• Polymer(Korea)
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• v.34 no.3
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• pp.269-273
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• 2010

The primary objective of this work is to find the optimal condition for the granule tablet formulation of alfuzosin-HCl that aims to achieve a sustained drug release. (Hydroxypropyl)methyl cellulose (HPMC) is one of the most widely used polymer as a drug formulation and therefore has been utilized in this study as an excipient. Alfuzosin-HCl granule tablet was developed using the various viscosities of HPMC and the effects of viscosity on drug release was investigated. Fourier transform-infrared (FTIR) and X-ray diffraction (XRD) were employed to investigate the chemical structure and crystallization of alfuzosin-HCl in the formulation. We prepared the granule tablet by a direct compression method and studied the release profile in the stimulated intestinal fluid (pH 6.8). As the viscosity of HPMC increased the release of alfuzosin-HCl decreased, demonstrating that controlled release of alfuzosin-HCl can be achieved by varying the viscosity of HPMC.

• Textile Coloration and Finishing
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• v.29 no.3
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• pp.122-130
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• 2017

In the direct digital textile printing process, the pre-treatment process is an essential condition for products by forming a clear pattern by sticking and penetration of DTP dye without spreading on the fabric. Recently, pre-treatment agent is changing from high viscosity to low viscosity in order to reduce defects of fabric during pre-treatment process. In this study, pre-treatment agent of acrylic polymer with low viscosity(less than 50cps) was prepared according to the solid content of the polymer, pre-treated on the cotton fabric, and direct DTP printing was performed to compare the color and sharpness. As a result, it showed high color at a viscosity of 50cps or less. When the solid content of the polyacrylic acid having a high molecular weight(A1) was 2.5wt%, when the solid content of the polyacrylic acid having a low molecular weight(A2) was 1 - 1.5wt%, the color was the best. And when the solid content of A1 and A2 was 1.5wt%, the degree of spreading was small and A1 was superior to A2 at the sharpness.

• Tribology and Lubricants
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• v.26 no.2
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• pp.97-104
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• 2010

A new magnetoelastic technique of oil viscosity measurement, where the oil viscosity is estimated by frequency shift of natural oscillations of magnetoelastic ribbon, is implemented in this study. Laboratory tests of the detector prototype are performed for measurement of viscosity of base synthetic and mineral oils. It was found that measurement accuracy was better when damping factor was estimated in comparison with accuracy of frequency of damped oscillations. Thus the oil viscosity was calibrated as a function of number of pulses of the damped oscillations of magnetoelastic ribbon. Result generally showed that developed detector is promising for in line oil viscosity measurement in wide viscosity range from 10 cSt up to 600 cSt, while the viscosity measurement was relatively instable when the viscosity of test oil was over 400 cSt.

• Korea-Australia Rheology Journal
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• v.11 no.4
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• pp.269-273
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• 1999

Immiscible polymer blends containing a liquid crystalline polymer dispersed phase can be described by existing blend theories when the dispersed-phase droplets are large relative to the orientation correlation length ("domain size") of the LCP. There does not appear to be an interfacial contribution to the linear viscoelastic properties of the blend from droplets smaller than the correlation length. Polyester blends, where interfacial interactions occur between the LCP and the matrix, exhibit a reduction in viscosity to below the viscosity of either component at low shear rates, where the droplet morphology is spherical. These anomalies cannot be explained in the context of existing theory.ng theory.

• Journal of Pharmaceutical Investigation
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• v.25 no.4
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• pp.339-345
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• 1995

For the effective treatment of aphthous stomatitis, the matrix type mucoadhesive patches containing triamcinolone acetonide have been formulated. The drug layer was obtained by drying the polymer gel which was prepared with carbomer 934P, ammoniomethacrylate copolymer, titanium dioxide and polyethylene glycol 400. The effects of the content of additives on physical characteristics of the polymer gel and the drug layer were evaluated. The addition of carbomer increased the yield point and the zero-shear viscosity of polymer gel as well as the thickness, the water absorption ratio, the adhesive time and $T_{50%}$ of drug layer. The adhesive time and the water absorption ratio of drug layer were also improved by the addition of ammoniomethacrylate copolymer, but the addition of titanium dioxide had decreased the zero-shear viscosity of polymer gel and the adhesive time of drug layer.

• Macromolecular Research
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• v.8 no.5
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• pp.243-245
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• 2000

can be determined from the number and weight average molecular weight. When the value of the exponent, a, appearing in the relation between the intrinsic viscosity and the viscosity average molecular weight, is in the range from 0.6 to 0.8, as is the case for the most polymers, the viscosity average molecular weight is much more close to the weight average molecular weight than to the number average molecular weight.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.667-671
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• 1995

The viscometric technique is used to study the effects of microstructure on the viscosity (viscosity vs. concentration or shear rate) of magnetic particle suspensions. In this characterization, measurement of suspension viscosity is used to obtain the dependence of viscous energy dissipation on microstructural state of dispersions. Microstructural shape effects which are related to particle orientation are then indirectly obtained. Empirical formulas from mean field theory and the Mooney equation, which are applicable at high concentration of magnetic particles, are used to relate viscosity to particle concentration. The validity and physical meaning of these equations are discussed.

• The Korean Journal of Rheology
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• v.1 no.1
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• pp.12-19
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• 1989

Polymer fluid flow and polymerization reaction occur simultaneously during the reactive polymer processing. The viscosity and physical properties change as thereaction proceeds and the crystallization and vitrifica-tion occur as the T,,,and the Tg of the polymerizing fluid exceeds the reaction temperature within the mold.

• Proceedings of the Korean Society of Rheology Conference
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• 2002.11a
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• pp.23-26
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• 2002

No Abstract, See Full Text

• Macromolecular Research
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• v.10 no.3
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• pp.135-139
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• 2002

Blends of the linear bisphenol-A polycarbonate (L-PC) and randomly branched bisphenol-A polycarbonate (Br-PC), prepared by co-rotating twin screw extrusion, were investigated using differential scanning calorimetry (DSC), sag resistance time tester, extensional rheometry, and advanced rheometric expansion system (ARES). From the DSC results, the glass transition temperature (T$_{g}$) of the L-PC/Br-PC blend was increased with the increase of Br-PC in the blend, and the blend showed a single T$_{g}$, which suggests a miscible blend. The sag resistance time of the L-PC/Br-PC blend was increased with the increase of Br-PC in the blends. From the results of rheological measurements of the L-PC/Br-PC blends, the extensional viscosity and the complex viscosity of the blends were found to increase with the increase of Br-PC in the blends. The increase of extensional viscosity and complex viscosity was related with the increase of sag resistance time with the Br-PC in the L-PC/Br-PC blends.nds.