Characterization of chitosan by pyrolysis-mass spectrometry, thermal analysis and differential scanning calorimetry

Nieto, José Miguel; Covas, Carlos Peniche; ́n, G. Padro

doi:10.1016/0040-6031(91)80260-p

Cited by 103 publications

(68 citation statements)

References 4 publications

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“…The non-cross-linked chitosan and GA-cross-linked chitosan membranes show a two-stage decomposition process, but the doubly cross-linked chitosan membrane shows a three-stage thermal degradation. Similar results were obtained earlier for chitosan and cross-linked chitosan [11][12][13]. For all polymer membranes the first stage starts at about 50°C and continues up to 180°C and is accompanied by a weight loss ranging from 1 to 4 %.…”

Section: Resultssupporting

confidence: 75%

“…For all polymer membranes the first stage starts at about 50°C and continues up to 180°C and is accompanied by a weight loss ranging from 1 to 4 %. This stage can be assigned to the evaporation of the residual, physically adsorbed water present in the polymer samples, which could not be removed completely by drying [11,12], The content of this water is a function of the morphology, crystallinity and hydrophilicity of the polymers.…”

Section: Resultsmentioning

confidence: 99%

“…Different decomposition products were observed by TGA coupled with FTIR spectroscopy, mass spectrometry and chromatography [12,14]. According to literature data pyrolysis of chitosan starts by a random splitting of the glycosidic bonds, followed by a further decomposition to acetic, butyric and lower fatty acids [11,12].…”

Section: Thermal Properties Of Hydrogel Membranesmentioning

confidence: 99%

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pH-responsive hydrogel membranes based on modified chitosan: water transport and kinetics of swelling

2015

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pH-responsive membranes prepared by treating chitosan (Ch) with glutaraldehyde (GA) or with GA and sulfuric acid (SA) were studied. The structure and properties of the membranes were characterized by Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis. The effect of the cross-linking process both on the dynamic swelling behaviour of the hydrogel membranes and on the mechanism of water transport through those membranes was investigated in buffer solutions of different pH (1.2-9.5). The mechanism of water transport through the hydrogel chitosan membranes was affected by membrane composition and pH of the swelling medium. Non-cross-linked Ch membrane showed a non-Fickian swelling behaviour in the pH range 6.5-9.5. Chitosan membrane cross-linked with GA (Ch/GA) showed less-Fickian or Fickian swelling behaviour in all buffer solutions. In the case of chitosan membrane cross-linked with GA and SA (Ch/GA/SA), at low pH (lower than the pK a of the hydrogel) the water transport was controlled more by polymer relaxation than by penetrant diffusion. The experimental data clearly suggested that the swelling process in all buffer solutions obeyed second-order kinetics. Values of an apparent swelling rate constant for Ch/ GA and Ch/GA/SA membranes were of the same order of magnitude for acidic and neutral swelling media but they increased for alkaline solutions.

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Section: Resultssupporting

confidence: 75%

Section: Resultsmentioning

confidence: 99%

Section: Thermal Properties Of Hydrogel Membranesmentioning

confidence: 99%

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pH-responsive hydrogel membranes based on modified chitosan: water transport and kinetics of swelling

2015

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“…Elas mostram uma perda de massa em dois estágios. O primeiro estágio (da temperatura ambiente até cerca de 200 o C) é atribuído à perda de água adsorvida e estrutural contida nos materiais, e o segundo estágio, iniciando-se próxi-mo de 200 o C e indo até 500 o C, é atribuído à degradação dos polímeros [23][24][25] . A Tabela 2 mostra a porcentagem de perda de massa dos materiais nos dois estágios e a quantidade de resíduo restante à 600 o C. De acordo com a perda de massa do primeiro estágio, verifica-se que, aumentando a quantidade de quitosana nas blendas, maior é a quantidade de água perdida.…”

Section: Termogravimetriaunclassified

Obtenção e caracterização de blendas colágeno-quitosana

Tonhi¹,

Plepis²

2002

Quím. Nova

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Recebido em 15/8/01; aceito em 19/2/02 PREPARATION AND CHARACTERIZATION OF COLLAGEN-CHITOSAN BLENDS. Biodegradable polymer blends were obtained using collagen and chitosan. Membranes of collagen and chitosan in different proportions (3:1, 1:1 and 1:3) were prepared by mixing their acetate solutions (pH 3.5) at room temperature. The blends were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Fourier Transform infrared (FTIR) spectroscopy, specific viscosity, water absorption and stress-strain assays. The results showed that chitosan did not interfere in the structural arrangement of the collagen triple helix and the properties of the blends can be controlled by varing the proportion of the collagen and the chitosan.Keywords: blends; collagen; chitosan. INTRODUÇÃOO colágeno é uma proteína fibrosa presente na pele, tendões, ossos, dentes, vasos sangüíneos, intestinos e cartilagens, correspondendo a 30% da proteína total e a 6% em peso do corpo humano.A quitosana é um copolímero constituído de b-(1-4)-2-amino-2-deoxi-D-glicopiranose e b-(1-4)-2-acetamida-2-deoxi-D-glicopiranose, proveniente da reação de desacetilação da quitina, o segundo polissacarídeo mais abundante na natureza.O colágeno e a quitosana têm sido bastante utilizados na medicina, odontologia e farmacologia como biomateriais, pois são polímeros biocompatíveis, atóxicos e biodegradáveis, além de possuírem inú-meras propriedades biológicas [1][2][3][4][5][6] . As blendas poliméricas constituem-se na mistura de pelo menos dois polímeros ou copolímeros sem que haja qualquer reação quími-ca entre eles 7 . O interesse nesta área deve-se às crescentes aplicações práticas destes novos materiais e os principais estudos são voltados para a melhoria de suas propriedades físicas, físico-químicas e de processamento destes materiais, comparadas às propriedades dos polímeros puros 8 . Muitas blendas formadas pela combinação de biopolímeros, têm grande importância na área de biomateriais, sendo que é possível juntar as propriedades individuais de cada material em um só, além da possibilidade de melhorar ou controlar as suas propriedades mecânicas e biológicas através da interação entre as suas estruturas quí-micas diferentes. Recentemente, membranas e hidrogéis provenientes da mistura de colágeno e quitosana foram investigados pelas suas aplicações potenciais no campo dos biomateriais 9,10 . Já foi demostrado que as interações entre o colágeno e a quitosana dependem da organização estrutural do colágeno e da quantidade e distribuição de cargas ao longo das cadeias dos dois polímeros 11 . Estas propriedades estão diretamente relacionadas com o pH do meio, que é uma propriedade de fundamental importância para o estudo da interação entre eles em solução.Este trabalho teve por objetivos obter blendas colágeno-quitosana em diferentes proporções (3:1, 1:1 e 1:3) em pH 3,5, estudar a interação entre estes dois biopolímeros tanto na forma de membranas como em solução e avaliar suas propriedades físico-químicas. PARTE EXPERIMENTAL C...

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“…22 SCs are thermally unstable. This change might render the material more hydrophilic following sulfonation and destroy the crystalline structure.…”

Section: 폴리머 제38권 제1호 2014년mentioning

confidence: 99%

Preparation of Sulfobetaine Chitosan, Silk Blended Films, and Their Properties

Koo¹,

Cha²,

Oh³

et al. 2014

Polymer Korea

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Water-soluble sulfobetaine chitosan (SCs) was prepared for a blending film with Bombyx mori silk fibroin (SF) by reacting chitosan with 1,3-propanesultone. A series of SF/SCs blended films were successfully prepared by mixing aqueous solutions of B. mori SF and SCs. The SF/SCs blended films were examined through spectroscopic and thermal analysis to determine the morphological changes of SF in the SCs. The effects of the SF/SCs blend ratios on physical and mechanical properties were investigated to discover the feasibility of using these films as biomedical materials such as artificial skin and wound dressing. X-ray analysis showed good compatibility between the two biopolymers. The in vitro degradation behavior of the SF/SCs blended films was systematically investigated for up to 8 weeks in phosphate buffered saline solution at 37 o C and showed a mass loss of 46.4% after 8 weeks. All films showed no cytotoxicity by MC3T3-E1 assay. After 3 days of culture, the relative cell number on all the SF/SCs films was slightly lower than that of an optimized tissue culture plastic.

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Characterization of chitosan by pyrolysis-mass spectrometry, thermal analysis and differential scanning calorimetry

Cited by 103 publications

References 4 publications

pH-responsive hydrogel membranes based on modified chitosan: water transport and kinetics of swelling

pH-responsive hydrogel membranes based on modified chitosan: water transport and kinetics of swelling

Obtenção e caracterização de blendas colágeno-quitosana

Preparation of Sulfobetaine Chitosan, Silk Blended Films, and Their Properties

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