• 비파괴검사학회지
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• 제25권5호
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• pp.368-376
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• 2005

자동차용 냉각기 호스는 열과 기계적 하중 하에서 공기와 부동액의 접촉 스트레스로 인해 노화와 고장이 일어날 수 있다. 본 연구에서는 냉각기 호스재료인 EPDM(ethylene-propylene diene monomer)고무에 대해 열가속 및 산소 스트레스, 전기화학적 스트레스에 의한 표피층의 노화거동을 비파괴 평가하였다. 열가속 및 산소노화 시험결과 신장률의 저하와 함께 IRHD(International Rubber Hardness Degrees)경도가 증가하였다. 전기화학적 노화(electro-chemical degradation: ECD) 시험에서는 에틸렌글리콜 수용액의 침투로 인해 무게가 증가하였으며 신장률과 경도는 크게 저하되었다 또한 에틸렌글리콜 수용액이 표피층뿐만이 아니라 내부에까지 침투하여 고무내부구조와 미크로경도분포가 깊이에 따라 변화되었다. 즉, 열가속 및 산소노화와 ECD 노화는 미크로 경도와 화학구조분석에 의해 비파괴적 특성 평가가 가능함을 보였다.

• 폴리머
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• 제29권2호
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• pp.166-171
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• 2005

EPDM(ethylene propylene diene monomer)1실리콘 고무 블렌드를 제조하고, 상용화제와 열노화 시간에 따른 물성 변화를 살펴보았다. EPDM과 실리콘 고무(SR)의 조성비는 90/10에서 $10/90\;wt\%$ 사이로 조절하였으며, Brabender사의 Plasticoder를 사용하여 용융 혼합하고, 열프레스로 가교하였다. 가교된 EPDM/SR 블렌드의 모폴로지를 주사전자현미경으로 관찰하였다. 또한, 블렌드를 $100^{\circ}C$에서 24, 48, 96시간 동안 열노화시켜 경도, 인장 강도, 신장률 및 접촉각을 측정하였다. 모폴로지를 조사한 결과 상용화제를 첨가한 블렌드의 분산상의 크기가 감소하였다. 열노화 시간이 증가함에 따라, 블렌드의 경도와 인장 강도는 감소하였으며, 신장률과 접촉각은 증가하였다.

• 한국결정성장학회지
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• 제25권5호
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• pp.193-198
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• 2015

본 연구에서는 전자파 차폐형 MCT(multi cable transit)의 인서트블록에 사용되는 유연성 EPDM(ethylene propylene diene monomer)고무 상에 무전해 도금을 이용하여 니켈도금을 실시하였다. 도금욕의 공정변수 조절 즉 pH 및 온도에 따라 Ni 도금층의 결정성 및 부착력이 결정되었다. pH와 온도를 달리하여 합성 한 결과 pH 7 및 8, $60{\sim}70^{\circ}C$에서 얻은 도금막들에서 잘 발달된 결정상과 높은 전기 전도도를 가짐을 알 수 있었다. pH 7, $70^{\circ}C$에서 도금 시 가장 높은 부착력 및 전기전도도를 얻을 수 있었으며, 또한 400 MHz~1 GHz 범위에서 우수한 전자파 차단능을 얻을 수 있었다.

• Nuclear Engineering and Technology
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• 제43권3호
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• pp.279-286
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• 2011

The aging degradation and lifetime assessment of a domestic class 1E Ethylene-Propylene-Diene-Monomer (EPDM), which is a popular insulating elastomer for electrical cables in the nuclear power plants, were studied for equipment qualification verification under the Loss of Coolant Accident (LOCA) conditions. The specimens were acceleratively aged, underwent a LOCA environment, as well as tested mechanically, thermo-gravimetrically, and spectroscopically according to the American Society of the Testing of Materials (ASTM) procedures. The tensile test results revealed that the elongation at break gradually decreased with an increasing aging temperature. The lifetime of EPDM aged isothermally at $140^{\circ}C$ was 1,316 hours and reduced to 1,120 hours after experiencing the severe accident test. The activation energies of the elongation reduction were $1.10{\pm}0.196$ eV and $0.93{\pm}0.191$ eV before and after the LOCA condition, respectively. The TGA test results also showed that the activation energy of the aging decomposition decreased from 1.35 eV to 1.02 eV after undergoing the LOCA environment. Although the mechanical property changes were discernibly observed during the aging process, along with the LOCA simulation, the FT-IR analysis showed that the spectroscopic peaks and their intensities did not alter significantly. Therefore, it can be concluded that the degradation of the domestic class 1E EPDM due to aging can be tolerable, even in severe accident conditions such as LOCA, and thus it qualifies as a suitable insulating material for electrical cables in the nuclear power plants.

• Elastomers and Composites
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• 제52권1호
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• pp.35-47
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• 2017

A comprehensive survey of the available literature showed that in the last few decades, there has been a growing interest in the use of thermoplastic vulcanizates (TPVs). TPVs are the second largest group of soft thermoplastic elastomers (TPEs) after styrene-based block copolymers, and offer a wide range of potential and proven applications, including in mechanical rubber goods, under-the-hood applications in the automotive field, industrial hose applications, electrical applications, consumer goods, and soft touch applications. Over the last two decades, TPVs have shown a strong and steady market growth (~12% per year). Commercialized TPVs are commonly based on blends of ethylene propylene diene monomer (EPDM) rubber and polypropylene (PP), and to a lesser extent on combinations of butyl or nitrile rubber with PP. EPDM/PP TPVs are characterized by finely dispersed crosslinked EPDM rubber particles (particles size varying between 0.5 and $2.0{\mu}m$) distributed in a continuous thermoplastic PP matrix. If the rubber particles of such a blend are small enough and if they are vulcanized well enough, then the properties of the blend are generally improved. This review article introduces various topics and aspects relevant to EPDM/PP TPVs. The development of TPVs, the use of various types of crosslinking systems and co-agents as crosslinking agents for PP/EPDM blends, the morphology and rheology of TPVs, and their typical end-use applications are also reviewed.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2000년도 추계학술대회논문집
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• pp.77-80
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• 2000

In order to determine what influences the interfacial charge in EPDM/XLPE laminates, We used PEA (pulsed electroacoustic) method. Interfacial properties such as space charge accumulation and breakdown strength in crosslinked polyethylene (XLPE)/ethylene-propylene-diene monomer (EPDM) laminates were investigated. Interfacial charge develops when the EPDM is laminated with XLPE. It showed the positive polarity same as the simulation in case on intercase of EPDM/XLPE. In case of coupling agent added silicone oil, as increasing the content of coupling agent, the interfacial charge decreased. Details of the results are given and their origins discussed.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.77-80
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• 2000

In order to determine what influences the interfacial charge in EPDM/XLPE laminates, We used PEA (pulsed electroacoustic) method. Interfacial properties such as space charge accumulation and breakdown strength in crosslinked polyethylene (XLPE)/ethylene-propylene-diene monomer (EPDM) laminates were investigated. Interfacial charge develops when the EPDM is laminated with XLPE. It showed the positive polarity same as the simulation in case on intercase of EPDM/XLPE. In case of coupling agent added silicone oil, as increasing the content of coupling agent, the interfacial charge decreased. Details of the results are given and their origins discussed.

• Composites Research
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• 제21권1호
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• pp.40-45
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• 2008

자동차용 유압브레이크 고무호스 어셈블리 제품은 자동차에 장착되어 실제로 사용 중에 가압, 굽힘, 비틀림, 열하중 등의 복합적인 스트레스를 받는다. 고무호스의 재질은 EPDM(ethylene-propylene diene monomer)고무와 PVA(polyvinyl acetate)섬유 보강층 그리고 중간고무로 NR(natural rubber)고무가 사용되고 있다. 고무호스 어셈블리 제품의 내구성과 파괴 메커니즘을 조사하기 위해 굽힘과 비틀림의 반복하중 사이클 수가 10만, 20만, 30만, 40만, 최종파열 사이클 수까지 되도록 시험하였다. 유압브레이크 고무호스의 초기크랙 발생을 알아보기 위해 제품 시험편을 다이아몬드 휠커터를 이용하여 수직 절단하여 폴리싱한 후 광학현미경과 주사형 전자현미경(SEM)으로 단면을 관찰하였다. 40만 사이클의 피로하중을 받은 시험편을 보면 외면고무와 PVA섬유 사이의 계면을 따라 길이 1mm의 층간분리가 일어났으며, 이러한 손상은 외면고무의 표피층으로 균열을 진전시켜 고무호스를 최종적으로 찢어지게 하는 것이다.

• 센서학회지
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• 제24권2호
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• pp.88-92
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• 2015

In order to study the semi-conductive characteristics of carbon black-filled ethylene-propylene-diene monomer (EPDM) composite film, which is used for measuring occlusal force, composite samples with volume ratios of carbon black to EPDM ranging from 30% to 70% were prepared. The process of making a composite film consists of two steps, which involve the preparation of a slurry composition and the fabrication of a thin film using solution casting and a lamination process. To prepare the slurry composition, we dispersed carbon black nanoparticles into an organic solvent before mixing with an EPDM solution in toluene. The mechanical and electrical properties of the resulting carbon black-filled EPDM film were then investigated, and the results showed that the electrical resistance of a film decreases with the increase in the carbon black content. Furthermore, improved elastic recovery was observed after cross-linking the EPDM.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.243-247
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• 2003

The effect of accelerated weathering(UV) on three type of ethylene propylene diene monomer(EPDM) composite used for higher voltage insulator were investigated by weather-emoter. For weatherability of EPDM composite, surface resistance, dielectric breakdown strength, change of contact angle, surface composition were measured according to UV accelerated weathering time. From the resort of the measurement of surface resistivity, contact angle of EPDM composite decreased and showed chalking and cracking phenomenon when UV weathweing time was for 1500 h and 2000 h. The analysis of surface atomic composition indicated that surface aluminiu(Al) content was detected due to chalking phenomenon after 1500 h of UV weathering, Oxygen content of all composite increased due to the oxidation.