• Proceedings of the Korean Fiber Society Conference
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• 1998.04a
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• pp.36-39
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• 1998

플루란은 글루코스 삼량체인 말토트리오스(maltotiose)를 반복단위로 하고, 그 삼량체와는 다른 결합인 $\alpha$-1,6결합에 의해 반복결합한 고분자 선상 중합체이다(Fig. 1) 플루란은 검정색 효모인 aureobasidium pullulans에 의해 배양 생산된 천연 다당류의 일종이다. 플루란은 원료가 저렴하기도 하지만 플루란으로 만들어진 막, 필름(1), 섬유(2) 등의 일반적인 성형물은 투명성, 강인성, 산소 불투과성이 있으며 땅속 수중에서 자연 분해되며 소각에 의해 유독가스와 고엽이 발생하지 않으므로 공해를 동반하지 않는다.(중략)

• Polymer(Korea)
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• v.34 no.2
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• pp.166-171
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• 2010

Poly(N-isopropylacrylamide)(PNIPAAm) containing polydimethylsiloxane(PDMS) block and nano clay was obtained by the polymerization of NIPAAm and [3-(methacryloylamino)propyl]trimethyl ammonium montmorillonite(MAPTAC-MMT) with PDMS-macroinitiator. The polymer was characterized with FT-IR, XRD and DSC. The addition of PDMS in the polymers did not affect the value of the lower critical solution temperature(LCST) and the glass transition temperature($T_g$) of the PNIPAAm. However, the swelling ratio decreased with increasing PDMS contents. In the case of PNIPAAm containing nano clay, the content of MAPTAC-MMT did not affect swellability, but the $T_g$ of the PNIPAAm decreased with increasing nano clay contents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.1
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• pp.35-41
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• 2008

The purpose of this study was to investigate the effects of Chungkookjang viscous biopolymer supplementation on blood glucose and serum lipid-lowering in Streptozotocin (STZ)-induced diabetic rats. The rats were divided into three experimental groups; a normal group (N), diabetic control group (D), and a diabetic group with the supplementation of Chungkookjang viscous biopolymer (DCB). The groups were given experimental diets for four weeks. The normal group (C) was fed a casein-based diet, and the Chungkookjang viscous biopolymer group (DCB) received 3% biopolymer added to the casein-based diet. In the diabetic group (D), food intake increased significantly, but weight gain decreased significantly. The food efficiency ratio was significantly lower in the diabetic group. Liver weight increased significantly in the D group as compared to the N group. However, the DCB group showed a significant decrease in liver weight when compared to the D group. Blood glucose decreased significantly in the DCB group after receiving the experimental diet for four weeks, as compared to the diabetic control (p<0.05). Serum triglyceride levels were significantly lower in the DCB group than in the D group, whereas HDL-cholesterol levels were significantly higher (p<0.05). Total cholesterol was decreased in DCB group, but there were no significant differences. Also, LDL-cholesterol level was not significantly different among the experimental groups. Hepatic triglyceride and cholesterol were lower in the DCB group with no significant differences among groups. These results indicate that dietary supplementation of Chungkookjang viscous biopolymer improved glucose lowering and lipid metabolism in diabetic rats.

• Journal of Ocean Engineering and Technology
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• v.16 no.4
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• pp.1-6
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• 2002

Experimental investigation of drag reduction by adding a polymer additive(polyacrylamid, N-401P) into water is carried out in a Circular Water Channel. The effect of viscosity, surface roughness and degradation as a function of running time is also measured with varying the concentration of polymer additives(20ppm,100ppm) and Reynolds numbers. Near and far wakes past a circular cylinder are observed by LDV. Drag forces are measured with a strain-gaged device. The experimental results show that around 5%-30% of drag reduction with the polymer solution are observed. The larger effects of drag reduction can be found at low range of Reynolds number, more roughened surface cylinder. The effect of polymer solution for near wakes is larger than for far wakes.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.226-231
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• 1998

Hot melt adhesive which is solventless type has been widely used due to the possibility of automated adhesion process. The main purpose of this study is the development of polyamide based hot melt adhesive to improve the property of conventional ethylene-vinyl acetate hot melt adhesive, which has an inherent problem against heat resistance. In this study, it was found that the terpolymers of nylon 6, nylon 66, and nylon 12(CM831, 843P types) instead of nylon homopolymer were suitable base resins for hot melt adhesive, since the disruption of regularity in the polymer chains reduced the crystallinity, resulting in lower melting point and melt viscosity. According to the results, the optimum adhesion property could be obtained by the using 75/25~50/50 weight radio of CM831/843P resin as a base resin. Terpene resin was used as tackifier to improve adhesion and wetting properties. The best result can be obtained with the 10 wt.% addition of terpene resin. The terpene resin acted as proper tackifier in this system which decreased the melt temperature and viscosity, but increased the mechanical strength of adhesive itself. Also, the rheological property of the adhesive changed from typical non-Newtonian behavior to Newtonian behavior as terpene resin was added.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.348-354
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• 1998

Cellulose grafted with acrylic acid(AAc) was prepared by radiation grafting technique. The effects of reaction temperature. reaction time, monomer concentration, and the crosslinkers on the AAc grafting reaction on cellulose were examined. The amount of AAc grafted on the cellulose reached maximum at the concentration of 0.75vol% difunctional crosslinker and 1.0vol% trifunctional crosslinker, respectively. In the presence of acid, the amount of AAc grafted on the cellulose was decreased when reaction solution contains difunctional crosslinker, while that was increased when reaction solution contains trifunctional crosslinker. In the grafting reaction of cellulose with AAc and TMETA, mixture containing ferrous sulfate and acid enhanced further AAc grafting yield than mixture containing ferrous sulfate only.

• KSBB Journal
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• v.11 no.4
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• pp.420-430
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• 1996

One-step immuno-chromatography assay system for heat-killed Salmonella typhimurium antigens was developed. Three major components used were a glass fiber membrane (placed at the bottom of the system) with an antibody (specific to the analyse, detection antibody)-gold conjugate deposited in a dry state on the surface, a nitrocellulose membrane (middle) with an antibody (also, specific to the analyse but recognized different epitome: capture antibody) and anti-detection antibody immobilized in spatially separated areas, and a cellulose membrane (top) as absorption pad. These membranes were partially superimposed such that a wicking of aqueous solution containing sample can continuously take place through membranes. Variables that affected the system performance were the concentration of capture antibody, the location on the membrane, inert protein used for blocking of the membrane and for carrying the sample, and the concentration of the gold conjugate. Under optimal conditions, within 15 minutes after absorption of a sample solution from the bottom of the system antigen-antibody complexes of sandwich type were formed on the membrane surface area with immobilized capture antibody and a color signal was generated in proportion to the analyse concentration. The minimum do tection limit of the analyse was $1{\times}106$ Salmonella cells/mL.

• Journal of the Korean Chemical Society
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• v.45 no.2
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• pp.138-160
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• 2001

In this study we measured oxidation potentials and current densities for poly(vinylcholride) (PVC) and poly(carbonate)(PC) in nonaqueous solutions, in order to find out how corrosion (oxidation) potentials depend on temperature, pH, enzyme, or added salts. The Tafel's slopes were determined from the Tafel plots of polarization curves. The transfer coefficients (${\alpha}$) wre evaluated from the slope(1-${\alpha}$)nF/2.3 RT, and the electrode reactions appeared irreversible under all conditions.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.183-184
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• 2003

Poly(lactic acid) (PLA) is a highly versatile, biodegradable, aliphatic polyester derived from 100% renewable resources, such as corn and sugar beets. Because of the degradation mechanism, PLA is ideally suited for many applications in the environment where recovery of the product is not practical, such as agricultural mulch films and bags. Composting of post consumer PLA items is also a viable solution for many PLA products. (omitted)

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.495-497
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• 2017

Thermoplastic propellants using thermoplastic elastomer binders show moderate performance and mechanical properties compared to thermoset propellants, but these propellants are widely used in a variety of fields due to low cost of raw materials, simple manufacturing process and stable handling process. In order to utilize thermoplastic solid propellants in various fields, we will study properties depending on the content of oxidants, metal fuels and additives.