Highly Substituted Carboxymethyl Starch

Abstract

Carboxymethyl starches (CMS) with a degree of substitution (DS) in the range of 0.5 to 1.5 and reagent yields about 70% were synthesised under heterogeneous reaction conditions. Starting from a standard procedure for manufacturing low substituted CMS the molar ratios of the reagents were increased. Under these conditions starch particles agglomerated during the reaction and the stirrer stopped. The reaction conditions (pulp density, addition of dispersing and water binding agents, pressure, sequence of reagents addition, reaction time, temperature, starch variety, etc.) were varied to find the best process conditions for optimum reaction efficiencies and product properties. If an amylose‐free starch, e.g. waxy corn starch is used as starting material, the obtained products are completely soluble in water to form a clear solution. The products are good viscosity regulators. Using a 2% aqueous solution a wide range of viscosity (1–90 000 mPa s) can be adjusted. The calcium‐binding capacity and the biodegradability of the products were investigated.

Carboxymethyl Chinese yam starch: synthesis, characterization, and influence of reaction parameters

“…Further increase in NaOH dosage caused an inactivation of MCA and hence it is consumed in the side reaction. 11 This observation is consistent with previous reports on carboxymethyl corn and amaranth starch. 12…”

Preparation and Application of Carboxymethyl Yam (Dioscorea esculenta) Starch

“…Each AGU contains three hydroxyl groups (C 2 , C 3 , and C 6 ); therefore, the DS lies between zero and three. From the studies of Volkert et al (6) and Heinze et al (7), substitution in the order C 2 >C 6 >C 3 was indicated.…”

“…Many studies have discussed the influence of reaction medium, reagent concentrations, reaction temperature, and reaction time as main factors that determine the DS of carboxymethyl starch (6,(8)(9). Some of these studies determined the effects of reaction parameters on the carboxymethylation of starch by changing one variable while keeping the others constant.…”

The Effect of Carbonation Conditions on the Properties of Carbohydrate-Calcium Carbonate Hybrid Pigments

“…However, if functional groups are introduced into the polysaccharide structure, they can form chemical bonds with minerals. For instance, Volkert et al (2004) reported that introduction of carboxyl groups into the starch markedly improved its calcium-binding capacity. In addition, the interaction of polysaccharides with minerals has been reported to be strongly dependent on pH (Liu et al 2000).…”