Starch derivatives of a high degree of functionalization. VI. Multistep carboxymethylation

Lazik, Waldemar; Heinze, Thomas; Pfeiffer, Katy; Albrecht, Geneviève; Mischnick, Petra

doi:10.1002/app.10983

Cited by 57 publications

(48 citation statements)

References 25 publications

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“…The electron withdrawing effect imposed by oxygen in the carboxymethyl substituent, C-6s (68 ppm) causes a downfield shift of~7.4 ppm compared to C-6 (61 ppm). The C-7 represents the methylene carbon atoms of the carboxymethyl group appear at three major peaks (71, 70, 69 ppm) as carboxymethyl substitution would take place in three different positions [53]. indicate the presence of amorphous cellulose [56], which could be attributed to the presence of hemicellulose and lignin as they appear amorphous in nature.…”

Section: Nmrmentioning

confidence: 99%

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

et al. 2016

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Abstract:Sago biomass is an agro-industrial waste produced in large quantities, mainly in the Asia-Pacific region and in particular South-East Asia. This work focuses on using sago biomass to obtain cellulose as the raw material, through chemical processing using acid hydrolysis, alkaline extraction, chlorination and bleaching, finally converting the material to pharmaceutical grade carboxymethyl sago cellulose (CMSC) by carboxymethylation. The cellulose was evaluated using Thermogravimetric Analysis (TGA), Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Field Emission Scanning Electronic Microscopy (FESEM). The extracted cellulose was analyzed for cellulose composition, and subsequently modified to CMSC with a degree of substitution (DS) 0.6 by typical carboxymethylation reactions. X-ray diffraction analysis indicated that the crystallinity of the sago cellulose was reduced after carboxymethylation. FTIR and NMR studies indicate that the hydroxyl groups of the cellulose fibers were etherified through carboxymethylation to produce CMSC. Further characterization of the cellulose and CMSC were performed using FESEM and DSC. The purity of CMSC was analyzed according to the American Society for Testing and Materials (ASTM) International standards. In this case, acid and alkaline treatments coupled with high-pressure defibrillation were found to be effective in depolymerization and defibrillation of the cellulose fibers. The synthesized CMSC also shows no toxicity in the cell line studies and could be exploited as a pharmaceutical excipient.

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Section: Nmrmentioning

confidence: 99%

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

et al. 2016

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“…are determined mainly by the total degree of substitution (DS). 3 However, the commercially available CMS materials often exhibit low DS up to 0.3. 4 It has found application mainly in nonfood industry: as a disintegrant and coating in pharmaceutical industry, 5 thickening and sizing agent in textile industry, 6 or colloidal agents.…”

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confidence: 99%

Carboxymethyl Starch/Montmorillonite Aqueous Dispersions: The Effect of Components and Mixing Method on Rheoviscometric Characteristics

2013

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ABSTRACT:The rheoviscometric properties of low and high substituted carboxymethyl starch (CMS) 2 wt% aqueous solutions and their dispersions with sodium, calcium, and organomodified montmorillonite (MMT) have been investigated. The influence of MMT type and content on viscosity of CMS (degree of substitution, DS, 0.90)/sodium MMT aqueous dispersions, their stability, and transparency during storage up to 18 months has been investigated. Moreover, the methods of MMT dispergation in low substituted CMS solutions (DS 0.15), that is, mechanical stirring or mechanical and ultrasonication stirring on viscosity have been compared. It resulted in higher viscosity when using the latter mixing procedure (7000 and 9250 mPa·s, respectively, at 1 rpm for CMS (DS 0.15)/7 phr calcium MMT). In addition, thermal resistance of native starch and both CMS with different DS values has been investigated. The results are important as far as commercial applications of CMS solutions or dispersions with MMTs are concerned. C

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“…As a result, the neutral starch can be turned into polyelectrolyte. The reactions such as succinylation, carboxymethylation, and etherification have been employed to introduce carboxyl groups onto starch chains [7][8][9][10]. In our lab, esterification between starch and maleic anhydride has been conducted to prepare carboxylic derivative of starch [11].…”

Section: Introductionmentioning

confidence: 99%

Tailor‐made starch‐based gels bearing highly acidic groups

Xiao

Huang

2012

Starch Stärke

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A facile synthesis route was employed to prepare starch-based hydrogels that contained highly acidic groups. The gels were obtained through the free radical cross-linking reaction between an unsaturated starch-based macromonomer and acrylic acid (AA)/sodium vinyl sulfonate or AA/itaconic acid monomer pair, and denoted as SAS or SAI. The structure of the gels was verified with FTIR, XRD, and TGA measurements. It was found that the swelling ratios of SAI and SAS depended on the feeding ratio of monomers and could be 6.6 and 12.1, respectively. Rhodamine B was bound into the gels via electrostatic interaction and able to be released again. In particular, the hydrolysis of starch was enhanced with either hydrogel. Both the encapsulation capacity for the cationic electrolyte and catalysis effect of the gels were in the order of SAS>SAI. The results indicated that the network structure and performances of the starch-based gels could be regulated by simply varying the components and ratios of monomers.

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Starch derivatives of a high degree of functionalization. VI. Multistep carboxymethylation

Cited by 57 publications

References 25 publications

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

Optimizing Extraction of Cellulose and Synthesizing Pharmaceutical Grade Carboxymethyl Sago Cellulose from Malaysian Sago Pulp

Carboxymethyl Starch/Montmorillonite Aqueous Dispersions: The Effect of Components and Mixing Method on Rheoviscometric Characteristics

Tailor‐made starch‐based gels bearing highly acidic groups

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