• Title/Summary/Keyword: Crosslinked

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Crosslinking of $\beta$-Cyclodextrin on Cholesterol Removal from Milk

  • Kim, S.H.;Ahn, J.;Kwak, H.S.
    • Archives of Pharmacal Research
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    • v.27 no.11
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    • pp.1183-1187
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    • 2004
  • This study was designed to develop crosslinking of $\beta$-cyclodextrin ($\beta$-CD), and determine the optimum conditions of different factors (mixing time, mixing temperature, and mixing speed) on cholesterol reduction from milk. Crosslinked $\beta$-CD was prepared with epichlorohydrin. When milk was treated with different conditions, the cholesterol removal rate was in the range of 79.4 to 83.3% with 1 % crosslinked $\beta$-CD addition, which were not significantly different among treatments. After cholesterol removal from milk, the used crosslinked $\beta$-CD was washed for cholesterol dissociation and reused. For recycling study, the cholesterol removal rate in first trial was 81.8%, which was mostly same as that using new crosslinked $\beta$-CD. With five trials repeatedly using the same sample, the mean cholesterol removal rate was 81.2%. The present study indicated that the optimum conditions on cholesterol removal using crosslinked $\beta$-CD were 10 min mixing with 400 rpm speed at $5^{\circ}C$ with about 80% cholesterol removal. In addition, crosslinked $\beta$-CD resulted in the effective recycling efficiency almost 100%.

Natural Dyeing of Chitosan Crossinked Cotton Fabrics(IV) - Cochineal - (키토산 가교 처리된 면직물의 천연염색에 관한 연구(IV) - 코치닐을 중심으로 -)

  • Kwak, Mi-Jung;Lee, Shin-Hee
    • Fashion & Textile Research Journal
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    • v.12 no.3
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    • pp.381-388
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    • 2010
  • The purpose of this study was investigate the dyeing property on chitosan crosslinked cotton fabric with cochineal at variable conditions. Chitosan crosslinked cotton fabrics were manufactured by crosslinking agent epichlorohydrin in the presence of chitosan. Chitosan crosslinked cotton fabrics dyed using cochineal were post-mordanted using Al, Fe and Cu. The dyeability(K/S) of chitosan crosslinked cotton fabrics were measured by computer color matching. Additionally the fastness to washing and light were also investigated. The dye-uptake of chitosan crosslinked cotton fabrics increased with the dyeing time. The saturated dyeing time was about 20minutes at $60^{\circ}C$. The dyeability(K/S) was remarkably increased with increasing content of crosslinked chitosan because of having a amine group of chitosan. Chitosan crosslinked cotton fabrics were dyed yellowish red by non and Fe mordanting, blueish red by Al and Cu mordanting, respectively. The washing and light fastness were increased by mordanting, especially Cu and Fe mordanting.

Mechanical Properties and Degradability of Degradable Polyethylene Films Containing Crosslinked Potato Starch (가교결합 감자 전분을 함유한 분해성 polyethylene 필름의 기계적 성질 및 분해 특성)

  • Kim, Mee-Ra;Lee, Sun-Ja
    • Korean Journal of Food Science and Technology
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    • v.32 no.6
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    • pp.1298-1305
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    • 2000
  • Potato starches were crosslinked with 0.1, 0.5, 1.0, and 2.0% epichlorohydrin. Starch/polyethylene(PE) cast films were prepared to contain 5% of the crosslinked potato starch. Mechanical properties and degradability of these films were measured and compared to those of the films containing native potato starch. Mechanical strength of the films containing crosslinked potato starch was higher than that of the film containing native starch. Thermal degradability measured by a FT-IR and an Instron showed that crosslinked starch/PE films degraded faster than native starch/PE films. Biodegradability of the starch/PE films was accelerated by the addition of crosslinked starch to the PE films.

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Entrapment of Milk Nutrients during Cholesterol Removal from Milk by Crosslinked β-Cyclodextrin

  • Ha, H.J.;Jeon, S.S.;Chang, Y.H.;Kwak, H.S.
    • Food Science of Animal Resources
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    • v.29 no.5
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    • pp.566-572
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    • 2009
  • This study was designed to elucidate the quantities of milk nutrients entrapped during cholesterol removal from milk by crosslinked $\beta$-cyclodextrin ($\beta$-CD, 0.4~1.2%, w/v) and to evaluate the amounts of the residual $\beta$-CD in cholesterol-reduced milk treated by crosslinked $\beta$-CD. The content of lactose in the control milk (without treatment by crosslinked $\beta$-CD) was 4.86%, and the amounts of lactose entrapped by crosslinked $\beta$-CD ranged from 0.00 to 0.03%. The total amounts of the entrapped short-chain free fatty acid (FFA) and free amino acid (FAA) ranged from 0.03 to 0.09 ppm and from 0.28 to $0.71{\mu}mol/mL$, respectively. The amounts of the entrapped water-soluble vitamins (L-ascorbic acid, niacin, thiamine and riboflavin) ranged from 0.02 to 0.05 ppm, 0.01 to 0.06 ppm, 0.00 to 0.06 ppm and 0.01 to 0.06 ppm, respectively. The entrapped amounts of lactose, short-chain FFAs, FAAs and water-soluble vitamins were not remarkably affected by the concentrations of crosslinked $\beta$-CD (0.4~1.2%, w/v). Only very small amounts of residual $\beta$-CD in the cholesterol-removed milk were measured (1.22~3.00 ppm). Based on the data obtained from the present study, it was concluded that the amounts of entrapped nutrients were negligible during cholesterol removal from milk by crosslinked $\beta$-CD, and only trace amounts of residual $\beta$-CD were present in cholesterol-removed milk.

Synthesis of Chelating Adsorbent (2,2'-Iminodibenzoic Acid-crosslinked Chitosan) and Adsorptivity of Pb(II), Cu(II), Cd(II) (킬레이트 흡착제(2,2'-Iminodibenzoic acid-가교 chitosan)의 합성과 Pb(II), Cu(II), Cd(II)의 흡착력에 관한 연구)

  • Shim, Sang-Kyun;Ryu, Jae-Jun
    • Analytical Science and Technology
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    • v.11 no.6
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    • pp.452-459
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    • 1998
  • Crosslinked chitin was prepared from epichlorohydrin and chitin which was isolated from waste marin source. The crosslinked chitosan were prepared by the deacetylation of the crosslinked chitin with a strong base. 2,2'-Iminodibenzoic acid-crosslinked chitosan was prepared by reacting 2,2'-Iminodibenzoic acid salt with crosslinked chitosan-Cl which was obtained by chlorination of crosslinked chitosan. The adsorptivity of Pb(II), Cu(II), Cd(II) was studied as a synthetic adsorbent. Experimental results for the adsorption and the recovery characteristics showed that the more pH increase, the more amount of adsorbed metal ion increase. Optimum adsorption time was 1 hr, and adsorption capacity was increased in order of $Cu^{2+}$<$Cd^{2+}$<$Pb^{2+}$, and recovery capacity was increased in order of $Cd^{2+}$<$Cu^{2+}$<$Pb^{2+}$.

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Tissue integration patterns of non-crosslinked and crosslinked collagen membranes: an experimental in vivo study

  • Xiang Jin;Jin-Young Park;Jung-Seok Lee;Ui-Won Jung;Seong-Ho Choi;Jae-Kook Cha
    • Journal of Periodontal and Implant Science
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    • v.53 no.3
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    • pp.207-217
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    • 2023
  • Purpose: Non-crosslinked and crosslinked collagen membranes are known to exhibit distinct degradation characteristics, resulting in contrasting orientations of the adjacent tissues and different biological processes. The aim of this study was to conduct a histomorphometric assessment of non-crosslinked and crosslinked collagen membranes regarding neovascularization, tissue integration, tissue encapsulation, and biodegradation. Methods: Guided bone regeneration was performed using either a non-crosslinked (BG) or a crosslinked collagen membrane (CM) in 15 beagle dogs, which were euthanized at 4, 8, and 16 weeks (n=5 each) for histomorphometric analysis. The samples were assessed regarding neovascularization, tissue integration, encapsulation, the remaining membrane area, and pseudoperiosteum formation. The BG and CM groups were compared at different time periods using nonparametric statistical methods. Results: The remaining membrane area of CM was significantly greater than that of BG at 16 weeks; however, there were no significant differences at 4 and 8 weeks. Conversely, the neovascularization score for CM was significantly less than that for BG at 16 weeks. BG exhibited significantly greater tissue integration and encapsulation scores than CM at all time periods, apart from encapsulation at 16 weeks. Pseudoperiosteum formation was observed in the BG group at 16 weeks. Conclusions: Although BG membranes were more rapidly biodegraded than CM membranes, they were gradually replaced by connective tissue with complete integration and maturation of the surrounding tissues to form dense periosteum-like connective tissue. Further studies need to be performed to validate the barrier effect of the pseudoperiosteum.

Mechanical Properties of Crosslinked Starch-Filled Waterborne Acrylate Film and Biodegradation by α-Amylase (가교 전분을 충전한 수성 아크릴레이트 필름의 기계적 특성과 α-Amylase에 의한 생분해)

  • Kim Jung-Du;Kam Sang-Kyu;Lee Min-Gyu
    • Journal of Environmental Science International
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    • v.14 no.3
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    • pp.359-366
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    • 2005
  • Starch was crosslinked with epichlorohydrin. Crosslinked starch-filled waterborne acrylate (CSWAC) films were prepared by blending this crosslinked starch with waterborne acrylate. The thermal and mechanical properties of these films were investigated by thermogravimetric analysis (TGA), tensile strength and elongation test. The biodegradability was also studied by determination of reduced sugar products after enzymatic hydrolysis and the surface morphology was investigated by scanning electron microscopy (SEM). The CSW AC film showed significantly higher tensile strength and elongation than those of starch-filled waterbonre acrylate (SWAC). The biodegradability of this film was higher than that of native starch-filled acrylate film, and was increased by the addition of crosslinked starch to the acrylate film.

Properties of Blood Compatible Crosslinked Blends of $Pellethene^{(R)}$/Multiblock Polyurethanes Containing Phospholipid Moiety/C-18 Alkyl Chain

  • Yoo, Hye-Jin;Kim, Han-Do
    • Macromolecular Research
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    • v.16 no.7
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    • pp.596-603
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    • 2008
  • To improve the mechanical properties, dimensional stability and blood compatibility, the biomedical material $Pellethene^{(R)}$ was blended with multiblock polyurethane (MPU) containing phospopholipid/long alkyl chain (C-18) at the various MPU contents and crosslinked using dicumyl peroxide as a crosslinking agent. The maximum MPU content for stable $Pellethene^{(R)}$/MPU blended films was approximately 30 wt%. The optimum crosslinking agent content and crosslinking time with respect to the mechanical properties were 4 wt% and 3 h, respectively. The mechanical properties (tensile strength and elongation at break) and water absorption of the crosslinked blend film increased with increasing MPU content. The test of platelet adhesion on the surfaces of the crosslinked blend film showed a decrease in the level of platelet adhesion from 70% to 6% with increasing MPU content from 0 to 30 wt%. These results suggest that the crosslinked $Pellethene^{(R)}$/MPU-30 (MPU content: 30 wt%) sample has strong potential as a novel material for blood compatible material applications.

Physicochemical Properites of Potato Starches Crosslinked with Epichlorohydrin (Epichlorohydin으로 가교결합시킨 감자 전분의 이화학적 특성)

  • 김미라;이선자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.1
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    • pp.132-139
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    • 1999
  • Physicochemical properties of the crosslinked potato starches of MDC(Molar Degree of Crosslinking) 0.137~3.333 treated with epichlorohydrin were examined. MDC increased proportionally as epichlorohydrin concentration increased. Water binding capacity increased but blue value decreased with increasing MDC. Gelatinization trends obtained from DSC thermograms and transmittance showed that the gelatinization temperature of the crosslinked potato starch was higher than that of native potato starch, but there was no significant difference among the crosslinked potato starches. Solubility and swelling power decreased with increasing MDC. X ray diffraction patterns and scanning electron micrographs showed that the crosslinking of starch did not affect the crystallinity and the granule shape of starch.

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A Study on the Aging Characteristics and Life Diagnosis of Insulating Materials for Power Cable (전력케이블용 절연재료의 열화특성 및 수명진단에 관한 연구)

  • 박홍태;김경석;남창우;이규철
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.11-17
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    • 1999
  • Aging characteristics of the crosslinked polyethylene have been measured after applying electrical, thermal and combined stresses. ICP and FT-IR measurements confirmed diffusion of low molecular weight components such as antioxidant and presence of carbonyl group. Carbonyl group of aged crosslinked polyethylene under combined stress was detected by FT-IR. As deterioration of the crosslinked polyethylene progresses, crystallinity degree and density decrease. Also, dielectric properties have been measured by tan $\delta$ and $\varepsilon$$_{r}$ measurements. The three-parameter Weibull distribution was found to be the best suited among other probabilistic distribution representing the dielectric breakdown strength of aged crosslinked polyethylene. The scale parameter and location parameter decreases as the applied stress increases. The shape parameter increases as the stress increases.s.

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