• 한국추진공학회지
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• 제16권2호
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• pp.73-79
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• 2012

본 연구에서는 높은 강도의 가스흐름으로부터 연소실 내부를 보호하기 위하여 carbon fabric을 삽입한 EPDM계 내열재를 개발하였다. 연소관 내열재의 삭마 특성을 시험하기 위하여 6-inch 모사모타에 extension tube를 연결하였고, 모타와 extension tube 사이에 구멍이 있는 FRP를 삽입하여 추진제 연소 시 높은 강도의 가스흐름을 유도하였다. 결과적으로 연소시험후 carbon fabric/EPDM 연소관 내열재의 삭마량은 다른 연소관 내열재들에 비해 감소하는 것으로 확인되었다.

• Elastomers and Composites
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• 제52권3호
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• pp.194-200
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• 2017

After the grafting of methacrylic acid (MA) to ethylene propylene diene monomer (EPDM), a new peak at $1704cm^{-1}$ corresponding to the carboxylic acid group was observed in the infrared (IR) spectrum. This characteristic MA molecule peak grew larger as the MA contents were increased. After casting films were prepared from pure EPDM and MA-grafted EPDM, differential scanning calorimeter (DSC) measurements were made the pure EPDM exhibited a melting point of approximately $45^{\circ}C$ while that of the MA-grafted EPDM was $135{\sim}140^{\circ}C$. As the graft ratio of MA increased, the absorbed heat capacity increased at temperatures near $135{\sim}140^{\circ}C$, indicating that an increased amount of MA reacted. Furthermore, owing to the addition of crystalline MA, it is expected that strength of the elastomer will improve as the graft ratio increases, as a result of the increased number of hard segments.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권8호
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• pp.445-450
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• 2000

Many successful developments and microscopic studies have been made on the high quality insulating materials. However, a little attention have given to the macroscopic interface in HV(High Voltage) insulating systems. In this study, AC interfacial breakdown strength and V-t characteristic of the interface between Epoxy/EPDM(ethylene propylene diene terpolymer) are investigated. Electrode system is designed to reduce the charges from electrodes and to have the tangential potentials along the interface between Epoxy/EPDM by FEM(finite elements method). The AC breakdown strength is observed when HV is given to the interface. It is shown that AC interfacial breakdown strength is improved by increasing interfacial pressure and oiling. In particular, it was saturated at certain interfacial pressure level. V-t characteristic is able to extend to the life time of the interface between Epoxy/EPDM. Oiling also plays a good roll in prolongation of the life time.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권10호
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• pp.479-488
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• 2001

The effects of accelerated Ultraviolet (UV) radiation on High temperature vulcanized (HTV), Room temperature vulcanized (RTV) silicone rubber and two types of ethylene propylene diene terpolymer (EPDM) used for composite insulator were inverstigated by hydrophobicity class (HC), surface voltage decay after corona charging, SEM-EDS, FTIR and XPS. The contact angle in two kinds of silicone rubber was scarcely change, but EPDM occurred to the loss of hydrophobicity followed by surface cracking and chalking. The surface voltage decay on UV-treated silicone rubber and EPDM showed a different decay trend with UV treatment. EDS and XPS analysis indicated that the oxygen content increased with UV treatment time in all samples. For silicone rubber, the oxidized groups of inorganic silica-like structure increased with UV treatment time. The oxidized carbon of C=0, O=C-O in EPDM increased. These oxidized surface for each material had different electrostatic characteristics, so deposited charges were expected to have different impacts on their surface hydrophobicity. The degradation mechanism based on our results was discussed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권10호
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• pp.494-499
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• 2001

The effects of accelerated Ultraviolet (UV) radiation on High temperature vulcanized (HTV), Room temperature vulcanized (RTV) silicone rubber and two types of ethylene propylene diene terpolymer (EPDM) used for composite insulator were investigated by hydrophobicity class (HC), surface voltage decay after corona charging, SEM-ES, FTIR and XPS. The contact angle in two kinds of silicone rubber was scarcely change, but EPDM occurred to the loss of hydrophobicity followed by surface cracking and chalking. The surface voltage decay on UV-treated silicone rubber and EPDM showed a different decay trend with UV treatment. EDS and XPS analysis indicated that the oxygen content increased with UV treatment time in all samples. For silicone rubber, the oxidized groups of inorganic silica-like structure increased with UV treatment time. The oxidized carbon of C=O, O=C-O in EPDM increased. These oxidized surface for each material had different electrostatic characteristics, so deposited charges were expected to have different impacts on their surface hydrophobicity. The degradation mechanism based on our results was discussed.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2011년도 제37회 추계학술대회논문집
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• pp.85-91
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• 2011

본 연구에서는 높은 강도의 가스흐름으로부터 연소실 내부를 보호하기 위하여 carbon fabric을 삽입한 EPDM계 내열재를 개발하였다. 연소관 내열재의 삭마 특성을 시험하기 위하여 6-inch 모사모타에 extension tube를 연결하였고, 모타와 extension tube 사이에 구멍이 있는 FRP를 삽입하여 추진제 연소시 높은 강도의 가스흐름을 유도하였다. 결과적으로 연소시험후 carbon fabric/EPDM 연소관 내열재의 삭마량은 다른 연소관 내열재들에 비해 감소하는 것으로 확인되었다.

• Elastomers and Composites
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• 제24권2호
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• pp.110-121
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• 1989

The radical initiated graft copolymerization of acrylonitrile(AN) and 4-chlorostyrene(4-Clst) onto ethylene-propylene-diene terpolymer(EPDM) rubber was investigated under various conditions. Graft copolymer(AU-EPDM-4-Clst) was isolated b: selective solvent extraction and identified by using IR spectroscopy. The percent grafting is determined as a function of solvent, reaction time, and monomer mole ratio. Percent grafting decreased in the order of tetrahydrofuran(THF)>THF/ethyl acetate(EA)(1 : 1)>cyclohexane/EA(1 : 1)>n-hexane/EA(1 : 1). Grafting increased continuously with increasing the reaction time up to 40 hr, beyond which the grafting levelled off. It was observed that percent grafting increased as increasing [4-Clst]/[AN] mole ratio, but decreased when [4-Clst]/[AN] mole ratio was higher than 1.60. The light resistance of graft copolymer(AN-EPDM-4-Clst) was better than that of ABS.

• Elastomers and Composites
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• 제34권5호
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• pp.407-413
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• 1999

비세라믹 복합절연소재는 기계적 물성, 환경문제, 대량생산과 용이한 설계등의 우수한 특성으로 인해 전력산업분야에서 관심의 대상이 되어왔다. 또한 세라믹 절연체에 비하여 가볍고, 더욱 강인한 물성을 가진다는 장점이 있다. 본 연구에서는 뛰어난 전기 절연 특성과 우수한 내열, 내산화, 내오존성과 내후성을 가진 ethylene propylene diene monomer(EPDM)를 절연소재로 사용하였다. 특히, EPDM은 다른 고무 복합체에 비해 우수한 소수성을 가지기 때문에 장기간 사용이 가능하다는 점에서 본 연구에서는 EPDM 복합체의 유변학적 물성, 전기적물성, 그리고 접촉각의 측정을 통한 소수성 및 회복력에 관한 연구를 하였다. 또한 SEM을 사용하여 표면 형태학적 연구를 수행하였다.

• Elastomers and Composites
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• 제51권3호
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• pp.175-180
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• 2016

Influence of amino acidic chemical on properties of maleic anhydride-grafted ethylene-propylene-diene terpolymer/zinc oxide (EPDM-g-MAH/ZnO) composites was investigated. 4-Aminosalicylic acid (ASA), 4-amino-2-methoxybenzoic acid (AMBA), 12-aminolauric acid (ALA), and glutamine (Gln) were employed as the amino acidic chemicals. Though small quantity (0.5 phr) of the amino acidic chemical was added to the EPDM-g-MAH/ZnO composite, the properties were notably changed. By adding the amino acidic chemical, the percent crystallinity and apparent crosslink density were reduced. Order of the percent crystallinity was related to that of the $pK_a$ values of amino acidic chemicals. By adding the amino acidic chemical, the basic tensile properties were on the whole improved. The experimental results were explained by the $pK_a$ values of amino acidic chemicals, change of zinc ionomer formation, and interactions between the additive and EPDM-g-MAH chain.

• 한국환경과학회지
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• 제19권3호
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• pp.365-370
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• 2010

In this study, we carried out the evaluation of EPDM(Ethylene Propylene Diene Monomer) reclaimed rubber mixing with natural rubber at various mixing ratio to reuse as rubber filler. The scorch time and moony viscosity was analyzed to evaluate the effect of cure behavior. And also, we analyzed the tensile strength, the elongation at break and cure time to evaluate the variation of cure behavior. As the results, the scorch time and optimal cure time was decreased according to the increasing of EPDM reclaimed rubber. However, the moony viscosity was increased at each mixing ratio. In case of the added EPDM reclaimed rubber was 20 phr(parts by weight per 100 parts by weight of rubber), the hardness and specific gravity was increased a little. The hardness and specific gravity was increased in rapidly under 40 phr of the added EPEM reclaimed rubber. The tensile strength and elongation at break of the compound of natural and EPDM reclaimed rubber was rapidly decreased compared with its natural rubber when the ratio of adding EPDM reclaimed rubber was over 40 phr.