Chitosan and modified chitosan membranes I. Preparation and characterisation

Blair, H. S.; Guthrie, John D.; Law, Tak-Kau; Turkington, Paul

doi:10.1002/app.1987.070330226

Cited by 166 publications

(78 citation statements)

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“…Thus, it is used in various fields 11 • 12 ranging from a simple flocculant for waste water treatments to medical uses. In particular, interesting observations on the blends of chitosan with some synthetic polymers such as poly(vinyl alcohol), 13 poly-(vinylpyrrolidone), 14 and poly(ethylene oxide) 15 have been reported. Recently, Ratto et al 7 examined the miscibility of chitosan/polyamide blends and reported that the blends are partially miscible.…”

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confidence: 99%

Miscibility of Chitosans/Polyamide 6 Blends

Kim

et al. 1997

Polym J

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ABSTRACT:Chitosans with different degrees of deacetylation were prepared by a chemical method, and miscibility between chitosan and polyamide 6 was examined as a function of the degree of deacetylation in chitosan. From dynamic mechanical analysis and solution viscosity measurement, it may be concluded that there are specific interactions between amorphous regions of both polymers and that the miscibility of the blends becomes better as the degree of deacetylation in chitosan decreases.KEY WORDS Chitosan / Degree of Deacetylation / Polyamide 6 / Blends / Miscibility / Recently, more focus has been concentrated on natural polymers, because natural polymers are inexhaustible resources with biocompatible and biodegradable properties, and they do not cause environmental problems. Therefore, many blending systems containing natural polymers are being studied. 1 -15 Chitosan is an N-deacetylated product of chitin that is the second most abundant polysaccharide in nature. Moreover, it has very useful functional groups such as hydroxyl, amine and acetamide groups, and also shows antimicrobial activity. Thus, it is used in various fields 11 • 12 ranging from a simple flocculant for waste water treatments to medical uses. In particular, interesting observations on the blends of chitosan with some synthetic polymers such as poly(vinyl alcohol), 13 poly-(vinylpyrrolidone), 14 and poly(ethylene oxide) 15 have been reported. Recently, Ratto et al. 7 examined the miscibility of chitosan/polyamide blends and reported that the blends are partially miscible. But, they used solely a chitosan with 80% degree of deacetylation.In this study, we control the degree of deacetylation of chitosan by a chemical method and investigate the miscibility of chitosan/polyamide 6 (PA6) blends as a function of the degree of deacetylation. EXPERIMENT AL MaterialsChitosan was purchased from Sigma Chemical Co., U.S.A. and purified by reprecipitation. 16 Chitosan was dissolved in 5% acetic acid and filtered with stainless steel mesh. The solution was poured into sodium hydroxide solution, and the precipitates were washed and dried in a vacuum at 60°C. The viscosity average molecular weight 1 7 was determined by the Mark-Houwink equation: [17]=KM: where K=l.8x 10-3 cm 3 g-1 in 0.1 M acetic acid/0.2 M NaCl solvent at 25°C and a is 0.93. The viscosity average molecular weight of the raw chitosan was 8.1 x 10 5 g mo1-1 . PA6 was supplied by Hyosung T & C, Korea and used without purification.t To whom correspondence should be addressed.Blending samples were prepared by dissolving chitosan and PA6 in formic acid. The solution was cast on a polystyrene plate and the solvent was evaporated under reduced pressure. Deacetylation and AcetylationTo prepare almost fully deacetylated chitosan, 18 the purified chitosan with 80% deacetylation was deacetylated as following procedure: The chitosan was first treated with 47% sodium hydroxide solution at 110°C for 2 h under nitrogen atmosphere, and the sample was filtered and washed with hot water. This procedure was r...

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Miscibility of Chitosans/Polyamide 6 Blends

Kim

et al. 1997

Polym J

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“…Depending on the requirement, novel properties such as enhanced water solubility, lower critical solution temperature (LCST), improved drugloading capacity, and hemocompatibility can be achieved. Grafting of chitosan with different functionalities may improve the biomedical applications especially in drug delivery [101][102][103][104][105][106]. Some of the grafting techniques for chitosan are discussed in the following subsections.…”

Section: Chitosan-grafted Polymersmentioning

confidence: 99%

Approaches for Functional Modification or Cross‐Linking of Chitosan

Anitha

Rejinold

Bumgardner

et al. 2012

Chitosan‐Based Systems for Biopharmaceuticals

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“…Despite being hygroscopic, chitosan has its water adsorption potentially diminished as its DD increases. This suggests that chitosan samples of higher DD may adsorb less moisture than those of lower DD [74]. Therefore, it is crucial that the polymer must be completely dried prior to the IR test to avoid great discrepancies in the results because even low-moisture content in samples would also contribute to the hydroxyl band that affects the DD values [75].…”

Section: Average Degree Of Deacetylation Of Chitosanmentioning

confidence: 99%