• Fibers and Polymers
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• 제7권3호
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• pp.250-254
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• 2006

Superfine down-powder/viscose blend films were prepared and characterized for their dyeing properties. Down-powder with average size of $2.56{\mu}m$ were suspended in viscose dope and blend films were obtained by solution casting. When the blend films were dyed with acid dye, the dye uptake and K/S values increased with the increase in down-powder content. Amino-acid analyses showed that amino acid component of the down were not affected during the film formation, which confirmed the changes of dye uptake and K/S value.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.983-989
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• 2005

Secondary batteries with high performance are essential in widespread use of modern portable devices such as cellular phones and laptop computers. High energy density, long cycle life, and safety are some of important requirements for secondary battery. To achieve such characteristics, a mixing proportion of electrolyte solution ingredients in the battery should be carefully chosen. In this paper, using statistical design of mixture experiments (DOME), we attempt to find an optimum condition of designing the secondary battery. DOME has a distinct feature in that the experimental region is represented by simplex, rather than hypercube, because the sum of blend proportions should be unity. Several designs based upon this point have been proposed for mixture experiments. Among them, an extreme vertices design is employed in this paper because there are a couple of blend constraints to be considered. In order to investigate how the mixing proportion interacts with other manufacturing factors, a fractional factorial design is also included across the extreme vertices design. As a result, we find that the blend proportion of solution ingredients has a significant effect on battery performances. By simultaneously optimizing two battery capacities, this paper proposes an optimum blend proportion according to process factor settings.

• 산업공학
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• 제18권4호
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• pp.402-411
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• 2005

Secondary batteries with high performance are essential in widespread use of modern portable devices such as cellular phones and laptop computers. High energy density, long cycle life, and safety are some of important requirements for secondary battery. To achieve such characteristics, a mixing proportion of electrolyte solution ingredients in the battery should be carefully chosen. In this paper, using statistical design of mixture experiments (DOME), we attempt to find an optimum condition of designing the secondary battery. DOME has a distinct feature in that the experimental region is represented by simplex, rather than hypercube, because the sum of blend proportions should be unity. Several designs based upon this point have been proposed for mixture experiments. Among them, an extreme vertices design is employed in this paper because there are a couple of blend constraints to be considered. In order to investigate how the mixing proportion interacts with other manufacturing factors, a fractional factorial design is also included across the extreme vertices design. As a result, we find that the blend proportion of solution ingredients has a significant effect on battery performances. By simultaneously optimizing two battery capacities, this paper proposes an optimum blend proportion according to process factor settings.

• 폴리머
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• 제33권4호
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• pp.384-388
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• 2009

폴리아크릴로니트릴(PAN)과 셀룰로오스 아세테이트(CA) 블렌드/디메틸포름아미드(DMF) 용액의 유변학적 특성을 온도와 블렌드 조성비에 대하여 조사하였다. 모든 고분자 용액이 온도 변화에 따라 매우 특징적인 유변학적 거동을 보였다. 8 wt% 용액의 경우 $20{\sim}60^{\circ}C$ 온도범위에서 온도의 증가와 더불어 용액의 점도가 증가하고 손실탄젠트값이 감소하였다. $20^{\circ}C$에서는 용액의 물성이 블렌드의 조성에 영향을 받았으나 40 및 $60^{\circ}C$에서는 조성비가 용액 물성에 미치는 영향이 크게 감소하였다. 더 높은 온도에서의 더 긴 분자 이완시간으로부터 온도가 증가함에 따라 분자간력에 의한 물리적 구조 형성이 촉진된다는 것을 알 수 있었다. 이러한 유변학적 특성에 대한 원인은 묽은 용액의 특성으로부터 유추할 수 있었다. 고분자 용액의 고유점도가 온도가 증가함에 따라 감소하였다.

• 한국포장학회지
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• 제12권2호
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• pp.117-123
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• 2006

유용한 생분해성 필름의 대량생산 시스템에 관한 기초 연구로 키토산과 젤라틴을 이용하여 solution casting 방법으로 비율에 따라 혼합레진을 제조한 후 이를 열 압축기(heat press)로 혼합필름을 제조하였다. 또한, 키토산/젤라틴 혼합필름의 인장강도, 신장률, 색도, 수분 및 산소투과도와 같은 물리적인 특성에 있어 혼합비율이 미치는 효과에 대하여 조사하였다. 혼합비율로 제조된 키토산/젤라틴 혼합필름의 인장강도는 43.43 MPa에서 38.30 MPa로 점차적으로 감소하는 경향을 나타내었고, 신장률은 9.02%에서 15.09%로 인장강도 결과와는 다르게 증가되는 경향을 보였다. 필름의 외관을 결정하는 중요한 특성인 색도측정 결과, L값의 경우 키토산 함량이 증가할수록 혼합필름의 L값은 감소되었고, b값은 L값에 반비례로 증가되었다. 또한, 키토산의 함량이 증가함에 따라 제조된 혼합필름의 ${\Delta}E$ 및 YI 값들은 키토산 함량 15%를 제외하고는 보다 높은 값들로 측정되었다. 수분투과도는 $0.9673mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$에서 $0.8420mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$로 측정되었고, 산소투과도는 혼합비율에 따라 $1.5472{\times}10^{-7}mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$에서 $1.5424{\times}10^{-7}mL{\cdot}mm/m^2{\cdot}s{\cdot}Pa$로 측정되었다. Duncan의 다중비교 분석결과로 키토산의 농도가 증가함에 따라 혼합필름의 수분 및 산소투과도는 유의적인(P < 0.05) 차이를 나타내지 않았다.

• 한국환경보건학회지
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• 제24권3호
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• pp.48-53
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• 1998

Chitin is known as biodegradable natural polymer. But, in spite of various application of chitin from waste marine sources, commercial use of chitin has been limited due to highly resistance to chemicals and the absense of proper solvents. We made various viscosity of chitosan from chitin by change of Mima's method through the deacetylation which is various condition of NaOH concentration, reaction time and temperature. Also, Polyvinyl alcohol/chitosan blend films were prepared by different solution blends containing the ratio of 5, 10, 15 and 20% chitosan and low, medium, high molecular weight of chitosan to find a more useful biodegradable polymer. Thermal and mechanical properties of PVA/chitosan blend films such as DSC, impact strength, tensile strength and morphological changes by SEM were determined. The 10-15% PVA/chitosan(low, medium) blend films were similar to PVA. Also, PVA/chitosan blend films at the laboratory soil test(Pot Test) were completely degraded in month with four kinds of soils by microorganisms.

• 한국응용과학기술학회지
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• 제17권3호
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• pp.198-202
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• 2000

PVA blend films were prepared by solution blending method for the purpose of useful antibiotic polymers. Characteristics properties of blending films such as elongation and tensile strength were determined. Tensile strength and elongation were rapidly reduced as increasing the blending ratio of natural polymer. Blend films were found that phase separation was occured as more than 25wt% increasing the blend ratio of chitosan. Also, The antibiotics of blend films were examined against gram(+) and gram(-) by disk susceptibility test. As a result, kind of blending films to show the highest antibiotics was chitosan 20wt% and the selectivity of mold strain was observed.

• Membrane and Water Treatment
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• 제3권3호
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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.

• Fibers and Polymers
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• 제6권2호
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• pp.121-126
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• 2005

Semicrystalline poly(ethylene terephthalate) (cPET)/amorphous poly(ethylene terephthalate) with isophthalic acid (aPET) blends with 100/0, 75/25, 50/50, 25/75, and 0/100 by weight ratios were dissolved in a mixture of trifluoroacetic acid (TFA)/methylene chloride (MC) (50/50, v/v) and electrospun via the electrospinning technique. Solution properties such as solution viscosity, surface tension and electric conductivity were determined. The solution viscosity slightly decreased as aPET content increased, while there was no difference in surface tension with respect to aPET composition. The characteristics of the electro spun cPET/aPET blend nonwovens were investigated in terms of their morphology, pore size and gas permeability. All these measurements were carried out before and after heat treatment for various blend weight ratios. The average diameter of the fibers decreased with increasing aPET composition due to the decrease in viscosity. Also, the morphology of the electrospun cPET/aPET blend nonwovens was changed by heat treatment. The pore size and pore size distribution varied greatly from a few nanometers to a few microns. The gas permeability after heat treatment was lower than that before heat treatment because of the change of the morphology.

• 폴리머
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• 제36권5호
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• pp.617-621
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• 2012

폴리아스팔트아미드[${\alpha}$,${\beta}$-poly(2-hydroxyethyl-DL-aspartamides), PHEAs]는 폴리아미노산의 일종으로서 잠재적인 의학 및 약학분야에 응용가능한 생분해성 생체적합성 재료로 널리 연구되어 왔다. 본 연구에서는 PHEA와 폴리(비닐 피롤리돈)(PNVP)의 블렌드 및 semi-IPN 젤에 관하여 다루었다. 블렌드 필름은 용액 캐스팅법으로 제조되었다. 제조된 블렌드는 전 조성에서 투명하였으며 DSC를 통해 조성에 따라 단조롭게 변화하는 단일한 유리전이 온도가 관찰됨으로써 두 개 고분자가 서로 상용성이 있음을 확인하였다. 고분자간의 가능한 수소결합 상호작용을 FTIR을 이용하여 설명하였다. 한편, 일정 조성의 PHEA/PNVP 블렌드 용액을 핵사메틸렌디이소시아네이트(HMDI)를 가교제로 사용하여 semi-IPN 타입의 하이브리드 젤을 제조하고, 제조된 젤의 팽윤 물성과 모폴로지를 조사하였다.