Carboxymethyl starch with high degree of substitution: synthesis, properties and application

Abstract

Carboxymethyl starch with high degree of substitution: synthesis, properties and application **) Summary -Highly substituted (degree of substitution, DS about 0.9) carboxymethyl starch (CMS) was prepared in isopropanol/water suspension. The influence of etherification reaction parameters on DS, reaction efficiency, number average molar mass as well as the viscosity of 2 wt. % aqueous solution was determined. Using laser scanning microscopy, X-ray diffraction and infrared spectroscopy techniques allowed to evaluate the morphological changes of modified starch granules when compared to native starch ones. An attempt to apply CMS (of high and medium DS: 0.94 and 0.39, respectively) for flocculation or dispergation tests of selected aqueous suspensions [iron(II) sulphate, iron(III) oxide, iron(III) laurate and aluminosilicates: kaolinite and calcium montmorillonite] has been performed. In case of iron(II) sulphate and iron(III) oxide high substituted CMS exhibited effective flocculating properties. Moreover, it worked as a good dispersing agent for mineral aluminosilicate suspensions.

Native and Modified Digitaria exilis Starch Nanoparticles as a Carrier System for the Controlled Release of Naproxen

“…The modified starch nanocrystal form (MSN1) showed rough surfaces with perforations/pores on their granule which is consistent with loss of crystalline structure (seen with the starch nanocrystals). The disruption of the granular structure or loss of crystalline structure of the granule may have resulted in the water solubility of the granules . Generally, carboxymethylated modified starches exhibit significantly reduced degree of crystallinity when compared to native starch …”

Water-Soluble Pressure-Sensitive Adhesives Containing Carboxymethyl Starch with Improved Adhesion to Paper

“…Preparing CMS with high degree of substitution 0.9 was carried out according to method reported elsewhere [20]. Starch was etherified in isopropanol/water as a one-step process.…”

Effect of Agitation in Alkalization Process on the Characteristics of Sodium Carboxymethyl Sago and Cassava Starches

“…As mentioned, this increase occurs due to the loss of the crystalline structure [24], which weakens the structure of starch granules so water can easily enter. The ability of starch to absorb oils shows that starch also has a lipophilic portion.…”