• Macromolecular Research
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• 제12권5호
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• pp.466-473
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• 2004

We have used FT-IR spectra to explain the effects of hydrogen bonding between chitosan and polycaprolactam (PA6). A dynamic mechanical analysis study suggested that the optimum chitosan and PA6 miscibility under the conditions of this experiment were obtained at a blending ratio of 40:60. We studied the thermal degradation of chitosan blended with PA6 (chitosan/PA6) by thermogravimetric analysis and kinetic analysis (by the Ozawa method). Dry chitosan and PA6 exhibited a single stage of thermal degradation and chitosan/PA6 blends having> 20 wt% PA6 exhibited at least two stages of degradation. In chitosan/PA6 blends, chitosan underwent the first stage of thermal degradation; the second stage proceeded at a temperature lower than that of PA6, because the decomposition product of chitosan accelerated the degradation of PA6. The activation energies of the blends were between 130 and 165 kJ/mol, which are also lower than that of PA6.

• 한국가정과학회지
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• 제1권2호
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• pp.119-128
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• 1998

Nonwoven fabrics for diaper coverstock were treated with chitosan solution by pad-dry method. Two chitosans of different molecular weigh(Mw) with similar degree of deacetylation(DDA) were used: Mw 1,800(chitosan oligomer, DDA 84%). Effect of chitosan treatment on the mechanical properties was investigated using KES-FB system. Primary hand values were calculated from mechanical properties using the same equation as the men's suiting equation with minor modification, and total hand values were calculated using new KN-5LNW equation for nonwoven fabrics developed by Kawabata et al. Increase in chitosan treatment concentration increased B, 2HB, WT, LT and RC, and decreased WC continuously. Chitosan treatment affected other mechanical properties regardless of molecular weight. Considering primary hand values obtained from mechanical properties, it was found that chitosan of Mw 180,000 and chitosan oligomer provided softer, smoother, and more bulky at below 0.05% and above 0.5% treatment concentration respectively. Samples treated with 1.0% chitosan oligomer solution, and 0.01％ chitosan solution of Mw 180,000 showed the best total hand values. (Korean J Human Ecology 1(2):119∼128, 1998)

• 대한가정학회지
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• 제43권2호
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• pp.115-126
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• 2005

Environmentally and human compatible chitosan were pretreated on cotton fabrics which were then dyed with 100% persimmon juice. The chitosan concentration was 1% and the chitosan types were high molecular weight chitosan (1980cps), low molecular weight chitosan (18첸), chitosan oligomer and water soluble chitosan. The properties of the fabric surfaces, the dyeabilities, the color fastnesses, the antibacterial activities, the strengths, the elongations and the drape stiffnesses were evaluated. The properties of the chitosanpretreated, persimmon juice-dyed cotton fabrics (CLP) were compared to those of the untreated (CN), chitosan treated (CL) and persimmon juice-dyed fabrics (CP). The results were as follows. The fibers extruded from the surface of CN decreased on CP. The air between the fibers within CN were substituted by chitosan solution or persimmon juiceand decreased within CLP according to SEM observations. The effects of chitosan treatment, the chitosan molecular weights and the degrees of deacetylation of chitosan on the dyeabilities of the persimmon juice-dyed cotton fabric were not distinct. The curing after chitosan padding improved the dyeabilities of CLP compare to noncuring. The strengths of CP decreased and those of CL increased, compared to those of CN. The strengths of CLP were greater than those of CP. The elogations of CP and CL were greater than those of CN. The strengths and elongations of CLP were greater than those of CN. The chitosan treatments improved the strengths but not the elongations. The drape stiffnesses of CL, CP and CLP were greater than those of CN. The antibacterial activites of chitosan pretreated, persimmon juice-dyed cotton fabrics against Staphylococcus aureus were increased by more than 98% by persimmon juice.

• 한국미생물·생명공학회지
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• 제26권4호
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• pp.338-344
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• 1998

게나 새우 등의 갑각류의 껍질에서 주로 얻어지는 생체적합성이 뛰어난 천연고분자인 chitosan에 음이온 수용성의 함인계 단량체인 mono(2-methacryloyl oxyethyl) acid phosphate를 그라프트 중합시켜 새로운 유도체인 chitosan-g-MAP을 합성하였다. 그라프트중합에서 개시제로는 ceric ammonium nitrate을 사용하여 개시제의 농도, 단량체의 농도, 반응온도, 반응시간에 따른 그라프트율, 단량체의 그라프트효율 및 단량체의 총전환율의 변화를 조사하여 최적조건을 규명하였다. 그라프트율은 개시제농도 3.5$\times$$10^{-3}$ M, 단량체농도 0.19 M, 반응온도 4$0^{\circ}C$에서 가장 높은 값을 나타내었고, 반응시간 4시간이 최적조건 이었다. Chitosan의 유리 아민의 함량과 그라프트된 단량체의 종류에 따른 항균성을 Candida albicans, Trichophyton rubrum 및 Trichophyton violaceum에 대하여 조사한 결과, pH 5.75에서 가장 우수한 항균능이 발현되고, 항균제의 농도에 따른 영향에서는 변형chitosan은 C. albicans와 T. violaceum에 대하여 100%의 우수한 항균력을 나타낸 반면, 탈아세틸화도가 다른 DA70과 DA-90인 chitosan은 T. rubrum균에 대해서만 변형 chitosan 보다 우수한 항균성을 나타내었다.

• 대한가정학회지
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• 제42권3호
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• pp.145-158
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• 2004

Experimental conditions for evaluating chitosan antibacterial activities were established. The chitosan antibacterial activities were measured against the Staphylococcus aureus and evaluated for their application to antibacterial textile finishing. The strain of Staphylococcus aureus used in this experiments was KCTC 1916. The chitosan antibacterial activities were estimated from the bacterial densities or ％reduction of bacteria in chitosan solutions and bacterial culture mixtures after incubation under specific conditions. Six parameters as follows were evaluated to optimize the experimental conditions for measuring antibacterial activities. The different combinations of mixtures according to the different ratios of chitosan solutions to the bacterial cultures showed different antibacterial activities. However, the chitosan antibacterial activities could be evaluated by comparing the data obtained from the same combinations of mixtures. The solvent influence on the chitosan solution antibacterial activities could be eliminated using control solution containing the same concentration of acetic acid. The initial pH of the chitosan -bacterial mixtures also affected the chitosan antibacterial activity; at a higher pH, higher activity in terms of ％reduction of bacteria was observed. In case of the bacterial solution without either the acetic acid or chitosan, the initial pH of the solution did not significantly affect bacterial growth. The ％ reduction of bacteria increased when contact times of bacteria with chitosan in the chitosan -bacterial mixture were expended upto 24 hours. However, the chitosan antibacterial activities could be successfully evaluated at contact time 0 where the chitosan-bacterial mixture was plated immediately after mixing and incubated to measure the bacterial number to 24 hours. Evaluating ％reduction of bacteria in the test mixtures after incubation were not changed when the inoculated bacterial concentrations were 2.3${\times}$10$\^$0/ml to 2.3${\times}$10$\^$6/ml. The optimal range of incubation time of the petri-Dish after plating the chitosan-bacterial mixture was 24 to 72 hours depending on the antibacterial activities of the test solutions.

• 한국축산식품학회지
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• 제24권1호
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• pp.1-7
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• 2004

분자량을 달리한 chitosan 침지처리가 한우육의 저온저장 중 품질특성에 미치는 영향을 조사하였다. 150 kDa과 600kDa의 분자량을 갖는 chitosan을 1% acetic acid에 0.5%씩을 용해하고 pH를 5.5로 조정한 후 한우육의 우둔부위를 5분간 침지시킨 후 $1^{\circ}C$에서 저장하면서 실험하였다. 실험결과, pH는 chitosan(600 kDa) 처리구가 다른 처리구들에 비해 유의적으로 높은 값을 나타내었다(p＜0.05). 명도(L＊)는 저장 3일까지는 chitosan(600 kDa) 처리구가 유의적으로 높은 값을 보였으나, 6일 이후부터는 처리구간에 유의적인 차이를 보이지 않았다(p>0.05). 적색도의 경우는 저장 전에는 처리구간에 유의적인 차이를 보이지 않았으나 12일 저장시에는 chitosan(150 kDa) 처리구에서 유의적으로 높은 적색도를 보이는 것으로 나타났다. 또한 chitosan(600 kDa)처리구에서 저장 시 표면에 생성되는 metmyoglobin(%)의 함량은 유의적으로 낮은 함량을 나타내었다(p＜0.05). 또한 저장기간을 결정할 수 있는 육표면에서의 총균수 실험결과는 저장 전에는 chitosan(600 kDa)처리구가 가장 낮은 총균수를 보였으나 저장기간이 증가함에 따라 chitosan(150 kDa)처리구가 chitosan (600 kDa)처리구보다 항균효과가 더 높게 나타나는 경향을 보여 저장 안정성이 높음을 알 수 있었다. 전단력은 전체적으로 다른 처리구에 비해 chitosan(150 kDa)처리구가 유의적으로(p<0.05) 낮은 값을 보여 연도가 향상되었음을 알 수 있었다. 따라서 침지처리시 chitosan의 분자량이 한우육의 품질을 결정하는 중요한 요인으로 사료된다.

• 패션비즈니스
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• 제11권5호
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• pp.51-63
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• 2007

Chitosan, a natural cationic macromolecular material, has been known for its moisturizing and healing effect due to the coating action based on strong ionic bonding when the chitosan is treated on hair strands. In this study, the acidic aqueous chitosan solution was prepared to treat healthy hair, and damaged hair due to bleaching, relatively thin hair and thick hair specimens. The chitosan treatment effect was reviewed by comparing spectrophotometric and mechanical characteristics of the chitosan treated and untreated specimens. Electrostatic voltage was somewhat reduced after the chitosan treatment. Smoothly coated surface was observed, in the SEM images, especially for damaged hair specimens. The values of breaking strength, which is one of the indicators of the internal characteristics of hair, was high in the case of chitosan treated samples. The values of elongation was also high in the case of chitosan treated samples, which proves the chitosan treatment effect. The friction force, one of the indicators of surface characteristics, was reduced for the case of chitosan treated samples.

• Journal of Nutrition and Health
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• 제30권7호
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• pp.770-780
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• 1997

This study was performed to investigate the effect of chitosan and NOCC from different sources and of different molecular weights on lipid metabolism. Sprague-Dawley rats were blocked into 26 groups according to body weight, and were raised for 4 weeks. Cadmium chloride was given at the level of 0 or 400 ppm in diet. Various chitosan and NOCC sources were given at the level of 0%(w/w) of diet. Total serum cholesterol and serum triglyceride concentrations were little affected by chitosan and NOCC supplements. However, HDL-cholesterol concentration and HDL : total cholesterol ratio were increased , and liver lipid, cholesterol , and triglyceride concentration were decreased by chitosan and NOCC supplements. The cholesterol and lipid lowering activity depends on fiber sources(crab and shrimp); type (chitosan and NOCC); and molecular weight(low , medium , and high). Among cadmium-free groups, chitosan-fed groups showed greater activity than NOCC -fed groups in lowering cholesterol and lipid levels, and greater fecal excretion of lipids and bile acids. Crab chitosans were more effective in cholesterol and lipid lowering activity than shrimp chitosans. The group fed high molecular weight crab chitosan showed the highest fecal excretion of lipids and bile acids. This indicated that high molecular weight crab chitosan was most effective in interfering with cholesterol and lipid absorption.

• 복식문화연구
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• 제12권6호
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• pp.999-1009
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• 2004

Chitin is a derived product from the shell of shrimp or crab. Chitosan, a deacetylated product of chitin, has widely been used in the biomedical sector, food industry, and textile industry. Chitosan exhibits fiber-forming property under certain conditions. Nonwoven fabrics made of chitosan fibers may have diverse applications in the industry. Previous studies have revealed that the dye uptake properties of natural dyestuffs improved by the chitosan pretreatment on the fabric specimens. In this case, fabric specimen is coated with acidic salt form of chitosan, which is different from the pure chitosan, since the coating process employes coating with the acidic solution of the chitosan and subesquent drying. In this study, chitosan nonwoven fabric samples were prepared from chitosan sample having deacetylation degree of $100\%$ and molecular weight of 650,000. Chitosan nonwoven fabrics maintain the form of $-NH_2$ end-group. These in turn exhibit higher dye uptake ability than the fabrics coated with chitosan acidic solutions do.

• 한국의류산업학회지
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• 제5권5호
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• pp.529-538
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• 2003

Chitosan should be satisfied a certain Mw range for the final application, Low molecular weight chitosan(LMWC) can be acquired by depolymerizing high molecular weight starting chitosan. Using $H_2O_2$ in depolymerizing chitosan is very effective and reproducible in controlling Mw of resulting LMWC. However, $H_2O_2$ can break glycoside linkage of chitosan and oxidize some $-NH_2$ groups in chitosan. It has been reported that decrease in DA(degree of deacetylation) of LMWC prepared by $H_2O_2$. However, any quantitative data of decrease in DA has not been reported yet. In this study, DA of initial chitosan and DA of $H_2O_2$ treated chitosan were measured and the change in DA of chitosan upon $H_2O_2$ treatment were investigated. Change in DA was very different upon $H_2O_2$ treatment condition. LMWC also showed DA change upon time passage. Pre-swelling treatment of initial chitosan and low ratio of $H_2O_2$/chitosan prevented a decrease in DA significantly. Yellowing of LMWC was detected upon time passage, however, decrease in DA was minimal (around 1%).