An experimental study on the carboxymethylation of granular potato starch in non-aqueous media

Abstract. Yam (Dioscorea esculenta) starch was modified by carboxymethylation. The effect of reaction parameters, amount of sodium hydroxide (NaOH), amount of sodium monochloroacetate (SMCA), and reaction time on the degree of substitution (DS) of carboxymethyl yam starch (CMS), was studied using the Box-Behnken experimental design. Physicochemical and potency to be a tablet disintegrant of CMS were evaluated. CMS with DS in the range of 0.08-0.19 were obtained. The results from regression analysis indicated that the most important factor in controlling DS was the amount of NaOH followed by SMCA content and reaction time. However, high concentration of NaOH and SMCA lowered the DS. The optimal conditions to achieve the highest DS (0.19) were found to be at molar ratios of NaOH and SMCA to anhydroglucose unit of 1.80 and 2.35, respectively, and with the reaction time of 4.8 h. The swelling power and viscosity of CMS increased with an increase in the degree of modification. CMS showed satisfying tablet disintegrant properties. The tablets containing 1.0-4.0 % CMS disintegrated faster than 5 min. Hence carboxymethyl yam starch can be used as an excellent tablet disintegrant in low concentration.

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“…2). A decrease in the DS was observed in other studies (4,10,19). SMCA had a positive effect on the DS, especially at high NaOH concentrations.…”

Section: Effect Of Reaction Parameters On Carboxymethylationsupporting

confidence: 68%

“…Carboxymethyl starch is a popular chemically modified starch. It is prepared by a reaction of starch (St-OH) and sodium monochloroacetate (SMCA) (ClCH 2 COO − Na + ) in the presence of sodium hydroxide (NaOH) (2)(3)(4)(5). This is a two-step reaction that proceeds as…”

Section: Introductionmentioning

confidence: 99%

Preparation and Application of Carboxymethyl Yam (Dioscorea esculenta) Starch

2009

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“…Optimal water fraction of 0.1 in isopropanol has been reported for the preparation of carboxymethyl potato starch [21].…”

Section: Effect Of Water In the Reaction Mediummentioning

confidence: 99%

“…Also, in a recent work, we reported the synthesis of CMS using water yam starch [13]. In the literature, starches from other origins have also been used for the synthesis of carboxymethyl starch and these include potato starch [21], rice starch [22], corn starch, amaranth starch [19], cassava starch [23] and mung bean starch [24]. However, the increasing demand for starch and derivatised starches in the everincreasing biopolymer based industries justifies the need for the exploration of new resources for starch, particularly cheaper alternatives to conventional sources such as potato and maize.…”

Section: Introductionmentioning

confidence: 99%

The synthesis conditions, characterizations and thermal degradation studies of an etherified starch from an unconventional source

Lawal

Lechner

Kulicke

2008

Polymer Degradation and Stability

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Starch isolated from an under-utilized legume plant (pigeon pea) was carboxymethylated.Influences of reaction parameters were investigated on the degree of substitution (DS) and the reaction efficiency (RE). Studies showed that optimal DS of 1.12 could be reached at reaction efficiency of 80.6 % in isopropanol-water reaction medium (40 o C, 3h). The scanning electron microscopy showed that after carboxymethylation, the granular appearance of the native starch was distorted. Wide-angle X-ray diffractometry revealed that crystallinity was reduced significantly after carboxymethylation. The infrared spectra revealed new bands in the carboxymethyl starch at ν =1600, 1426 and 1324 cm -1 and they were attributed to carbonyl functional groups vibration, -CH 2 scissoring and OH bending vibration respectively. Broad band 13 C NMR of carboxymethyl starch showed intense peak at δ = 180.3 ppm and it was assigned for carbonyl carbon on the carboxymethyl substituent on the AGU (Anhydroglucose Unit). DEPT (Distortionless Enhancement by Polarization Transfer) 135 NMR showed negative signals which correspond to methylene carbons on the AGU. The differential scanning calorimetry (DSC)suggests loss of crystallinity after carboxymethylation. Thermogravimetry (TG), Derivative Thermogravimetry (DTG) and Differential Thermal Analysis (DTA) show that thermal stability improved after carboxymethylation. The study provides information on the preparation and characterization of a biomaterial from a new source which could be used alone or in the preparation of other functional polymers for diverse polymer applications.2

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“…Carboxymethylation reaction (CMR) was carried out according to Williamson's ether synthesis (Pushpamalar et al 2006;Tijsen et al 2001). In brief, aqueous NaOH (30 % w/v, 10 mL) was added to a solution of isopropyl alcohol and water (80:20 v/v), followed by addition of 3 g of Lyocell fiber strands.…”

Section: Adsorbent Preparation By Carboxymethylation Reactionmentioning

confidence: 99%

Adsorptive separation of Pb(II) and Cu(II) from aqueous solutions using as-prepared carboxymethylated waste Lyocell fiber

Bediako

Kim

Wei

2016

Int. J. Environ. Sci. Technol.

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Adsorptive separation of Pb(II) and Cu(II) using modified waste Lyocell fiber adsorbent was investigated in this research. The waste Lyocell fiber was functionalized through carboxymethylation of the hydroxyl moieties using sodium chloroacetate as modifying agent and was crosslinked with epichlorohydrin to provide water stability. The maximum equilibrium batch uptake in single metal system was 353.45 mg/g for Pb(II) and 98.33 mg/g for Cu(II), according to the Langmuir isotherm model. The adsorption rates were very fast and reached equilibrium within 3 and 5-10 min for Cu(II) and Pb(II), respectively. In competitive binary metal system, the uptake of Cu(II) largely decreased to 38.40 mg/g, and Pb(II) selectivity was observed. Elemental and functional characterization suggested that the adsorption proceeded by ion exchange between the adsorbent and metal ions. In a flow-through column system, adsorption followed by desorption aided in effectively eluting *260 mg of Pb(II) (out of *300 mg total adsorbed) from the Pb(II)-Cu(II) binary solution. Finally, the adsorbent was very effective in four successive adsorption-desorption cycles with over 99 % uptake and 94 % desorption efficiencies. The present study may provide an alternative option for waste fiber recycling and could be useful in recovering heavy metal ions from aqueous sources to complement their depleting reserves.

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An experimental study on the carboxymethylation of granular potato starch in non-aqueous media

Cited by 110 publications

References 15 publications

Preparation and Application of Carboxymethyl Yam (Dioscorea esculenta) Starch

Preparation and Application of Carboxymethyl Yam (Dioscorea esculenta) Starch

The synthesis conditions, characterizations and thermal degradation studies of an etherified starch from an unconventional source

Adsorptive separation of Pb(II) and Cu(II) from aqueous solutions using as-prepared carboxymethylated waste Lyocell fiber

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