• Elastomers and Composites
• /
• 제36권3호
• /
• pp.169-176
• /
• 2001

2몰% 에틸가지를 포함하는 에틸 가지화 폴리에틸렌[(PE(2)]과 에틸렌-프로필렌 몰비가 50:50으로 같지만 입체규칙성이 서로 다른 랜덤-에틸렌-프로필렌 고무(r-EPR), 교호-에틸렌-프로필렌 고무(alt-EPR) 및 이소탁틱-교호-에틸렌-프로필렌 고무(iso-alt-EPR)를 에틸렌-프로필렌 고무의 입체규칙성에 대한 혼화성과 물성의 차이를 조사하기 위하여 혼합하였다. 이 세가지 블렌드들은 상온에서 상호간에 혼화성이 없었고, 밀도 측정에서 단순한 첨가 효과를 보여 주었다. 블렌드 조성에 따른 폴리에틸렌의 녹는점 감소는 PE(2)/r-EPR>PE(2)/alt-EPR>PE(2)/iso-alt-EPR의 순서로 증가하였다. 인장시험에서 이 블렌드계는 혼합 조성이 50:50 일때 가장 낯은 파난강도의 값을 보여 주어 이 블렌드 조성에서 두 고분자 상(phase)이 가장 분리된 형태학(morphology)을 가지고 있음을 알았다.

• 접착 및 계면
• /
• 제2권4호
• /
• pp.24-31
• /
• 2001

용융 흐름성이 다른 폴리프로필렌(Polypropylene, PP)을 에틸렌-프로필렌 고무(EPR) 또는 에틸렌-프로필렌-디엔 단량체 고무(EPDM) 및 카르복실산 그룹을 갖고 있는 에틸렌 공중합체와 이축 압출기로 용융 혼합한 후 사출성형으로 고분자 블렌드 시편을 제조하였다. 제조된 블렌드의 기계적 특성과 시편의 두께 방향에 따른 모폴로지 변화를 조사하였으며 적외선 분광법(ATR-IR)을 이용하여 표면에서의 카르복실산 그룹의 상대적 피크 크기를 비교하였다. 단면의 모폴로지 조사에서 중앙부에는 PP 연속상에 고무 도메인이 골고루 혼합되어 있지만 표면쪽은 PP가 층을 이루고 있는 경사구조가 관찰되었다. PP의 흐름성이 클수록 블렌드의 인장강도 및 충격강도가 작아졌으며 EPR보다 EPDM을 고무성분으로 사용한 PP계 블렌드가 PP의 흐름성에 대한 영향을 적게 받았다. 또한 PP의 흐름성이 클수록 카르복실산 그룹이 표면에 많이 존재하였다.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제3C권2호
• /
• pp.48-54
• /
• 2003

To evaluate the radiation degradation of ethylene propylene rubber (EPR), radiation effects on EPR were investigated by using dielectric analysis and thermal-gravimetric analysis. Permittivity, loss factor, tan$\delta$, and thermal decomposition temperature were observed for ${\gamma}$-ray irradiated EPR. As the radiation dose was increased, the peak temperature of the loss factor and tans of EPR were increased and loss factor and tan$\delta$ at peak temperature were decreased. Activation energies were calculated using loss factor and thermal decomposition for ${\gamma}$-ray irradiated EPR as well. The trends of both calculated activation energies showed the same tendencies as radiation dose was increased.

• 방사선산업학회지
• /
• 제5권3호
• /
• pp.237-242
• /
• 2011

In this research, the radiation resistance of ethylene propylene rubber (EPR) and chlorosulfonated polyethylene (CSPE) which can be used as a insulating materials of for electrical cable in the nuclear power plant were investigated. EPR and CSPE were irradiated by ${\gamma}$-ray at various doses ranging from 50 to 500 kGy at room temperature in air. The irradiated EPR and CSPE was investigated in terms of activation energy, mechanical properties, and oxidation stability. The experimental results revealed that CSPE exhibited the higher radiation resistance in comparison to that of EPR.

• Macromolecular Research
• /
• 제15권4호
• /
• pp.343-347
• /
• 2007

Novel composite membranes, which delivered high separation performance for propylene/propane mixtures, were developed by coating inert poly(ethylene-co-propylene) rubber (EPR) onto a porous polyester substrate, followed by the physical distribution of $AgBF_4$. Scanning electron microscopy-wavelength dispersive spectrometer (SEM-WDS) revealed that silver salts were uniformly distributed in the EPR layer. The physical dispersion of the silver salts in the inert polymer matrix, without specific interaction, was characterized by FT-IR and FT-Raman spectroscopy. The high separation performance was presumed to stem from the in-situ dissolution of crystalline silver ionic aggregates into free silver ions, which acted as an active propylene carrier within a propylene environment, leading to facilitated propylene transport through the membranes. The membranes were functional at all silver loading levels, exhibiting an unusually low threshold carrier concentration (less than 0.06 of silver weight fraction). The separation properties of these membranes, i.e. the mixed gas selectivity of propylene/propane ${\sim}55$ and mixed gas permeance ${\sim}7$ GPU, were stable for several days.

• 한국전기전자재료학회논문지
• /
• 제21권7호
• /
• pp.679-685
• /
• 2008

This paper describes the degraded properties of between the charge and discharge current for ${\gamma}$-ray irradiated in electric power cable rubbers using in nuclear power generating station. The charge and discharge current of degradation in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0.033 Mrad/h, have been measured in order to investigate the influence of the atmosphere(in amount of reinforcing agent, moisture absorption and heat treatment) on electrical properties. When ${\gamma}$-ray were irradiated on the EPR with more reinforcing agent from 4 to 40 Phr, charge and discharge currents was increase due to the amount of reinforcing agent. It was verified that the discharging and charging currents irradiated by ${\gamma}$-ray were higher than those that was not irradiated. The amount of the degraded current was more after moisture absorption than before moisture absorption. The charge and discharge current after heat treatment was similar to that of before heat treatment and it was decreased with the time elapsed. As these properties related with ${\gamma}$-ray irradiation dose, it is suggested that these properties can be utilized as a index of irradiation degradation.

• Elastomers and Composites
• /
• 제37권2호
• /
• pp.79-85
• /
• 2002

2몰% 에틸가지를 포함하는 에틸 가지화 폴리에틸렌[PE(2)]과 에틸렌-프로필렌 몰비가 50:50 으로 같지만 입체규칙성이 다른 랜덤-에틸렌-프로필렌 고무(r-EPR), 교호-에틸렌-프로필렌고무(alt-EPR) 및 이소탁틱-교호-에틸렌-프로필렌 고무(iso-alt-EPR)를 에틸렌-프로필렌 고무의 입체규칙성의 차이에 대한 혼화성과 물성의 차이를 조사하기 위하여 혼합하였다. 혼합된 블렌드의 결정화도는 고무상 EPR 성분의 증가에 따라 감소되었으며, EPR의 입체규칙성이 작을수록, 혼합조성의 증가할수록 감소하였다. 열역학적 interaction parameter(x) 값은 3가지 블렌드 모두 거의 영에 가까운 값을 나타내어 본 블렌드계는 PE(2)의 녹는점 가까이 또는 그 이상에서 상호간 섞일 것으로 판단되었다. 녹는점($T_m$)과 결정화온도($T_c$)의 측정에서부터 세가지 블렌드는 혼합조성과 입체규칙성에 관계없이 직선관계를 보여주어 이 블렌드계의 PE(2)의 용융거동은 주로 희석효과(diluent effect)에 기인함을 알 수 있었다. Small angle light scattering(SALS) 방법에 의한 PE(2)의 spherulite의 크기는 세가지 블렌드계가 EPR의 혼합비 증가에 따라 증가하였으며, 같은 혼합비에서는 r-EPR>alt-EPR>iso-alt-EPR> 순서로 증가하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.132-135
• /
• 2000

This paper present the results of measured Thermally Stimulated Current of EPR(Ethylene Propylene Rubber) sheet material with variation of bias temperature range of -35~80[$^{\circ}C$], the quality of the material of electrode, condition. The origins of these peaks are that, low temperature peak seems to result from dipole, and high temperature peak from the orientation electronic trap.

• 대한안전경영과학회지
• /
• 제2권2호
• /
• pp.187-200
• /
• 2000

The charge and discharge current in EPR(Ethylene Propylene Rubber), which were irradiated with the radiant capacity of 0~600 ［kgy/h］, have been measured in order to investigate the influence of the atmosphere (oxygen, air and vacuum) on electrical properties. It has been shown that the charge and discharge current increase as the amount of radiant capacity increases in air and vacuum atmosphere. This electrical property degradation can be speculated due to that the C＝O radicals or impurities, which comes from during shaping process, may act as dipoles. On the other hand, the charge and discharge current are shown to be higher in the amount of 1［kgy/h］ than these in 10［kgy/h］ in air atmosphere, because the charge and discharge current can be increased as the exposure time is extended with slower rate. Under the same amount of irradiation, the charge and discharge current in oxygen atmosphere are shown to be higher than those in vacuum. This is possibly due to that the main chain can be broken by oxidation when it is exposed to the $\gamma$ -rays.

• 유변학
• /
• 제5권2호
• /
• pp.144-148
• /
• 1993

Nylon-6의 내충격성을 개선하기 위한 개질제로써 에틸렌-프로필렌 고무(EPR)와 에 틸렌-아크릴 에스터-무수말레산 공중합체(EAM)를 첨가한 nylon-6/EPR/EAM 블렌드 시스 템의 유변학적 특성을 24$0^{\circ}C$에서 조사하였다. 개질제중 EAM의 점도는 조성물 가운데 가장 낮음에도 불구하고 첨가량을 증가함에 따라 블렌드의 점도는 증가하였다. 또한 EPR(I)의 점 도가 EPR(II)의 점도보다 낮지만 EAM 함량이 증가함에 따라 nylon-6/EPR(I)/EAM의 점도 는 nylon-6/EPR(II)/EAM의 점도보다 높아지는 현상이 관찰되었다. 이러한 특성을 분산상의 morphology 변화와 전단력하에서 변형이 어려워지기 때문인 것으로 해석하였다.