• 반도체디스플레이기술학회지
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• 제18권1호
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• pp.42-47
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• 2019

The four different polymer compounds were manufactured to make cable sheath for ship industry. Two kinds of ethylene-vinyl acetate (EVA) were selected as main matrix polymers for compounding with fire retardant, crosslinking agent, filler, plasticizer, and other additives. The properties of the four compounded materials were investigated with the contents of fire retardant, silane coated aluminum hydroxide (S-ATH). Rheology, Mooney viscosity, and tensile strength increased with S-ATH contents by reinforcing effect. With increasing fire retardant amount, fire resistance increased, but cold resistance didn't show an obvious enhancement due to polar effect of vinyl acetate in EVA.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.424.1-424.1
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• 2016

태양전지 모듈의 봉지재로 사용되는 EVA(Ethylene-Vinyl acetate)는 외부의 환경으로부터 태양전지를 보호해주는 역할을 한다. 하지만 frame의 실링재나 glass edge 부분의 결함으로 인해 수분이 침투되어 모듈의 내부자재에 영향을 미치게 되며, 모듈의 효율 감소나 수명 단축의 원인이 된다. 이러한 결함을 줄이기 위해서는 EVA의 crosslinking degree, 절연 저항 특성을 향상시키는 것이 중요하다. 이에 본 연구에서는 EVA의 crosslinking degree를 보기 위해 soxhlet extraction method를 이용하여 gel content를 측정하였으며, 라미네이션 과정 중 curing time에 따른 gel content 변화를 확인하였다. 또한 이 실험을 바탕으로 gel content에 따른 절연 저항을 측정하여 EVA의 crosslinking degree에 의한 절연 저항 특성을 확인하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
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• pp.92-97
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• 2008

To survive in outdoor environments, photovoltaic modules rely on packaging materials to provide requisite durability. We analyzed the properties of encapsulant materials that are important for photovoltaic module packaging. The properties of Ethylene Vinyl Acetate(EVA) sheet in photovoltaic encapsulant materials have to meet conditions that are high optical transmittance, good adhesion and high cross-linking rate. The objective of this paper is to understand the property evaluation methods of EVA sheet. Through this research, we could confirm that properties of EVA sheet have an effect on durability and operating efficiency of photovoltaic module.

• Journal of Pharmaceutical Investigation
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• 제25권3호spc1호
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• pp.53-59
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• 1995

Ethinylestradiol (EE)-containing matrix was fabricated with ethylene-vinyl acetate(EVA) copolymer to control the release of the drug, Effect of addition of PEG 400 as receptor solution, the stripping of skin and Azone pretreatment on skin on the permeation of EE through the excised mouse skin was also studied. The permeation rate of EE through the excised mouse skin was affected by the PEG 400 volume fraction. The Azone pretreatment on skin didn't affect on the steady state flux, however, the lag time was shortened. The permeation rate of EE through the stripped skin was much larger than that through the whole skin. It showed that the stratum corneum acts as a barrier of skin permeation. The fact that there is little difference in EE permeation between the intact skin and the stripped skin with EVA membrane shows the permeation of EE through the mouse skin is mainly controlled by the membrane.

• 자원리싸이클링
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• 제20권6호
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• pp.50-55
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• 2011

태양전지(Photovoltaic, PV) 모듈의 층간 접착제로 사용된 EVA(Ethylene Vinyl Acetate)를 초음파 조사(irradiation)를 이용하여, 선택적으로 분해함으로써 모듈 내 실리콘웨이퍼(Si-wafer)로 제조된 셀(cell)을 분리, 회수하는 연구를 진행하였다. 본 실험에 사용한 초음파 발생장치는 bath-type의 초음파 세척기 (Output: 130 W, Frequency: 40 kHz)로, PV모듈과의 거리는 2 cm로 고정하고 유기용매 종류, 농도, 온도를 조절하면서 EVA 분해 및 셀의 분리 최적 조건을 도출하였다. $55^{\circ}C$, 5M인 조건에서는 용매 종류에 상관없이 160 min 이내에 EVA층의 완전 분해는 가능하였으나, 분해과정 중 발현되는 팽창현상(swelling)에 의해 셀의 일부분이 파손된 상태로 회수되었다. 반면에 $65^{\circ}C$, 5M조건에서는 셀의 파손이 억제된 상태로 회수 가능하였으며, 이는 온도 상승에 의해 EVA 성분의 분해속도가 상승되고, 이로 인해 EVA층의 팽창현상이 발현되기 전에 분해가 일어난 결과라고 판단된다.

• Elastomers and Composites
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• 제36권1호
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• pp.52-60
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• 2001

발포체의 물성은 발포체의 밀도, 사용된 폴리머의 기계적 물성과 열린 셀(open cell) 함량, 셀 크기, 셀 크기 분포, 셀 형태, 격벽의 두께 등을 포함하는 셀 구조에 의존하며 이러한 발포체의 밀도는 사용된 폴리머의 종류와 가교제의 농도, 발포제의 농도 그리고 가공 기술 및가공 조건 같은 다양한 원료물질과 가교조건에 영향을 받는다. Ethylene vinyl acetate coplymer (EVA) 발포체는 가교 발포체로서 가교속도와 발포제의 분해속도에 의해 발포특성에 영향을 받으며 이에 따라 발포체 물성에도 영향을 미친다. 본 연구에서는 가공 온도인 $155^{\circ}C$에서의 시간에 따른 발포제의 분해 속도 차이와 이에 따른 발포특성과 발포체의 물성에 대한 영향을 평가하였다. 발포제 분해 속도가 보다 느린 경우, 발포제 분해속도가 빠른 경우와 비교하여 낮은 밀도를 보여주었으며, 우수한 충격흡수성을 나타내었고 발포체의 셀 크기는 보다 균일하였다.

• 방사선산업학회지
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• 제17권4호
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• pp.369-375
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• 2023

Radon, a carcinogenic substance generated from soil or building materials, have to be fundamentally blocked from entering indoors. In this study, ethylene vinyl acetate (EVA)/silicone emulsions with excellent mechanical and thermal properties and effective blocking of radon gas were prepared by using radiation technology. As the electron-beam irradiation does increased, a partially crosslinked structure was formed in EVA molecular chain, increasing tensile properties and adhesive strength. The EVA/silicone film showed excellent thermal stability without deformation. In addition, the non-irradiated EVA/silicone film showed a radon blocking rate of about a 75%, while the EVA/silicone film irradiated with 3 and 5 kGy showed an excellent radon blocking rate of over 90% due to the formation of crosslinked structure in the EVA molecular chain. These results indicated that the radiation technology can effectively block radon by forming a partially crosslinked structure of EVA/silicone emulsion to improve tensile property, adhesive strength, and deformation stability.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.78-83
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• 2001

In this work, the surface of inorganic fillers were modified with some functional groups such as stearic acid, aliphatic long chain, vinylsilane and aminosilane to control the interaction between inorganic fillers and polymer matrix. Ethylene-vinyl acetate copolymers (EVA) with various amount of vinyl-acetate content and copolyether-ester elastomer were used as polymer matrix. The addition of inorganic fillers increases flame retardancy, but results in steep drop of electrical and mechanical properties, which may be caused by the defect in the interface between organic/inorganic hybrid composites. The hybrid composites are found to show better mechanical properties and higher volume resistivities as inorganic fillers are well dispersed and have good adhesion with polymer matrix. Also, the most effective type of functional group coated on fillers depends on the chemical structure of polymer.

• Elastomers and Composites
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• 제51권3호
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• pp.206-211
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• 2016

Experimental error sources for thermogravimetric analysis (TGA) of poly(ethylene-co-vinyl acetate) (EVA) were investigated and sample preparation method to reduce the experimental error was suggested. Maximum dissociation temperatures of EVA for the first and second dissociation reactions ($T_{m1}$ and $T_{m2}$, respectively) were measured. By decreasing the weight of raw EVA, the $T_{m1}$ increased but the the $T_{m2}$ decreased. When weight of the raw EVA was over 10 mg, the TGA curve showed abnormal behaviors. The abnormal TG behaviors were explained by gathering and instantaneous evaporation of acetic acid formed by deacetylation of the VA unit. When TGA analysis of EVA was performed using untreated (raw) EVA, the experimental errors were about 1%. In order to eliminate the abnormal TG behaviors and to reduce the experimental errors, EVA film made by solvent casting was used. For the treated EVA (EVA film), the abnormal TG behaviors did not appear, the $T_{m1}$ decreased by about $2^{\circ}C$ but the $T_{m2}$ increased by about $6^{\circ}C$, and the experimental errors were reduced by 0.5%.

• Journal of Pharmaceutical Investigation
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• 제40권3호
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• pp.167-173
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• 2010

Repeated oral administration of hydrochlorothiazide, a loop diuretic, due to transient high blood levels, may cause adverse effects such as gastric disturbance, nausea, high blood sugar, and hyper lipidemia. Transdermal administration could avoid some of these systemic side effects and gastric disorders. We have developed a matrix using ethylene-vinyl acetate (EVA), a heat-processible and flexible material, for transdermal delivery of hydrochlorothiazide. Drug solubility was highest at 40% PEG-400 volume fraction. Drug release increased as concentration increased with a linear relationship between the release rate and the square root of loading dose. Increasing temperature increased drug release from the EVA matrix. The activation energy, measured from the slope of log P versus 1000/T, was 11.9 kcal/mol for a 2.5% loading dose from EVA matrix. Diethyl phthalate had the highest plasticizing effects on the release of hydrochlorothiazide. To increase the skin permeation of hydrochlorothiazide from the EVA matrix, enhancers such as the saturated fatty acids, the unsaturated fatty acids, and the non-ionic surfactants were added to the EVA matrix, and skin permeation was evaluated using a modified Keshary-Chien diffusion cell fitted with intact excised rat skin. Polyoxyethylene 23-lauryl ether showed the highest enhancing effects. In conclusion, transdermal delivery of hydrochlorothiazide could be improved from an EVA matrix containing plasticizer and permeation enhancer.