Investigation of properties of chitosan obtained by solid-phase and suspension methods

Роговина, С. З.; Акопова, Т. А.; Вихорева, Г. А.

doi:10.1002/(sici)1097-4628(19981031)70:5<927::aid-app13>3.0.co;2-q

Cited by 50 publications

(36 citation statements)

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“…Articles made of these composites can be both technical purposes, as sorbents, for examples, and in medicine as film dressings, etc. (Rogovina et al 1998;Twu et al 2003). A composite chitosancellulose membrane has been prepared by coating chitosan on filter paper (Yang et al 2002).…”

Section: Introductionmentioning

confidence: 99%

Effect of chitosan and ions on actuation behavior of cellulose–chitosan laminated films as electro-active paper actuators

2007

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Cellulose-chitosan laminated films were made for Electro-Active Paper (EAPap) actuators and the effect of chitosan and different types of free ions namely, Cl À , NO 3 À and CF 3 COO À were investigated on the actuation behavior. The fabrication process of the films was explained and the actuation performance was tested in terms of bending displacement of the actuators. It was observed that, chitosan content and type of free ions influence the tip displacement of the actuators. Cl À was found the best free ion among others, and detail observations are explained. By laminating chitosan layer on the cellulose films, the humidity sensitiveness of cellulose EAPap actuators was reduced.

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Section: Introductionmentioning

confidence: 99%

Effect of chitosan and ions on actuation behavior of cellulose–chitosan laminated films as electro-active paper actuators

2007

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“…For example, the solid-phase reaction of alkaline deacetylation of chitin and synthesis of chitosan can be successfully performed with a significantly smaller excess of sodium hydroxide for 3-5 min [65]. The interesting results were obtained upon studying the possibility of simultaneous chitin deacetylation and blending chitin, cellulose, and sodium hydroxide under joint action of high pressure and shear deformation [66].…”

Section: Solid-phase Methods Of Polysaccharide Blends Productionmentioning

confidence: 99%

Polysaccharide-based polymer blends: Methods of their production

Роговина

Вихорева

2006

Glycoconj J

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The existing methods of preparing polymer blends of cellulose, chitin and chitosan with natural and synthetic polymers and their applications are reviewed. The methods of solid-phase blending of these polymers under conditions of joint action of high pressure and shear deformation are discussed. Normally, under these conditions the processes of dispersion of polymer particles, amorphization, mixing at different levels, depolymerization as well as a chemical interaction resulting in formation of branched and crosslinked structures can take place. The probability and intensity of these processes depend in many respects on the type and magnitude of the external force, but the properties of the polymers are of higher importance. The advantages of the method of joint action of high pressure and shear deformation compared to the conventional techniques of polysaccharides mixtures production are shown.

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“…The absence of solvent and high rate of the process (3-5 min in comparison to several hours in the suspension method), the much smaller (by 2-4 times) excess of base, and correspondingly the lower consumption of water for washing make this method more efficient from an economic point of view. The solid-state process allows not only conducting deacetylation of chitin (residual degree of substitution DS for acetyl groups of 0.10-0.15) but also causes an important Acid, Glycolic, and Acetic Acids, and Mixtures (60-70%) decrease in the molecular weight of the chitosan [6,7]. The not yet realized possibilities of changing the conditions of conducting the solid-state process allow increasing the degree of deacetylation and regulating the molecular weight of chitosan in a wider range of values.…”

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confidence: 99%

Modified Fibre and Film Materials

Гальбрайх

2005

Fibre Chem

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Some results of studies on modification of polymers and polymeric materials conducted in the Department of Chemical Fibre Technology at Moscow State Textile University are examined. The promise of using the developed methods for creating materials for special applications is demonstrated: fire-retardant, chemisorption, antiadhesive, for medicine.Chemical modification is one of the most efficient methods of deliberately altering the structure, composition, and properties of fibre and film materials. Investigating the characteristics of the chemical reactions and structural mechanisms that occur in polymer systems will allow developing principles and methods for manufacturing processes for fabrication of new high-efficiency polymeric materials.Graft polymerization reactions, which alone alter the properties of polymeric materials in a direction which is a function of the type of graft monomer, occupy a special place in such systems. In particular, the results obtained in graft polymerization of such monomers as acrylonitrile, styrene, methylvinylpyridine, dimethylamino-and hydroxyethyl methacrylate, etc., are well known. At the same time, the possibilities of using reactions of this type are not limited to the direct use of graft copolymers. They have been expanded significantly due to implementation of chemical transformations of functional groups in graft chains.As the studies have shown, the approach based on graft polymerization of nonionogenic monomers containing reactive functional groups and the subsequent chemical transformations in reacting with reagents containing ionogenic groups is of great interest for solving the problem of fabricating fibre chemisorbents. A combination of small elementary fibre cross sections with localization of ionogenic groups in the surface layers, which ensure a high rate of sorption processes, is primary for materials of this type.The studies in [1-4] concerned chemical transformations of graft copolymers, where such polymers as polycaproamide, polyvinyl alcohol, cellulose, and glycidyl methacrylate modified by graft polymerization played the role of the matrix polymer. The presence of reactive oxirane (epoxide) groups in polyglycidyl methacrylate (PGMA) graft chains was grounds for using nitrogen-containing compounds of different structure (hydroxyethylamine, hydrazine and its derivatives, and many acid hydrazides) as nucleophilic reagents.The results of the studies showed that the reactivity of nitrogen-containing nucleophilic reagents is determined by many factors. They include: the diffusion characteristics of the process related to a change in the degree of swelling of the graft component and in some cases also the polymer matrix; such a change increases the diffusion coefficient of the reagent by almost a decimal order of magnitude in substitution of the solvent type (substitution of water by dimethylsulfoxide in the reaction with hydrazine hydrate); the initial reaction rate changes similarly; the change in the nucleophilicity of the reagents as a result of their reactio...

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Investigation of properties of chitosan obtained by solid-phase and suspension methods

Cited by 50 publications

References 1 publication

Effect of chitosan and ions on actuation behavior of cellulose–chitosan laminated films as electro-active paper actuators

Effect of chitosan and ions on actuation behavior of cellulose–chitosan laminated films as electro-active paper actuators

Polysaccharide-based polymer blends: Methods of their production

Modified Fibre and Film Materials

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