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1
Content available VISCOMETRIC STUDIES OF MICROCRYSTALLINE CHITOSAN/POLY(VINYL ALCOHOL) MIXTURES
100%
Lewandowska K.
Progress on Chemistry and Application of Chitin and its Derivatives
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2011
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tom 16
43 - 48
EN
In the present paper, the results of viscosity measurements in dilute solutions of microcrystalline chitosan (MCCh) with poly(vinyl alcohol) (PVA) of different degrees of hydrolysis are presented. Microcrystalline chitosan is blended with poly(vinyl alcohol) in aqueous 0.1 MCH3COOH/0.2 M NaCl. Viscosity measurements of dilute polymer solution were carried out in an Ubbelohde capillary viscometer. The final result depends on (I) the thermodynamic goodness of the solvent, on (II) the applied extrapolation method used for determination of the interaction parameters, on (III) the assumed miscibility criteria, on (IV) the degree of hydrolysis of PVA, and on (V) the blend composition.
2
Content available BIOPOLYMER COMPOSITES BASED ON LIGNIN AND MICROCRYSTALLINE CHITOSAN
88%
Kopania E. , Wiśniewska-Wrona M.
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2016
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tom 21
122-134
EN
The article presents method of extracting lignin from hardwood and softwood after chemical treatment. Lignin fractions were extracted from black liquid (the by-product of pulp and paper industry), in a different reaction environment. Biopolymer composites were obtained by combining extracted lignin fraction and microcrystalline chitosan, which can be used as preparations for innovative biopolymer materials that are applicable in medical and hygienic products. The studies were performed in order to evaluate MCCh/Lignin composites to suitability to construction of dressing materials in the form of sponges. The MCCh/Lignin composites were tested for different properties: mechanical, sorption and absorption. The obtained lignin fractions and MCCh/Lignin composites were characterized by different structures and chemical purity as confirmed by FTIR spectra.
3
Content available THERMAL AND ATOMIC FORCE MICROSCOPY (AFM) STUDIES OF MICROCRYSTALLINE CHITOSAN/POLY(VINYL ALCOHOL) MIXTURES
88%
Lewandowska K.
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2010
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tom 15
11 - 16
EN
In the present paper, the results of thermal analysis (DSC and TGA) and atomic force microscopy studies of microcrystalline chitosan (MCCh) with poly(vinyl alcohol) (PVA) are presented. Microcrystalline chitosan is blended with poly(vinyl alcohol) in acetic acid solution and this solution is cast to prepare the blend film. From thermal curves the thermal transitions: Tg, Tm and characteristic temperatures of decomposition: Tdi, Tmax have been determined and compared. The influence of the degree of PVA hydrolysis on the thermal properties of blend systems has been discussed. The surface properties of the MCCh and PVA films and their blends have been studied by tapping-mode atomic force microscopy (AFM). The changes of topography images were considered by determining the root mean square (RMS) deviation in the image data. The obtained results suggested that in solid MCCh/PVA mixtures the components are poorly miscible.
4
Content available BIOPOLYMER COMPOSITES BASED ON GALACTOGLUCOMANNANS (GGMS) AND MICRYSTALINE CHITOSAN (MCCH)
75%
Kopania E. , Wiśniewska-Wrona M.
Progress on Chemistry and Application of Chitin and its Derivatives
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2015
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tom 20
110-121
EN
The article presents a method of extracting galactoglucomannas (GGMs) from softwood (spruce). GGMs were extracted using thermal and enzymatic treatment in an aqueous environment. The extracted GGMs, depending on the extraction method, were characterized by different composition of simple carbohydrates i.e. glucose, galactose and mannose, as well as by the average molecular weight. Evaluation of the composition of GGMs obtained was performed using GC/MS and SEC. Biopolymer composites were obtained by combining GGMs and microcrystalline chitosan (MCCh), which can be used as preparations for plant protection and growth stimulation. The studies were performed in order to evaluate biological activity of composites based on Petri dish test in which their ability to stimulate seed germination of selected plants was estimated. The effect of plant growth stimulation depended on GGMs composition of simple carbohydrates. GC/MS and SEC chromatographic tests and 13C NMR analysis enabled to establish the composition and structural changes of the obtained GGMs and biocomposites
5
Content available remote Study on the stability of microcrystalline chitosan systems with selected non-steroidal anti-inflammatory drugs
51%
Bodek K. H.
Polimery
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2004
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tom T. 49, nr 1
29-35
EN
The stabilities of microcrystalline chitosan (MCCh) systems with selected non-steroidal anti-inflammatory drugs (NSAIDs) were investigated after storage at ambient temperature for 12 months or at 60 and 80 °C for 5 h. Diclofenac (DA) and ketoprofen (KTA) in free acid form were used as model drugs in this study. For both the MCCh-drug (DA, KTA) systems, the intensity of bands corresponding to chitosan and drug slightly decreased as the temperature increased. X-ray diffraction and differential scanning calorimetry (DSC) showed that KTA in the microcrystalline chitosan systems remained in the amorphous state in contrary to DA, which was present in crystalline state. The interactions between DA and MCCh are not as strong and develop with time. The interaction between KTA and polymer (decrease in drug crystallnity) in stored systems is similar to those in freshly prepared samples. The amorphic form of KTA is present throughout the whole storage time. Slight decrease in KTA release rate was observed for MCCh film stored at 80 °C. These results suggest that microcrystalline chitosan is a suitable carrier for drugs of different solubility.
PL
Zbadano interakcję nośnika polimerowego [zawierającego grupy aminowe mikrokrystalicznego chitozanu, MCCh, wzór (I)] z niesteroidowymi substancjami przeciwzapalnyrni [diklofenakiem, DA, wzór (II) i ketoprofenem, KTA, wzór (III)], wybranymi jako modelowe substancje lecznicze o charakterze kwasu. Celem pracy było określenie wpływu czasu przechowywania, temperatury i charakteru oddziaływania tego nośnika z lekiem na szybkość uwalniania substancji leczniczej z MCCh (rys. 5). Charakter wspomnianego oddziaływania oceniano metodami IR (rys. 1 i 2), DSC (rys. 3) oraz rentgenograficzną (rys. 4). Uzyskane wyniki świadczą o tym, że specyficzne oddziaływania pomiędzy lekiem o charakterze kwasu i polimerem zawierającym wolne grupy aminowe prowadzą do tworzenia trwałych połączeń, charakteryzujących się lepszą rozpuszczalnością. Czas przechowywania i temperatura nie wpływają w istotny sposób na ilość uwolnionego KTA z układu z MCCh, aczkolwiek nośnik ten zmienia pierwotną strukturę krystaliczną KTA na amorficzną, która jest obecna przez cały czas przechowywania. Natomiast w przypadku DA o znacznie mniejszej rozpuszczalności w wodzie stwierdzono poprawę uwalniania (rozpuszczalności) dopiero pod wpły-wem przechowywania, chociaż przechowywanie tylko nieznacznie zmienia krystaliczność DA. Można stwierdzić, że w tym przypadku oddziaływania pomiędzy polimerem i lekiem nie są mocne i zależą od czasu przechowywania. Mikrokrystaliczna odmiana chitozanu ze względu na specyficzny charakter interakcji z niesteroidowymi substancjami przeciwzapalnymi jest więc korzystnym nośnikiem.
6
Content available remote Studies on the Biodegradation of Microcrystalline Chitosan in Aqueous Medium
51%
Ratajska M. , Wiśniewska-Wrona M. , Strobin G. , Struszczyk H. , Boryniec S. , Ciechańska D.
Fibres & Textiles in Eastern Europe
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2003
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tom Vol. 11, no. 1 (40)
59--63
EN
Microcrystalline chitosan (MCCh), obtained from standard chitosan of shrimp-shell origin in film form and a lyophilisate, was subjected to biodegradation in an aqueous medium. The aim of the investigation was to determine the effect of the form of the material, the time and the temperature of biodegradation on its course. The estimation of the biodecomposition degree was carried out by applying such methods as gravimetry - weight loss investigations, gel permeation chromatography (GPC) - changes in molecular structure, and FTIR -spectrophotometry. The results obtained lead to the conclusion that MCCh is a polymer which easily undergoes biodegradation. Within the range of the temperatures used in tests the best results were received at 40°C.
PL
Badaniom poddano chitozan mikrokrystaliczny w formie folii i liofilizatu, wytworzony z chitozanu standardowego, pochodzącego z krewetek. Celem badań było określenie wpływu postaci preparatu, czasu i temperatury biodegradacji na jej przebieg. Ocena procesu dekompozycji prowadzona była takimi metodami jak: grawimetria - ubytek masy preparatu, chromatografia żelowa (GPC) - zmiany struktury molekularnej i spektrofotometria FTIR - zmiany stopnia deacetylacji. Uzyskane wyniki pozwalają stwier-dzić, że chitozan mikrokrystaliczny jest polimerem łatwo poddającym się degradacji biologicznej. W badanym zakresie temperatur proces przebiegał najkorzystniej w temperaturze 40°C
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