• Polymer Science and Technology
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• v.10 no.3
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• pp.325-334
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• 1999

• Elastomers and Composites
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• v.33 no.4
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• pp.255-266
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• 1998

One-step continuous reactive blend with EPDM is investigated using a modular intermeshing corotating twin screw extruder This was performed via anionic polymerization mechanism. Mechanical properties were characterized and compared with mechanical blends.

• Elastomers and Composites
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• v.14 no.3
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• pp.161-168
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• 1979

이 논문(論文)의 목적(目的)은 열적안정성(熱的安定性) 및 내노화성면(耐老化性面)에 있어서 디엔제3성분단위체(第三成分單位體)(diene termonomer)의 각각(各各)의 종류(種類)가 EPDM의 중합체(重合體)의 성질(性質)에 미치는 효과(效果)를 구명(究明)하는데 있다. 제3성분단위체(第三成分單位體) 5종(種)으로 각각(各各) 다음과 같다. 즉, ethylidene norbonene(ENB), butadiene(BD), dicyclopentadiene(DCPD), methyltetrahydroindene (MTHI) 및 1,4-hexadiene(HD)이다. 이들을 써서 만든 각각(各各)의 EPDM은 동(同)몰의 불포화도(不飽和度)로 만들어졌다. 또한 가황계(加黃系)는 동일(同一)한 황/촉진제계(黃/促進劑系)를 사용(使用)하였다. ENB-EPDM이 순(純)고무배합체(配合體) 및 충전제함유배합체(充塡劑含有配合體)의 가황(加黃)에 있어서 모두 함께 가장 빠른 가황속도(加黃速度)를 보였다. HD-EPDM은 순(純)고무배합체(配合體)에서 가황속도(加黃速度)가 가장느렸으나 충전제함유배합물(充塡劑含有配合物)에서는 DCPD-EPDM보다는 발랐다. BD-EPDM을 제외(除外)한 이들 중합체(重合禮)는 거의 같은 초기가교밀도(初期架橋密度)를 갖는다. 가교밀도(架橋密度) 및 가교형(架橋型)을 분석(分析)하여 보면 BD-EPDM 쇄(鎖)에서 부타디엔 단위(單位)는 블럭을 이루고 있다. 또한 HD-EPDM은 순(純)고무가황체(加黃體) 및 충전제배합가황체(充塡劑配合加黃體)에 있어서 원가교결합(原架橋結合)의 50%가 monosulfide의 구조(構造)를 가지고있다. 이외(外)의 4종(四種)의 EPDM 폴리머는 보다 낮은 monosulfide구조를 가진다. $177^{\circ}C(350^{\circ}F)$의 노화온도(老化溫度)에서 ENB 및 HD폴리머는 약(約) 65% monosulfide 가교(架橋) 및 거의 동일(同一)한 파괴에너지값$(E_b)$을 가진다. 그러나 1,4HD의 원가교(原架橋)의 monosulfide 구조함량(含量)이 보다 높다고 해서 그의 내노화성(耐老化性)이 다른 폴리머보다 더 좋다고는 생각되지 않는다. DCPD는 $177^{\circ}C(350^{\circ}F)$의 노화온도(老化溫度)에서 똑같은 monosulfide가교(架橋)를 가지나 노화온도(老化溫度)가 $259^{\circ}C(500^{\circ}F)$로 높아짐에 따라 monosulfide 함량(含量)도 증가(增加)한다. $550^{\circ}F(287.7^{\circ}C)$의 노화온도(老化溫度)에서는 EPDM폴리머의 모든 가교(架橋)가 monosulfide구조가 되나 전가교밀도(全架橋密度) 및 $E_b$ (신장률(伸長率), 절단시(切斷時)의)는 대단(大端)히 낮은 것으로 나타나는데 이것은 산화(酸化)에 의한 노화(劣化)에 기인(基因)되는 것으로 보인다. 질소기류(窒素氣流)속에서의 TGA의 분석결과(分析結果)를 보면 EPDM 가황체(加黃體)는 $800\sim935^{\circ}F(427\sim502^{\circ}C)$의 온도범위(溫度範圍)에서 분해(分解)되며 공기중(空氣中)에서는 $750\sim935^{\circ}F$ 범위(範圍)에서 분해(分解)한다.

• Polymer(Korea)
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• v.32 no.3
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• pp.270-275
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• 2008

Crack growth characteristics of elastomeric materials are an important factor determining the strength and durability. In this study, the fatigue crack growth characteristic of filled EPDM compounds with different reinforcing fillers, such as silica and carbon black, was investigated using a newly designed tester. Frequency and test temperature had significant effects on the fatigue crack growth. The crack growth rate decreased with increasing frequency and the rate increased with increasing temperature. A power law relationship between the tearing energy and crack growth was observed for filled EPDM compounds. The crack growth rate reduced with increasing filler contents. Silica filled EPDM showed a better fatigue resistance than carbon black filled EPDM. The crack growth rate of silica filled EPDM decreased up to 30 phr and increased again at 50 phr. The formation of microductile type pits was observed on the fatigue-failure surface of unfilled EPDM, and relatively coarse surface with randomly distributed tear lines was observed on the failure surface of silica filled EPDM.

• Elastomers and Composites
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• v.34 no.5
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• pp.407-413
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• 1999

Non-ceramic composite insulator has been interested in the power industry because of its good characteristics in mechanical properties, mass product and design availability. Also it is lighter, and less unexplosive, compared to a ceramic insulator. Especially EPDM rubber composite insulator can be used for long-term in contaminated environments because of its hydrophobicity. This paper showed the rheological properties, the electrical properties, and contact angles to check the hydrophobicity and the recoverability of the EPDM compounds. Also, we investigated surface morphology of the compound by SEM.

• Elastomers and Composites
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• v.42 no.2
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• pp.112-118
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• 2007

An HRP immobilized carbon paste electrode, which was bound by EPDM, was newly fabricated and its electrochemical properties were investigated for the purpose of validating the new possibility for the practical use of biosensor. In the experimental range of substrate concentration, Lineweaver-Burk plot of the signal showed a good linearity. This means that HRP was embedded effectively to preserve its identity in the bulk of composite electrode materials and EPDM is a recommendatory binder. When the electrode was run at low operating potential($0.0\sim-1.0$ V vs. Ag/AgCl), it showed a high sensitivity and a good reproducibility. Especially the mechanical stability of the dried rubber was a remarkable breakthrough to get over a difficulty in putting the carbon-paste electrode bound with silicon oil to real use.

• Elastomers and Composites
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• v.35 no.2
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• pp.149-156
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• 2000

trans-octylene rubber(TOR) was melt-blended with an incompatible NBR/EPDM (70/30) blend. Mixing torque and temperature were reduced as TOR was added to the NBR/EPDM blend. Rheometer results indicated that TOR participated in vulcanization and became a part of network. A scanning electron micrograph demonstrated that EPDM was dispersed in NBR matrix in the blend and the addition of TOR led to a finer dispersion of EPDM particles. On the addition of TOR, the tensile strength, the tensile strain as well as the modulus of the blend vulcanizates increased. The ozone resistance of the blends determined in terms of critical stress-strain parameter was significantly enhanced in the blend as TOR was added. Improvements in the properties were believed to be associated with fine morphology and the increase in crosslink density due to the chain entanglement of the ternary blends.

• Polymer(Korea)
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• v.29 no.2
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• pp.166-171
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• 2005

EPDM (ethylene propylene diene monomer)/silicone rubber blends were prepared and the influence of a compatibilizer and thermal aging on the properties of the blends was investigated. The blends of which the compositions were varied in the range of 90/10 through $10/90\;wt\%$ were melt mixed by using a Brabender Plasticoder (internal mixer) and were vulcanized by a hot press. The morphology of the vulcanized EPDM/SR blends was examined by scanning electron microscopy (SEM). After the thermal Aging for 24, 48, 96 hrs at $100^{\circ}C$ in an air oven, hardness, tensile strength, elongation and contact angle of the blends were investigated. From the result of the morphology, it was confirmed that the domain size of the blends containing the compatibilizer was reduced. As the increase of the thermal aging time, hardness and tensile strength of the blends decreased but elongation and contact angle increased.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.5
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• pp.152-162
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• 2005

Coolant rubber hoses for automobile radiators can be degraded and thus failed due to the influence of contacting stresses of air and coolant liquid under the thermal and mechanical loadings. In this study, test analysis was carried out for evaluating the degradation and failure mechanisms of coolant hose materials. Two kinds of EPDM rubber materials applicable to the hoses were adopted: commonly-used ethylene-propylene diene monomer(EPDM) rubbers and EPDM rubbers with high resistance against electro-chemical degradation (ECD). An increase of surface hardness and a large reduction of failure strain were shown due to the formation of oxidation layer for the specimens which had been kept in a high temperature air chamber. Coolant ageing effects took place only by an amount of pure thermal degradation. The specimens degraded by ECD test showed a swelling behavior and a considerable increase in weight on account of the penetration of coolant liquid into the skin and interior of the rubber specimens. The ECD induced material softening as well as drastic reduction in strength and failure strain. However EPDM rubbers designed for high resistance against ECD revealed a large improvement in reduction of failure strain and weight. This study finally established a procedure for reliability analysis and evaluation of the degradation and failure mechanisms of EPDM rubbers used in coolant hoses for automobile radiators.

• Elastomers and Composites
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• v.7 no.2
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• pp.183-192
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• 1972

As a series of tile studies of EPDM-Polymer blends, tile experiment are concentrated to the investigation of the physical properties of tile EPDM-NR-SBR blends. The results are shown as follows: 1. In blending, tensile strength decreased with increase in EPDM contents, especially the ratio of EPDM/NR-SBR is 75/25. 2. Elongation and tear strength were much influenced by blending, especially the ratio of EPDM/NR-SBR is 50/50. 3. Ozone resistance is much improved after blending. It was effective more than tile ratio of EPDM/NR-SBR is 25/75. 4. Aging resistance is much improved after blending. It was effective more than the ratio of EPDM/NR-SBR is 50/50. 5. Hardness increased with increase in EPDM contents and on the other hand, abrasion resistance decreased.