• Elastomers and Composites
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• 제51권2호
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• pp.93-98
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• 2016

The composites of EVA/EPDM including aluminum trioxide (ATH) as a fire retardant were manufactured for the purpose of improving low temperature property and flame resistance in the rubbery materials. The ratio of EVA to EPDM didn't affect the flame resistance of the rubber composites. The addition of ATH resulted in increase of the flame resistance. In the evaluation of the cold resistance, the increasing EPDM content showed enhancement of cold resistance in the composites due to increasing low Tg EPDM. It was found out that tensile strengths of the composites showed a maximum value at 100 phr of ATH by reinforcing effect, but a minimum value at 200 phr of ATH owing to slippage between the flame retardant by the external stress. In the measurement of solvent resistance in tetrahydrofuran, the increasing ATH content yielded enhancement of solvent resistance by reducing swelling of the composite, and increasing EPDM content also resulted from increase of the solvent resistance by reduction of polarizability as well as increase of crosslink in the composites.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 추계학술대회 논문집
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• pp.195-198
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• 1998

In this paper, the physical and the volume resistivity properties due to linear low density polyethylene(LLDPE)/ethylene vinyl acetate(EVA) blends are studied. In order to measure the volume resistivity properties. the micro electrometer is used, the range of temperature and applying voltage are 25 to 120[$^{\circ}C$], form 100 to 1000[V] respectively. From FT-IR spectrum, LLDPE blended with EVA shows an absence of carbonyl and ether groups. From the experimental result of the volume resistivity properties, it is confirmed that the volume resistivity is decreased, which was attributed to the increase of molecular motions with the increase of temperature.

• 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.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.495-498
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• 2005

It was investigated the durability of the concrete to improve construction materials with polymer cement mortar in this study. With the popularity of repair and rehabilitation material, some mixtures composed of Ethylene Vinyl Acetate(EVA) was studied. Ethylene Vinyl Acetate(EVA) carried out tests to determine its properties which a include: freezing-thawing resistance test, carbonation test, and chemical resistance test. Result of freezing-thawing resistance test, mass change ratio and chemical resistance test, mass change ratio decreased of 12 and $15\~45\%$ as compared with control mortar. Carbonation depth decreased $3.7\~5.6mm$ as polymer-cement ratio increased $1\~4\%$.

• 한국포장학회지
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• 제16권1호
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• pp.5-7
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• 2010

Two kinds of polymer coating (acrylic polymer and vinyl acetate ethylene copolymer) added with 5% nisin were fabricated on the paperboards and tested in their antimicrobial activity against Micrococcus flavus ATCC 10240 inoculated into water contacting the coating at $10^{\circ}C$. Vinyl acetate ethylene copolymer giving faster and higher nisin migration presented the greater reduction in the microbial count than the other coating, which endorsed that the migrated nisin is mainly responsible for the microbial inhibition or destruction. There was also a slight effect of the coating polymer itself in the microbial inhibition.

• Elastomers and Composites
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• 제51권1호
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• pp.63-67
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• 2016

Poly(ethylene-co-vinyl acetate) (EVA) was pyrolyzed to eliminate acetic acid of VA unit using off-line pyrolysis, and the deacetylated EVA was analyzed infrared spectroscopy (IR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). EVA film for deacetylation was prepared by solution casting on aluminum foil and it was pyrolyzed at low temperature of $300^{\circ}C$ in the off-line pyrolysis apparatus. After deacetylation, carbon-carbon double bond (C=C) was formed by 1,2-elimination of the VA unit in the EVA backbone. Most of C=C bonds were trans-1,4-unit and 1,2-unit was also observed. Presence of the 1,2-unit in deacetylated EVA indicates that terminal or branch VA units exist in the raw EVA. Py-GC/MS chromatogram of deacetylated EVA displayed much smaller acetic acid and much more abundant other pyrolysis products than that of raw EVA, which means that the pyrolysis efficiency and separation condition were improved.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.556-559
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• 1999

In order to investigate the influence on dielectric characteristic due to physical structural change of specimens, we investigated the frequency and temperature dependency of tan $\delta$ for virgin specimen and mixtured specimens in the temperature range of 25[$^{\circ}C$] ~ 120[$^{\circ}C$], frequency range of 300(mv) ~ 1500[mV] An experimenatal specimen is selected as Low Liner Density Polyethylene (LLDPE) and Ethylene Vinyl Acetate(EVA) (thickness 200[$\mu$m]) produced by mixture ratio of 50:50, 60:40, 70:30 and 80:20. From the results of XRD it can be confirmed that the peak of LLDPE and EVA made by mixture ratio of 70:30 at 2$\theta$= 21.4$^{\circ}$is higher and the peak made by amorphous contribution at 2$\theta$= 19.5[$^{\circ}$] is almostly constant without no concern.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
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• pp.552-555
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• 1999

In this paper, the volume resistivity properties due to mixture ration of linear low density polyethylene(LLDPE) and ethylene vinyl acetate(EVA) are studied. Electrodes is composed of upper electrode 37(mm $\Phi$), guardring electrode(inner 55(mm $\Phi$ ), and lower electrode 87(mm $\Phi$ In order to measure the leakage current, We used electrometer and stable oven with temperature controller. Measurement method is to measure the leakage current of next specimen after applying the voltage according to 'Step Apply Methods' for ten minutes. In order to measure the volume resistivity properties, the micro electrometer is used, the range of temperature and applying voltage are 25 to 100[$^{\circ}C$] to 100[V] respectively.

• 폴리머
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• 제38권2호
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• pp.225-231
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• 2014

고분자 결합제로 vinyl acetate(VA) 함량이 각각 30, 60%인 poly(ethylene-co-vinyl acetate)(EVA)를 사용하여 고농축 복합화약 시뮬란트의 유변학적 특성을 연구하였다. 충전제로는 탄산칼슘 및 research department explosive (RDX)와 물리적 특성이 유사한 Dechlorane을 사용하였다. 회분식 용융 혼련기를 사용하여 농축 현탁계를 혼련하였는데 최대 75 v%까지 충전이 가능하였다. 동적 기계적 물성 변화를 측정한 결과 Dechlorane이 탄산칼슘보다 결합제수지와 더 높은 상호작용을 보였다. 일정 전단속도 방식과 일정 전단응력 방식의 평판-평판 레오미터를 사용하여 현탁계의 미세구조의 변화가 유변물성에 미치는 영향을 조사하였고, Krieger-Dougherty 식을 사용하여 최대 충전 부피분율 및 고유점도를 구하였다. EVA31/Dechlorane 현탁계의 최대 충전 부피분율은 약 70 v%이고, 혼련시 전단응력이 약 2000 Pa 정도 부가되는 것이 적절함을 알 수 있었다.