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Modyfikacja chitozanu : krótki przegląd

Ostrowska-Czubenko J., Pieróg M., Gierszewska M.

Wiadomości Chemiczne

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2016

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[Z] 70, 9-10

657--679

EN

Chitosan is the most important derivative of chitin, a polysaccharide found in the exoskeleton of shellfish like shrimp and crab. It is a product of deacetylation of chitin under alkaline conditions or enzymatic hydrolysis in the presence of chitin deacetylase. Both chitin and chitosan are linear polysaccharides and are chemically defined as copolymers consisting of varying amounts of β-(1→4)- linked 2-acetamido-2-deoxy β-D-glucopyranose (GlcNAc) and 2-amino-2-deoxy- β-D-glucopyranose (GlcN). The difference between chitin and chitosan lies in the content of GlcNAc and GlcN units. Chitin samples contain a high content of Glc- NAc units. Due to excellent properties of chitosan, such as biocompatibility, biodegradability, hydrophilicity, non-toxicity, cationicity, ease of modification, film forming ability, affinity to metals, protein and dyes, etc., this polymer has found applications in medicine and pharmacy, as food additive, antimicrobial agent, in paper and textile industry, in environmental remediation and other industrial areas. The presence of functional groups, reactive amino and hydroxyl groups, in chitosan backbone makes it suitable candidate for chemical modification. Chemical modification of chitosan to generate new polymers with useful physicochemical properties and distinctive biological functions is of key interest because it would not change the fundamental skeleton of the polymer. In this article the main three methods of chitosan modification: substitution reactions, reactions leading to the chain elongation and/or molecular weight increasing and methods of depolymerization are shortly characterized. Moreover, the selected methods of chitosan modification, i.e. quaternization, alkylation, acylation, carboxyalkylation, phosphorylation, sulfation, graft copolymerisation, crosslinking and depolymerization are discussed in more detail. A special attention is drawn to chitosan crosslinking with low and high molecular compounds. Chitosan modification by covalent and ionic crosslinking allows to obtain polymer materials with improved mechanical and chemical resistance and suitable for example for chitosan hydrogel membranes formation. Keywords: chitosan, chitosan modification, chitosan derivatives, crosslinking

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Equilibrium swelling behavior of crosslinked chitosan hydrogels

Ostrowska-Czubenko J., Pieróg M., Gierszewska-Drużyńska M.

Polish Journal of Applied Chemistry

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2011

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Vol. 55, nr 2

49-56

EN

Chemically and physically crosslinked chitosan hydrogels were obtained by treating chitosan (Ch) with glutaraldehyde (GA) and sodium tripolyphosphate or GA and sodium citrate, GA and sulfuric acid and GA and sulfosuccinic acid, respectively. The formation of covalent and ionic crosslinks between Ch, GA and low molecular ionic compounds was confirmed by FTIR spectroscopy. There was examined the equilibrium degree of swelling of membranes formed from uncrosslinked and crosslinked chitosan hydrogels in buffer solutions of different pH. It was observed that the swelling of all studied membranes was highly dependent on pH.

3

Efect of ionic crosslinking on chitosan membrane swelling in extracellular hanks' buffer

Gierszewska-Drużyńska M., Ostrowska-Czubenko J.

Polish Journal of Applied Chemistry

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2011

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Vol. 55, nr 1

1-9

EN

Two- and three-component chitosan membranes (Ch) crosslinked with sodium tripolyphosphate (TPP) and/or sodium alginate (NaAlg) were prepared. Formation of ionic crosslinks between Ch and high-molecular compound - NaAlg and/or low-molecular - TPP was confirmed by FTIR spectroscopy. The effcct of crosslinking agents on membrane swelling in extracellular Hanks' buffer was estimated. The obtained results allow to state, that ionic crosslinking of chitosan results in increase of membrane stability in extracellular media. However, only TPP crosslinkcd chitosan membranes are not soluble in Hanks' buffer.

4

Nieizotermiczna krystalizacja ze stopu sulfonowanego poli(tereftalanu etylenu)

Ostrowska-Gumkowska B., Ostrowska-Czubenko J.

Polimery

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2010

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T. 55, nr 9

660-667

PL

Przeanalizowano wpływ kopolimeryzacji na podstawowe parametry procesu nieizotermicznej krystalizacji ze stopu i na topnienie anionowe modyfikowanego poli(tereftalanu etylenu) (K-X/SPET), zawierającego 1,9-10,1 % mol. grup sulfonowych. W badaniach wykorzystano różnicową kalorymetrię skaningową (DSC). Wykazano istotną zależność budowy chemicznej łańcucha kopoliestru i szybkości chłodzenia stopu polimeru na przebieg procesu krystalizacji i topnienia. Wyznaczono parametry kinetyczne procesu krystalizacji metodami Khanna, Liu i współpr. oraz energię aktywacji tego procesu metodą Kissingera. Przedyskutowano wpływ stężenia grup jonowych oraz ich asocjacji na przebieg procesów krystalizacji i topnienia badanych polimerów jonowych.

EN

The influence of copolymerization on the basic parameters of the nonisothermal crystallization process from the melt (Figs. 1,4), and also on the melting behavior (Fig. 7) of anionically modified polyethylene terephthalate) (K-X/SPET, Table 1) containing 1.9 - 10.1 % mol sulfonate groups has been studied. The obtained samples were studied by differential scanning calorimetry. It was observed that the crystallization process (Figs. 2, 3, 5, 6) and melting (Fig. 7) are crucially dependent on the structure of the chemical chain of the copolyester and the cooling rate of the polymer melt. The kinetic parameters for the crystallization process were determined by the Khanna and Liu method while the activation energy for the process according to the Kissinger method. The influence of concentration of ionic groups and the association phenomenon of these groups on the crystallization process (Tables 2, 4-6) as well as the melting of the studied ionic polymers (Tables 3, 7) was discussed.

5

Synthesis and characteristics of chemically modified chitosan membranes with sulfuric acid

Ostrowska-Czubenko J., Pieróg M.

Polish Journal of Applied Chemistry

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2009

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Vol. 53, nr 2

155-160

EN

Chemically modified chitosan membranes were obtained by treatment of chitosan membranes with sulfuric acid. The effect of chemical modification conditions on molecular and supcrmolecular structure and some physicochemical properties of synthesized membranes were studied using FTIR spectroscopy, X-ray diffraction method, SEM and elemental analysis. FTIR spectra of unmodified and modified chitosan membranes were compared and conclusions concerning the formation of ionic crosslinks between protonated amine groups of chitosan and sulfate anions were drawn out. X-ray analysis indicates that strong interactions between chitosan -NH3~ groups and SO42' ions influence chitosan membrane crystallinity.

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State of water in chitosan /tripolyphosphate polyelektrolyte complex membranes for pervaportation

Gierszewska-Drużyńska M., Ostrowska-Czubenko J.

Polish Journal of Applied Chemistry

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2009

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Vol. 53, nr 1

15-21

EN

Polyelectrolyte complexes (PECs) are known as new interesting membrane materials applicable in industry, medicine and pharmacy. In this work PEC membranes from chitosan (Ch) and pentasodium tripolyphosphate (TPP) designed for pervaporation w'ere prepared by dipping Ch membranes in TPP solution. The PEC formation between Ch and TPP was confirmed by FTIR spectroscopy. Various amounts of w'ater were added into the dry ChATPP hydrogels to cause them to swell, and the amounts of water in various states were determined by the DSC ice-melting technique. Three types of water in hydrogel membranes w'ere identified: non-freezing bound water, freezing bound water, and freezing free w'ater. States of water in Ch/TPP and Ch membranes were compared and the effect of ionic crosslinking on the non-freezing water content was discussed.

7

Isothermal crystallization of sulfonated poly(ethylene terephthalate) ionomer crystal nucleation and growth parameters

Ostrowska-Gumkowska B., Ostrowska-Czubenko J.

Polish Journal of Applied Chemistry

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2009

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Vol. 53, nr 2

161-167

EN

Isothermal crystallization of a ionic random copolyster (K-X/SPET) based on poly(ethylcne terephthalate) (PET) was analysed in detail over a compositional range from pure PET to a copolymer containing 10.1 mol % of potassium neutralized sulfonated PET. In measurements differential scanning calorimetry (DSC) was used. A significant influence of the ionic groups on crystal nuclcation and growth was stated. Under isothermal conditions, the nuclcation parameters (width of a critical nuclcus and free energy of forming a critical nucleus) are slightly dependent on the co-unit content. The crystal growth in the ionic copolycsters occurs from the melt by chain folding with trc values comparable to that of the corresponding nonionic homopolymer.

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Synteza i właściwości membran hydrożelowych na podstawie chitozanu oraz alginianu sodu

Gierszewska-Drużyńska M., Ostrowska-Czubenko J.

Polimery

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2007

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T. 52, nr 7-8

517-523

PL

Badaniom poddano membrany hydrożelowe formowane z kompleksów polielektrolitowych (PEC) otrzymanych w wyniku reakcji chitozanu z alginianem sodu. Tworzenie kompleksów potwierdzono techniką FTIR. Tak zwany stan wody (state of water) w membranach o różnej całkowitej zawartości wody (Wc) scharakteryzowano z zastosowaniem metody skaningowej kalorymetrii różnicowej (DSC). Wyróżniono trzy różne typy wody w membranach hydrożelowych: wodę wolną, wodę związaną z polimerem ulegającą wymrożeniu i wodę związaną z polimerem nieulegającą wymrożeniu. Określono zawartość wody ulegającej wymrożeniu (Wf) i nieulegającej wymrożeniu (Wnf) w membranach o różnej wartości Wc oraz ciepło topnienia wody ulegającej wymrożeniu (?Hm). Na podstawie przebiegu krzywych DSC wyciągnięto wnioski dotyczące mikroheterogenicznej struktury membran formowanych z badanych PEC. Ustalono, że ciężar cząsteczkowy chitozanu wywiera niewielki tylko wpływ na stan wody w badanych membranach.

EN

Hydrogel membranes formed from polyelectrolyte complexes (PEC) obtained in the reactions of chitosan with sodium alginate (Scheme A) were investigated. The formation of complexes has been confirmed by FTIR method (Fig. 1). So called state of water in the membranes of different total water content (Wc) was characterized by differential scanning calorimetry (DSC) (Fig. 2 and 3). Three various types of water in the membranes were distinguished: free water, freezing water and non-freezing water. The contents of freezing (Wf) and non-freezing water (Wnf) in the membranes of various Wc (Fig. 5 and 6) as well as heat of fusion of freezing bound water (?Hm) (Fig. 4) were determined. The courses of DSC curves let come to the conclusions concerning microheterogenic structures of membranes formed from PEC investigated. It was found that molecular weight of chitosan very slightly influenced the state of water in the membranes tested.

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Wpływ merów jonowych na przebieg krystalizacji jonomeru polietylenotereftalanowego

Ostrowska-Gumkowska B., Ostrowska-Czubenko J., Gużyński P.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2003

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Vol. 52, nr 25

433-437

PL

Wprowadzenie nawet niewielkiej ilości merów jonowych do łańcucha głównego poli(tereftalanu etylenu), PET wywiera znaczny wpływ na właściwości fizykochemiczne tego polimeru, a w konsekwencji na zdolność do krystalizacji uzyskanego w wyniku chemicznej modyfikacji jonomeru poliestrowego. W pracy zbadano przebieg izotermicznej krystalizacji ze stopu jonomeru poliestrowego metodą różnicowej kalorymetrii skaningowej (DSC). Wykazano różnice w porównaniu do krystalizacji niemodyfikowanego PET.

EN

Overall rates of isothermal crystallisation from the melt of commercial ionic copolyester based on poly(ethylene terephthalate) (PET) were analysed in details over a composition range from pure PET to a copolymer containing 10.1 mol% of potassium-neutralised sulfonated PET. Increasing the content of -SO3K groups in the polymer chains to 4.4 mol% resulted in copolyester that was unable to crystallise. It was found that the overall rate constant, K, decreased markedly with the increasing co-unit concentration. The Avrami parameter, n, for the primary crystallisation stage varied from 2.2 to 3.8 depending on the co-unit content and the crystallisation temperature.

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Spektroskopia w podczerwieni w zastosowaniu do badania oddziaływań typu polijon - przeciwjon w polimerach w fazie skondensowanej i w roztworach

Ostrowska-Gumkowska B., Ostrowska-Czubenko J.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2001

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Vol. 50, nr 23

347-350

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Interaction of sodium and calcium ions with bioanalogous organic polyphosphates

Ostrowska-Czubenko J.

Zeszyty Naukowe. Chemia / Politechnika Śląska

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1999

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z. 140

161-164

EN

Activity coefficients of counterions in poly(alkylene phosphate) solutions containing a mixture of sodium and calcium counterions were determined by electromotive force measurements. The experimental results were compared to the theoretical predictions using Poisson-Boltzmann equation for the cylindrical cell model. It was shown, that the dependence of activity coefficients of sodium and calcium ions on the composition of counterion mixture is properly predicted by theory. However, the calculated values of the fractions of apparently free counterions noticeably exceed the measured ones.

PL

Za pomocą pomiaru siły elektromotorycznej wyznaczono współczynniki aktywności przeciwjonów sodowych i wapniowych w roztworach poli(alkilenofosforanów). Wyniki porównano z teoretycznym modelem komórki cylindrycznej opisanym równaniem Poissona-Boltzmanna.