• Journal of the Korean Chemical Society
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• v.57 no.4
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• pp.439-446
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• 2013

Chitosan (CS) and hydroxypropylmethyl cellulose (HPMC) blend microspheres were prepared by water-in-oil emulsion technique and were loaded with an anti-cancer drug 5-fluorouracil (5-FU). CS-HPMC microspheres were characterized by Fourier transform infrared spectroscopy to confirm the cross-linking reaction. Scanning electron microscopy (SEM) was also used to assess the surface morphology of particles prepared. The quantity of release of 5-FU from the microspheres have been studied in terms of blend composition and amount of cross-linking agent. Differential scanning calorimetry and X-ray diffraction techniques indicated a uniform distribution of 5-FU particles in microspheres, whereas SEM suggested the spherical structure of the microspheres with slight rough surface. The in vitro drug release indicated that the particle size and release kinetics depend upon blend composition, amount of cross-linking agent used and amount of 5-FU present in the microspheres.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.2
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• pp.347-355
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• 2005

Biodegradability of cotton/polyester blend fabric was investigated employing activated sluge test, soil burial test and enzyme hydrolysis. Surface changes of the degraded sample were observed through a microscopy. Changes in X-ray diffraction patterns and crystallinity were examined using X-ray diffractometer. Experimental results revealed that biodegradability of cotton/polyester blend fabric was proportional to the blending ratio of cotton, not showing any synergy effect. Polyester 100% hardly degraded in this study. Through the comparison of the experimental method it was shown that the biodegradabilities determined from activated sludge test and enzymatic hydrolysis except soil burial test were linearly related to the blending ratio of cotton in the blent fabrics. It is probably because the biodegradability determined from the retention of tensile strength of fabrics buried in soil was affected by the stress distribution of polyesters throughout the fabric. From the microscopic observations it was revealed that fungi were grown on the fabric surface and the colors turned yellow, brown and black. X-ray diffraction patterns showed that the heights of crystalline peak coming from cotton part in blend fabrics decreased whereas those coming from polyester part increased comperatively as time passed by. Crystallinities of cotton 100% fabric increased slightly at the begining and then decreased continuously.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.2
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• pp.213-221
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• 2009

This study provides the optimum papain treatment method and its effect on wool/polyester blend fabrics. The enzymatic treatment condition is optimized depending on its pH level, temperature, concentration of enzyme, treatment time and concentration of activators. The characteristics of samples treated with the papain are measured using weight loss, tensile strength, whiteness, WCA, dyeing property and surface micrographs. The results are described as follows: According to measuring weight loss, tensile strength and whiteness, a pH level of 7.5, $70^{\circ}C$, 10% papain(o.w.f.) and 60minutes of treatment time are optimized for papain treatment. L-cysteine and sodium sulfite are able to activate the papain. The optimum concentrations of them are 10mM and 50mM respectively. The WCA of fabrics is decreased since papain treatment makes wool/polyester blend fabrics more hydrophilic. Scouring with papain treatment improves whiteness and dyeing property of fabrics. The dyeing property of papain-treated fabrics is enhanced simply by a single step dyeing process using a basic dye. The surface of wool treated with papain in the presence of L-cysteine shows to be descaled. The surface of wool fibers in the presence of sodium sulfite, however, shows it is hydrolyzed evenly instead of being descaled. The surface of papain treated polyester fibers shows cracks and voids.

• Polymer(Korea)
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• v.27 no.4
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• pp.307-312
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• 2003

Hollow fiber was prepared from the blend of a high density polyethylene (HDPE)/ultra high molecular weight polyethylene (UHMWPE). The changes in the morphology and mechanical property of the hollow fiber were investigated. The commercial product (Sterapore), having a high water permeability, was analyzed with viscosity measurement and FT-IR. The molecular weight of Sterapore was very high and its surface was coated with a vinyl alcohol/vinyl acetate copolymer. The content of UHMWPE in the HDPE/UHMWPE blend was limited below 10 wt%. In order to improve the dispersion of UHMWPE, a mineral oil should be introduced in the blend. The morphology and mechanical property of the hollow fiber of HDPE/UHMWPE blend were similar to those of the commercial product.

• Macromolecular Research
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• v.14 no.3
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• pp.331-337
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• 2006

In the present study we investigated the relationship between the morphology and mechanical properties of electrospun polysulfone (PSF)/polyurethane (PU) blend nonwovens, by using the electrospinning process to prepare three types of electrospun nonwovens: PSF, PU and PSF/PU blends. The viscosity, conductivity and surface tension of the polymer solutions, were measured by rheometer, electrical conductivity meter and tensiometer, respectively. The electrospun PSF/PU blend nonwovens were characterized by scanning electron microscopy (SEM) and with a universal testing machine. The SEM results revealed that the electrospun PSF nonwoven had a structure consisting of cross-bonding between fibers, whereas the electrospun PU nonwoven showed a typical, point-bonding structure. In the electrospun PSF/PU blend nonwovens, the exact nature of the point-bonding structure depended on the PU contents. The mechanical properties of the electrospun PSF/PU blend nonwoven were affected by the structure or the morphology. With increasing PU content, the mechanical behaviors, such as Young's modulus, yield stress, tensile strength and strain, of the electrospun PSF/PU blend nonwovens were by up to 80%.

• Membrane and Water Treatment
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• v.3 no.3
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• pp.201-209
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• 2012

Membrane separation technologies have some of advantages are considered a better alternative to traditional methods. Research of novel membranes is very vital for covering the higher required of membrane in several purposes like water desalting technology. In this work polyamide-6/cellulose acetate (PA-6/CA) blend membrane was developed according to the wet phase inversion system. The structures of the prepared membranes were examined by scanning electron microscopy (SEM). SEM images showed uniform particles distribution in the prepared membranes. Moreover, SEM images revealed that the membranes have relatively uniform surface (PA-6/CA). PA-6/CA blend membranes systems are evaluated by using synthetic NaCl solution. The separation performance showed that salt rejection increased with increasing of heat treatment of the casted films and it was improved with increasing of operating pressure.

• Journal of the Korean Society for Heat Treatment
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• v.5 no.1
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• pp.23-31
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• 1992

It is investigated that Fe-C-N compound layer, defusion layer, and induction hardened layer produced by nitrocarburizing blend heat treatment in austenitic temperature with high frequency induction heating of mild steel specimen sprayed sursulf salt-bath. As the temperature of blend-heat treatment got increased, the thickness and hardness of compound layer and diffusion layer were increased. Compound layer(max. $35{\mu}m$), diffusion layer (max. 2.5mm) and induction hardened layer were gained in the shortest time 10 sec and in the case of $1000^{\circ}C$ total hardness depth of those was about 3.5mm. When the blend-heat treated specimen was reheated, maximum hardness of compound layer was dropped more than that of the reheated compound layer after sursulf treated, whereas hardness of diffusion layer was increased.

• Polymer(Korea)
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• v.38 no.3
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• pp.265-271
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• 2014

In order to investigate the characteristics of the gradient fluorinated polyacrylate and polyurethane latex blend films, the fluorinated polyacrylate emulsion and the polyurethane emulsion were synthesized, and then the both emulsions were blended at a series of ratios. The effects of content of the fluorinated polyacrylate on the gradient structure and surface property of the blended films were assessed by AFM, XPS, SEM-EDX and surface free energy measurements. It appeared that, while the content of the fluorinated polyacrylate latex was up to 30%, the fluorinated polyacrylate particles were selectively gathered on the film-air (F-A) and film-glass (F-G) interfaces at room temperature. When the content of the fluorinated polyacrylate was under 30%, the gradient structure of fluorinated component was not evident. The further increasing of fluorinated polyacrylate in the mixed system facilitated the formation and enlargement of gradient structure, but the adhesion of film decreased a little.

• Polymer(Korea)
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• v.24 no.2
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• pp.245-251
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• 2000

A blend system prepared from epoxy(EP) and polyurethane (PU) was investigated in terms of the contact angle and mechanical properties. The contents of EP/PU were varied within 100/0~100/60 phr in the presence of 20 phr DDM (4,4'-diamino diphenyl methane) as a curing agent for epoxy resin. Contact angle measurements were performed employing a Rame-Hart contact angle goniometer. Deionized water and diiodomethane were chosen as the testing liquids. In this work, Owens-Wendt and Wu's models using a geometric mean were studied to analyze the surface free energy of blend system. For the mechanical and toughening properties of the casting specimens, the critical stress Intensity factor ($K_{IC}$) and impact test were performed. Especially, the impact test was carried out at room and cryogenic temperatures. As a result, specific or polar component of the surface free energy of the blend system was largely influenced on the addition of the PU resulting in increasing the impact strength for the excellent low- temperature performance.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.9
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• pp.1461-1466
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• 2008

This study provides effects of mixed activators on enzymatic activation and determines optimum mixture ratio for enzymatic treatment. Wool 80% and polyester 20% blend fabric and papain from carica papaya are used in this experiment. L-cysteine and sodium sulfite are used as activators for papain treatment process. The treatment condition is pH 7.5, $70^{\circ}$, papain concentration 10%(o.w.f), 60 minutes. L-cysteine and sodium sulfite are added in enzyme solution with various concentrations($0{\sim}50mM$). The optimum treatment condition is determined by measuring weight loss, tensile strength, whiteness, water contact angle(WCA), dyeability and surface micrographs. The results are as follow; The optimum mixture ratio of activators is L-cysteine 2mM and sodium sulfite 10mM. Mixed activators assists in improving the activation of papain. WCA of papain treated fabrics is decreased since papain treatment with activator mixture makes wool polyester blend fabrics more hydrophilic. Dyeing property of papain-treated fabrics more improves by the treatment with mixed activators than with single activator. It means that this method can save time and lower cost. After papain treatment in the presence of mixed activator, the surface of fabrics is modified. The surface of wool fiber shows to be descaled and hydrolyzed, and that of polyester fiber shows to be cracked.