• Journal of Pharmaceutical Investigation
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• v.19 no.4
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• pp.185-190
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• 1989

The release of angiotensin and ${\alpha}-amylase$ from monolithic devices of different molecular weight of polyethylene glycol (PEC) grafted polyurethane copolymer was investigated. Water-soluble PEG grafted polymer provided a controlled release of angiotensin and ${\alpha}-amylase$. The release rate of angiotensin and ${\alpha}-amylase$ could be controlled by varying the molecular weight of PEC grafted. The release mechanism may be associated with the creation of pore or domain through the devices following the gel swelling and self-aggregation by PEC grafted polymer. Hydrophobic polyurethane grafted with PEG can provide a biomaterial for prolonged release of angiotensin and ${\alpha}-amylase$ from angiotensin and ${\alpha}-amylase$ blended system.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.174-174
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• 2006

By condensing two different functional monomers, highly fluorescent aromatic polymers were prepared to produce a conjugated- conjugated spacer-type copolymer or conjugated-non-conjugated spacer-type copolymer. As synthesized polymers were soluble in an organic solvent and showed significantly enhanced optical properties compared to its monomer. Variation in the monomer composition afforded polymers having multifunctionaility such as photochromic-fluorescent polymers. Transparent thin films of the polymer as a solid medium were prepared using spin coating method and fabricated as a photoswitch, which showed photo-induced conductivity switching properties depending on the core monomeric unit in the polymers.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.133-134
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• 2006

In contrast to paints, the surface appearance of adhesive materials is of minor importance, because the adhesive is invisible between the two substrates. Therefore, the rheological properties needed to apply an adhesive dispersion by spray coating can be quite different. The influence of three different kinds of thickeners on the spraying behaviour of polyurethane adhesive dispersions was investigated. The associative thickener showed only minor changes, whereas the higher molecular weight soluble thickeners dramatically changed the spraying angle and the amount of overspray. Determination of the elongational viscosity by means of the CaBER rheometer proved to be of limited use for thickened dispersions.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.256-256
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• 2006

The design and synthesis of novel biomolecular materials, based on mimicking the properties of molecules found in nature, is providing materials with unusual properties. Resilin serves as an energy storage material in insects and facilitates flight, jumping (in fleas, froghoppers etc) and sound production (cicadas, etc). Resilin is initially produced as a soluble protein and in its mature form is crosslinked through formation of dityrosine units into a very large insoluble polymer. In the present study, we have synthesized a recombinant form of resilin that can be photochemically cross-linked into a resilient, rubber-like biomaterial that may be suitable for spinal disc implants. This material is almost perfectly elastic and its fatigue lifetime in insects must be >500 million cycles.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.181-186
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• 2008

2,5-Di-(2'-hydroxyethoxy)-4'-nitrostilbene (3) was prepared and polycondensed with terephthaloyl chloride, adipoyl chloride, and sebacoyl chloride to yield novel T-type polyesters (4-6) containing the NLO-chromophores dioxynitrostilbenyl groups, which constituted parts of the polymer backbones. Polymers 4-6 are soluble in common organic solvents such as acetone and N,N-dimethylformamide. They showed thermal stability up to 260 oC in thermogravimetric analysis with glass-transition temperatures obtained from differential scanning calorimetry in the range 90-95 oC. The second harmonic generation (SHG) coefficients (d33) of poled polymer films at the 1064 nm fundamental wavelength were around 1.42 ´ 10-9 esu. The dipole alignment exhibited high thermal stability up to 5 oC higher than glass-transition temperature (Tg), and there was no SHG decay below 100 oC due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.707-708
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• 2000

Colloidal gold with a conducting polymer (e.g., polyaniline) bound on the metal surfaces has been used for the generation of conductimetric signal in a membrane strip immunosensor. Since polyaniline itself at a low pH range revealed a low conductivity, an approach of doping the polymer with a lithium salt was used. As an alternative method, a self-doped (i.e., pH-independent) sustance such as leucoemeraldine base sulfonated polyaniline (LEB-SPAN) can be used as signal generator. It was also highly soluble in water and, thus, such a selected polymer was expected to support a satisfactory property as a label of the immunosensor.

• International Journal of Concrete Structures and Materials
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• v.3 no.2
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• pp.97-101
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• 2009

It has been known that acid-resistant concretes on the liquid glass basis have high porosity (up to 18${\sim}$20%), low strength and insufficient water resistance. Therefore they can not be used as materials for load-bearing structural elements. Significant increasing of silicate matrix strength and density was carried out by incorporation of special liquid organic alkali-soluble silicate additives, which block of superficial pores and reduces concrete shrinkage deformation. It was demonstrated that introduction of tetrafurfuryloxisilane additive sharply increases strength, durability and shock resistance of silicate polymer concrete in aggressive media. This effect is attributable to hardening of contacts between silicate binder gel globes and modification of alkaline component owing to "inoculation" of the furan radical. The optimal concrete composition with the increased strength, chemical resistance in the aggressive environments, density and crack resistance was obtained.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.424-430
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• 2011

A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-(5-(1,2,2-tricyanovinyl)-2-thienyl)ethenes as NLO chromophores, which constitute part of the polymer backbone, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It shows a thermal stability up to $270^{\circ}C$ from TGA thermogram with $T_g$ value obtained from DSC thermogram near $155^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer film at 1560 nm fundamental wavelength is $3.56{\times}10^{-9}$ esu. Polymer 7 exhibits a thermal stability even at $5^{\circ}C$ higher than $T_g$, and no significant SHG decay is observed below $160^{\circ}C$, which is acceptable for nonlinear optical device applications.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1219-1221
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• 1997

Poly(1,4-phenylene(1-methoxyenthylene)), organic water soluble PPV precursor was synthesized for polymer electroluminescence(EL) device. To control the molecular array, deposition method of emitter was Langmuir-Blodgett(LB). PPV precursor layer was treated thermally to conversion of PPV. Optical, electrical and EL properties of PPV LB thin film was estimated. Homogeneous light emission of greenish-yellow in PPV LB thin film can be easily confirmed under normal lighting even at low driving voltage. Polymer EL device using PPV LB thin film as emitter materials had a possibility to apply to next generation display device.

• Polymer(Korea)
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• v.26 no.5
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• pp.568-574
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• 2002

Inclusion compounds using cyclic poly(oxyethylene)s as host molecules have been used to polymerize pyrrole chemically in aqueous medium. This general synthetic strategy makes it possible to grow rigid aromatic polymers in aqueous medium by chemical oxidation method. It is an easy method to obtain rigid polymers in a very mild manner. Some threaded and water-soluble polypyrroles are obtained, and their characterization is performed by NMR, IR, UV, and MALDI-TOF MS measurements.