• Fibers and Polymers
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• v.7 no.3
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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.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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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.

• IE interfaces
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• v.18 no.4
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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.

• Polymer(Korea)
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• v.33 no.4
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• pp.384-388
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• 2009

The rheological properties of poly (acrylonitrile) (PAN) and cellulose acetate (CA) blend solutions in N,N-dimethyl formamide (DMF) were investigated in terms of temperature and blend composition. The solutions exhibited a very characteristic rheological behavior with variation of temperature. 8 wt% solution showed an increase of viscosity and a decrease of loss tangent as temperature was increased over the temperature range of 20 and $60^{\circ}C$. At $20^{\circ}C$ the physical properties of the solutions exhibited dependence on the blend composition. At 40 and $60^{\circ}C$, however, the effects of blend ratio on the physical properties notably diminished. The longer relaxation time at higher temperature indicated that the formation of physical structures resulting from intermolecular interactions was promoted with increasing temperature. The odd rheological responses were further elucidated by measuring of the physical properties of dilute solutions. The intrinsic viscosity of the solutions suggested that the coiled chain dimension was reduced with increasing temperature.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.12 no.2
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• pp.117-123
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• 2006

To mass-product useful biopolymer films, chitosan/gelatin blend films were prepared by solution casting method. Effect of mixing ratio, tensile strength(TS), elongation(${\Delta}E$) at break, total color difference(E), water vapor permeability(WVP) and oxygen permeability(OP) on chitosan/gelatin blend films properties were investigated. TS, ${\Delta}E$, E, WVP and OP values of chitosan/gelatin blend films were 43.43-38.30 MPa, 9.02-15.09%, 1.28-3.81, $0.8420-0.9673ng{\cdot}m/m^2{\cdot}s{\cdot}Pa$ and $1.5472{\times}10^{-7}-1.5424{\times}10^{-7}mL{\cdot}{\mu}m/m^2{\cdot}s{\cdot}Pa$, respectively. TS of the blend films decreased, while E and E of the blend films increased with increasing chitosan content. WVP and OP of the blend films did not show any significant relationship with mixing ratio and thickness of the blend films. OP of the blend films were lower than those of low density polyethylene and oriented polypropylene.

• Journal of Environmental Health Sciences
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• v.24 no.3
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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.

• Journal of the Korean Applied Science and Technology
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• v.17 no.3
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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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• 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.

• Fibers and Polymers
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• v.6 no.2
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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.

• Polymer(Korea)
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• v.36 no.5
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• pp.617-621
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• 2012

PHEAs [${\alpha}$,${\beta}$-poly(2-hydroxyethyl-DL-aspartamides)], a class of poly(amino acid), have been widely studied as biodegradable and biocompatible polymers for potential biomedical and pharmaceutical applications. In this study, we investigated a homogeneous blend of PHEA with poly(N-vinyl pyrrolidone) (PNVP) and its semi-IPN (semi-interpenetrating polymer network) gels. Blend films were prepared by a solution casting method. The resulting blends were totally transparent over the whole composition ranges and the single $T_g$, changing monotonously with composition, was observed by DSC to confirm the miscibility between these two polymers. FTIR was used to discuss the possible hydrogen-bonding interaction between polymers. In addition, semi-IPN type gels were prepared by chemical crosslinking of PHEA/PNVP blend solution using hexamethylene diisocyanate (HMDI) as a crosslinking reagent. The prepared gel was characterized by their swelling property and morphology.