetyl group is characterized by 100 × A 1665 /(1.33 × A 3450 ). 31,32 Dynamic light scattering was employed to identify the changes in the hydrodynamic diameter of EPS. 33 ROS are normally generated from sequential univalent reductions of oxygen during oxidative phosphorylation, resulting in generation of ROS including superoxide anion (O 2…”

“…After reaction at predetermined durations (0, 30, 60, 90, 120 min), samples were collected and subject to combined spectroscopy analyses, i.e., three-dimensional excitation–emission matrix (EEM) fluorescence spectroscopy and Fourier transform infrared spectroscopy (FTIR). , The analytical procedures are described in SI Section S4. The degree of acetylation due to the replacement of hydroxyl by acetyl group is characterized by 100 × A 1665 /(1.33 × A 3450 ). , Dynamic light scattering was employed to identify the changes in the hydrodynamic diameter of EPS …”

Induction of defense in apples by sulfated and deacetylated chichá gum

“…The bandwidth is related to intermolecular interactions. Stronger interaction leads to a wider bandwidth [21] . The bands at 2933 and 1378 cm -1 were attributed to C-H (CH 3 ) stretching and deformation, respectively [21,22] .…”

“…Stronger interaction leads to a wider bandwidth [21] . The bands at 2933 and 1378 cm -1 were attributed to C-H (CH 3 ) stretching and deformation, respectively [21,22] . These two bands were similar for CHG and SCHG because the sulfation process does not change the number of C-H bonds in the macromolecule.…”

“…Intensification of the band at 1250 cm -1 was observed for SCHG. This absorbance is assigned to the S=O bonds of sulfate groups, and also to the acetyl group [21,23] . For this reason, this band is not present in the spectrum of DCHG.…”