Protonation constants of chitosan with different molecular weight and degree of deacetylation

Wang, Qi Zhao; Chen, Xi Guang; Liu, Nan; Wang, Shi Xi; Liu, Chengsheng; Meng, Xiong; Liu, Chen‐Guang

doi:10.1016/j.carbpol.2006.01.001

Cited by 359 publications

(175 citation statements)

References 21 publications

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“…Molecular weight determination For the determination of viscosity-average molecular weight, eight chitosan solutions at different concentrations were prepared in 0.2 M NaCl/0.1 M AcOH. The solvent was chosen according to the deacetylation degree results from the study of Wang et al (2006). The efflux times of the solutions were measured in triplicate using an Ubbelohde capillary viscometer in a constant-temperature water bath at 25°C.…”

Section: Elemental Analysismentioning

confidence: 99%

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Physicochemical characterization of chitosan extracted from Metapenaeus stebbingi shells

et al. 2011

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a b s t r a c tIn this study, chitosan was extracted from Metapenaeus stebbingi shells. In order to determine physicochemical characteristics of the extracted chitosan, the yield, moisture and ash contents, degree of deacetylation, molecular weight, water and fat binding capacities, apparent viscosity and colour properties were measured using a variety of techniques including Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. In addition, the physicochemical characteristics of the chitosan extracted from M. stebbingi shells were compared to commercial chitosan. The degree of deacetylation was calculated by the titration method and elemental analysis. The molecular weight was determined by viscosimetric methods. The results of the study indicate that shrimp shells are a rich source of chitosan as 17.48% of the shell's dry weight is consisted of this material. Extracted chitosan exhibited a lower molecular weight, higher degree of deacetylation, higher viscosity and higher water and fat binding capacities compared to the commercial chitosan.

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Section: Elemental Analysismentioning

confidence: 99%

“…M is relative molecular weight. Values of K and a were 1.64 Â 10 À30 Â DD 14 (ml/g) and 1.02 Â 10 À2 Â DD + 1.82, respectively, and DD is the degree of deacetylation of chitosan expressed as the percentage (Wang et al, 2006).…”

Section: Elemental Analysismentioning

confidence: 99%

Physicochemical characterization of chitosan extracted from Metapenaeus stebbingi shells

et al. 2011

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“…Furthermore, only certain acids are capable of solubilizing the polymer, such as the acid primarily utilized in this study, acetic acid. The ammonium cation on the polymer backbone has a pKa of approximately 6.5, 13,14 indicating that in solutions of acetic acid, which has a pKa of 4.76, the amine is protonated and has a formal positive charge. The ionization of the amine renders chitosan a polyelectrolyte, making it a feasible material for applications in biofuel cells and biosensors as a conducting membrane or scaffold.…”

Section: General Overviewmentioning

confidence: 99%

Controlled Deposition of Structured Polymer Films: Chemical and Rheological Factors in Chitosan Film Formation

et al. 2012

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The technique of spread-coating was utilized to create thin films of chitosan polymer. The effect of deposition rate on film thickness was characterized for solutions of deacetylated and butyl-modified chitosan. For the range of deposition rates analyzed, the relationship between film thickness and increasing deposition rate fell into three distinct regions: an initial inverse relationship, a second linearly increasing relationship, and a final region wherein the film thickness remained constant. Results suggest that film thickness was both controllable and reproducible and that hydrophobic modification of the polymer extends the range over which a linear relationship between film thickness and deposition rate is achieved.Viscometry and fluorescence spectroscopy were employed to characterize the micellar characteristics of solutions of both deacetylated and butyl-modified chitosan.Deacetylated chitosan solutions possessed more interconnected hydrophobic domains that had more intermolecular micellar characteristics, while butyl-modified chitosan solutions had more intramolecular micellar characteristics and less interconnected hydrophobic domains.

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“…It is a deacetylated product of chitin which is a major component of the shells of crustaceans such as shrimps and crabs [3]. Chitosan has limited solubility, high biodegradability and it is non-toxic [4].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Callinectes Chitosan as a Superdisintegrant in Metronidazole Tablet

Olorunsola

Adedokun

Akpabio

2017

Int J Pharm Pharm Sci

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Objective: The objective of this study is to evaluate callinectes chitosan as a superdisintegrant in tablet formulation; superdisintegrants are incorporated into tablets at concentrations below 5% of tablet weight to effect prompt break-up of tablets after administration. Methods:Chitosan was extracted from shells of Callinectes gladiator. The polymer was characterized and then used as a disintegrant (in comparison with Ac-Di-Sol ® and corn starch) at concentrations of 2, 4 and 8% for the formulation of metronidazole tablets. The micromeritic properties of granules; and mechanical and release properties of the tablets were studied.Results: A yield of 36.7% chitosan having degree of deacetylation of 62.7% was obtained from the crab shell. Fourier Transform Infrared absorption bands at 1495 and 3240 cm -1 typical of N-H bending and stretching respectively; and endothermic peak of 159 °C typical of melting of chitosan were obtained. No adverse interaction between the chitosan and metronidazole was observed. The disintegration times of tablets containing 2, 4 and 8% chitosan were 12.2, 10.4 and 9.3 min respectively. Conclusion:Callinectes chitosan is suitable for use as a superdisintegrant in tablets. It appears to be superior to corn starch as disintegrant although less effective compared to Ac-Di-Sol ® . However, the relative cheapness and ready availability of chitosan would make it to be preferred to Ac-Di-Sol ® .

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Protonation constants of chitosan with different molecular weight and degree of deacetylation

Cited by 359 publications

References 21 publications

Physicochemical characterization of chitosan extracted from Metapenaeus stebbingi shells

Physicochemical characterization of chitosan extracted from Metapenaeus stebbingi shells

Controlled Deposition of Structured Polymer Films: Chemical and Rheological Factors in Chitosan Film Formation

Evaluation of Callinectes Chitosan as a Superdisintegrant in Metronidazole Tablet

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