• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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• pp.218-222
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• 2002

In the recognition of the gases using the quartz crystal microbalance (QCM) coated with the PEG film materials, it is important to obtain the recognition ability of gases, and the stability of PEG film coated above the QCM. Especially, the thickness of PEG film coated above the QCM is decreased according with the using circumstance and time of QCM gas sensor. Therefore, the sensing characteristics of PEG film is changed with these. In this paper, we coated the PEG materials varing with the blended amount of PVC(Poly Vinyl Chloride) and chloroform above QCM to obtain the sensitive and the stability of PEG film. We measured the degradation characteristics of QCM gas sensor in the ethyle acetate 50[%] concentration to show the properties of stability.

• 한국응용과학기술학회지
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• 제17권4호
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• pp.262-266
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• 2000

Acrylic pressure sensitive adhesives of n-butyl acrylate, 2-ethyl acrylate, methyl acrylate, vinyl acetate, acrylic acid, acrylonitrile and 2-hydroxyethyl acrylate were synthesized and basic physical properties of pressure sensitive adhesives with increasing the contents of 2-hydroxyethyl acrylate were investigated. 2-Hydroxyethyl acrylates effects on glass transition temperature, viscosity, hardening time and peel strength. Glass transition temperature(Tg) decreased with increasing the contents of 2-hydroxyethyl acrylate. Viscosity and hardening time were increased with increasing the contents of 2-hydroxyethyl acrylate. On the other hands, peel strength increased with increasing the contents of 2-hydroxyethyl acrylate up to 6 wt% and the decreased at further higher contents of 2-hydroxyethyl acrylate. In peel test, interfacial failure was occured in 8 wt% and 10wt%.

• Bulletin of the Korean Chemical Society
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• 제26권1호
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• pp.38-42
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• 2005

Bis(2-methylbenzaldehyde)butane-2,3-dihydrazone(TDSB) was used as new N-N Schiff's base which plays the role of an excellent ion carrier in the construction of a La(III) membrane sensor. The best performance was obtained with a membrane containing, 30% poly(vinyl chloride), 60% benzyl acetate, 6% TDSB and 4% sodium tetraphenyl borate. This sensor reveals a very good selectivity towards La(III) ions over a wide variety of cations, including alkali, alkaline earth, transition and heavy metal ions. The proposed electrode exhibits a Nernstian behavior (with slope of 19.8 mV per decade) over a wide concentration range (1.0 ${\times}$ 10$^{-5}$-1.0 ${\times}$ 10$^{-1}$ M). The detection limit of the sensor is 7.0 ${\times}$ 10$^{-6}$ M. It has a very short response time, in the whole concentration range ($\sim$5 s), and can be used for at least twelve weeks in the pH range of 3.0-9.4. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a La(III) solution, with EDTA. It was also successfully applied in the determination of fluoride ions in three mouth wash preparations.

• 펄프종이기술
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• 제46권6호
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• pp.50-55
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• 2014

An oxidized starch was modified for surface sizing via etherification and esterification. Propylene oxide (PO), sodium monochloroacetate (SMCA), and acrylonitrile (AN) were used as etherification, and vinyl acetate monomer (VAM), maleic anhydride (MA), fumaric acid (FA), and itaconic acid (ITA) were used for esterification. Esterification and etherification of starch decreased both Brookfield viscosity and Brabender viscosity substantially even though the solids level was increased by 2% from 14 to 16%. Surface sizing performance of starches in tensile strength, stiffness and compressive strength was improved by esterification and etherification of the oxidized starch. Especially, SMCA etherification was found to be the most effective modification method.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.31-35
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• 2011

Photovoltaic modules are well known to be one of the most eco generation of electricity. But usually study solar cell. Otherwise, PV modules are also important in power generation. We have to check other subsidiary materials. In this work benefit of using optically superior encapsulation materials(EVA) in generation temperature is demonstrated. Optical characterization of three EVA products demonstrates reduced transmission in the visible ray region of the solar spectrum. It will have a decisive effect to the module efficiency. Test is shown reduction of reflectance and transmittance. Reflections is dependent on the low iron glass. It can be seen between a specific wave length(240~350mm) about 1%. Transmittance in the entire ray region of light is markedly reduced to depending on the temperature rise. The graph is shown optical properties on EVA. Transmission was reduced. about 1%.

• Transactions on Electrical and Electronic Materials
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• 제7권6호
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• pp.309-312
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• 2006

This study shows to blend ethylene vinyl acetate(EVA) and a flame retardant agent, $Mg(OH)_{2}$, and synergists, zinc borate for improving flame retardancy of low density polyethylene(LDPE). And it studied the property of flame retardancy of LDPE/EVA blend by the amount of addition through LOI and TGA, estimated the electrical characteristics such as volume resistivity and breakdown strength. The flame retardancy of LDPE/EVA blend was much improved in case of adding zinc borate with 6phr degree, and the electrical characteristics were more or less decreased depending on increasing the amount of addition. Zinc borate used for improving the flame retardancy of LDPE/EVA blend let the added amount of a flame retardant agent, $Mg(OH)_{2}$ limited, and the electrical characteristics decreased extremely by adding a good deal of $Mg(OH)_{2}$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기물성,응용부문
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• pp.28-29
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• 2006

To improve Mechanical and Thermal Properties of semiconducting materials in power cable, we have investigated those of semiconducting materials showed by changing the content of carbon black and Carbon Nanotube. Density were measured by EW-200SG. High temperature, heat degradation initiation temperature, and heat weight loss were measured by TGA (Thermogravimetric Analysis). The dimension of measurement temperature was $0[^{\circ}C]$ J to $700[^{\circ}C]$, and rising temperature was $10[^{\circ}C/min]$. Heat degradation initiation temperature from the TGA results was decreased according to increasing the content of Carbon Nanotube. That is, heat stabilities of EVA containing the weak VA (vinyl acetate) against heat was measured the lowest. From the results of the experiment applied in this study, it is evident that a small amount of Carbon nanotube additives significantly improved the Mechanical and Thermal Properties of semiconducting materials.

• 한국의류산업학회지
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• 제10권3호
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• pp.371-376
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• 2008

Poly(ethylene-co-vinylacetate) (EVA) microspheres were prepared by thermally induced phase separation (TIPS) in toluene. The microsphere formation occurred by the nucleation and growth mechanism in metastable region. The effects of the concentration and component of the polymer and cooling rate on microsphere formation were investigated. The microsphere formation and growth were followed by the cloud point of the optical microscope measurement. The microsphere size distribution, which was obtained by particle size analyzer, became broader when the polymer concentration was higher, the content of vinyl acetate in EVA copolymer was higher, the cooling rate of EVA copolymer solution were lower. The content of disperse dye in EVA microsphere was obtained by TGA thermal analysis, the dye content of EVA15 and EVA18 were 3.5 and 2.0 wt% respectively.

• 산업기술연구
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• 제30권A호
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• pp.37-43
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• 2010

Polymeric materials in addition to Portland cement and hydrated limes were used to solidify heavy metal contaminated tailings from five abandoned metal mines in Korea. Mine tailings were mixed separately with Portland cement and hydrated lime at a concentration of 20-30 wt% and 6-9 wt%, respectively and Ethylene Vinyl Acetate(EVA) powder was added to each specimen at a ratio of 2.5 and 5.0 wt% to binders. Polymer-added and polymer-free solidified forms were evaluated for their appropriateness in accordance with the suggested test methods. Regardless of addition of polymeric materials, all solidified forms satisfy the uniaxial compressive strength(UCS) requirements(0.35MPa) for land reclamation and show remarkably reduced leaching concentrations of heavy metals such as As, Cd, Cu, Pb and Zn less than the toxicity criteria of Korean standard leaching test(KSLT). The addition of polymeric materials increased the UCS of solidified forms to improve a long-term stability of solidified mine tailings.

• 폴리머
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• 제32권3호
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• pp.219-229
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• 2008

A pH sensitive ternary copolymer gel was synthesized in the presence of ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent through radical polymerization of vinyl acetate (VA), acrylic acid (AA) and methyl acrylate(MA) with a weight ratio of 1 : 1.3 : 1. A number of experiments were carried out to determine the swelling behavior of the gel under a variety of pH conditions of the swelling medium. As the pH of the swelling medium was changed from 1.0 to 8.0 at $37^{\circ}C$, the gel showed a shift in the pH-dependent swelling behavior from Fickian (n=0.3447) to non-Fickian (n=0.9125). The resulting swelling parameters were analyzed using graphical and statistical methods. The results showed that the swelling of the gel was controlled by the pH of the medium, i.e. $n=n_o{\exp}(S_{C}pH)$, where n is the diffusion exponent, $n_o(=28.9645{\times}10^{-2})$ is the pre-exponential factor and $S_C$(=0.1417) is pH sensitivity coefficient. The swelling behavior of the gel was also examined in aliphatic alcohols. The results showed that the rate of swelling increased with increasing number of carbon atoms in the alcoholic molecular chain.