• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.293-296
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• 1998

Surface electrical conduction in insulator is most important factor to assess the insulation performances of outdoor insulating materials. In this paper, contamination performance of the widely used materials for outdoor insulator - porcelain, EPDM, Silicone rubber - were discussed by measuring properties of average leakage current and scintillation discharge pulses under artificial contamination conditions. The artificial contaminations used were deionized distilled water fog, 0.5wt% NaCl salt fog of light pollution and 2wt% NaCl salt fog of medium pollution. The average leakage current was appeared linearly with applied voltage at dry and clean surface condition. The magnitude of leakage current was almost same at different kinds of samples. In case of deionized distilled water fog, the characteristics of leakage current and applied voltage was most different to that in case of dry and clean condition. In case of salt fog pollution condition, The leakage current was increased above critical voltage. The scintillation discharges were also activated at the level. the leakage current and scintillation discharges were increased with increasing pollution degree. The resistance to pollution properties of silicone rubber appeared excellent among them.

• Elastomers and Composites
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• 제36권2호
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• pp.86-93
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• 2001

새로운 TPE(Thermoplastic Elastomer) 블렌드 재료로서 폐 EPDM(Ethylene Propylene Diene Monomer)분말의 사용에 따른 환경문제를 해결하고, TPE의 고부가 가치화를 위하여 PP (Polypropylene)와 폐 EPDM분말을 주원료로 하고, 동방향 이축압출기(Co-rotating Twin Screw Extruder)를 사용하여 동적가교를 이루어 TPE재료를 제조하였다. TPE 재료의 인장강도, 파단신율, 탄성율 등의 물성을 향상시킬 목적으로 스크류 조합별로 폐 EPDM/PP를 블렌드하여 기계적물성을 조사하였으며, 모폴로지를 조사하였다. 스크류 조합에서는 혼련판과 역 스크류 엘리먼트의 수가 증가할수록 블렌드물의 전단력과 체류시간이 증가하여 동적가교가 증가하였다.

• Computers and Concrete
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• 제27권3호
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• pp.185-197
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• 2021

Throughout the previous years, many efforts focused on incorporating non-biodegradable wastes as a partial replacement and sustainable alternative for natural aggregates in cement-based materials. Currently, rubberized concrete is considered one of the most important green concrete materials produced by replacing natural aggregates with rubber particles from old tires in a concrete mixture. The main benefits of this material, in addition to its importance in sustainability and waste management, comes from the ability of rubber to considerably damp vibrations, which, when used in reinforced concrete structures, can significantly enhance its energy dissipation and vibration behavior. Nowadays, the literature has many experimental findings that provide an interesting view of rubberized concrete's dynamic behavior. On the other hand, it still lacks research that collects, interprets, and numerically investigates these findings to provide some correlations and construct reliable prediction models for rubberized concrete's dynamic properties. Therefore, this study is intended to propose prediction approaches for the dynamic properties of rubberized concrete. As a part of the study, multiple linear regression and artificial neural networks will be used to create prediction models for dynamic modulus of elasticity, damping ratio, and natural frequency.

• 대한치과기공학회지
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• 제10권1호
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• pp.43-46
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• 1988

The purpose of this investigation was to determined the dimensional change of plaster to time with impression materials. This study was carried out through the literature & experiment, using 4sorts of the Impression Materials(Alginate, Impression Agar, Silicone Rubber, Polysulfide Rybber)and 5 treatments(1hr, 11/2 hrs, 2hur, 3hur, 6hur). The results of this experiment were as follows : 1. Main effect of Impression Meterials & tretments was statistically significant.(P<0.01). 2. The effect of 2-way interaction of Impression materials & Treatments was also statistically significant.(P<0.01) 3. Though this study was the difference of degree according to the materials. All Impression Materials were tended to be constained according to over the time.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제52권8호
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• pp.359-364
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• 2003

Ageing characteristics of RTV coating materials by corona discharge have been studied. The hydrophobicity recovery of RTV coating materials with 300${\mu}{\textrm}{m}$ thickness was identical with a bulk silicone materials. The RTV coating materials hydrophobicity has been almost lost when its were discharged during 40 seconds by corona discharge of 10㎸, and recovered after about 45 hours. The resistivity of RTV coating materials has not been recovered after 45 hours, though after 80 hours the initiation resistivity value has been recovered up to 95%. There was no critical change of compounds(such as Si and Al) on RTV surfaces by the corona discharge treatment until 100 seconds. In the test of arc erosion, it was seen that the coating sample with silicone rubber as a base material have more longer burn-out time than other samples with FRP or glass base.

• Elastomers and Composites
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• 제59권1호
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• pp.22-33
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• 2024

Passive radiative cooling is a promising technology for cooling objects without energy input. Passive radiative cooling works by radiating heat from the surface, which then passes through the atmosphere and into space. Achieving efficient passive radiative cooling is mainly accomplished by using materials with high emissivity in the atmospheric window (8-13 ㎛). Research has shown that polymers tend to exhibit high emissivity in this spectral range. In addition to elastomers, other materials with potential for passive radiative cooling include metal oxides, carbon-based materials, and polymers. The structure of a passive radiative cooling device can affect its cooling performance. For example, a device with a large surface area will have a greater amount of surface area exposed to the sky, which increases the amount of thermal radiation emitted. Passive radiative cooling has a wide range of potential applications, including building cooling, electronics cooling, healthcare, and transportation. Current research has focused on improving the efficiency of passive radiative cooling materials and devices. With further development, passive radiative cooling can significantly affect a wide range of sectors.

• 접착 및 계면
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• 제10권3호
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• pp.148-153
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• 2009

용제 및 수용성 접착제를 도포한 몇가지 고분자 소재에 평판형 플라즈마 반응기로 플라즈마 전처리 방식을 이용하여 소재표면의 접착력을 향상 시켰다. 분위기 기류를 질소로 하고 유량을 30~100 mL/min, 반응시간은 0~30 s로 하여 밀도를 변화시킨 PU 소재를 주 물질로 하여 EVA foam, Leather (Action), Rubber 소재에 대하여 각 조건별로 플라즈마 처리시켜 처리 전후의 각 소재별 접촉각과 접착박리강도 측정을 통한 각소재의 접착력 변화와, SEM분석을 이용한 처리 전후의 표면 변화를 측정하여 플라즈마 처리의 영향과 효과를 산출하였다. 대기압 평판형 플라즈마 반응기를 이용하여 최적 조건인 기체유량 100 ml/min, 전처리시간 10 s에서 PU foam, EVA form, Leather (Action) 및 Rubber 소재의 접착력 향상을 확인하였다.

• Composites Research
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• 제17권3호
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• pp.45-50
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• 2004

계면상 조건과 섬유 함유량 변화에 따른 단섬유 강화 CR의 동적특성에 대해 주파수, 진폭 그리고 온도를 함수로 실험적 고찰을 하였다. 진폭 변형률 증가에 따라 LF는 1.33% 이상에서 약간 증가하였고, DR은 크게 감소하였다. 주파수 증가에 따라 LF는 특히 50Hz 이후 크게 감소하였고, DR은 기지고무보다 낮은 값을 보였다. 온도 증가에 따라 LF는 $65^{\circ}$에서 최대 값을 나타내고 이후 크게 감소세를 보였다. DR은 온도가 증가에 따라 기지고무 보다 낮은 값을 보였다. 일반적으로 동일한 시험 조건에서 계면상이 우수할수록 LF와 DR이 낮은 값을 보였다. 따라서 단섬유 강화고무는 진동 수비가 $\sqrt{2}$ 이하보다는 $\sqrt{2}$ 이상에서 더 큰 진동절연 효과가 있다고 할 수 있다.

• Elastomers and Composites
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• 제47권3호
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• pp.254-258
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• 2012

자동차 엔진 개스킷용 아크릴 고무(ACM)의 재료 특성과 수명 예측에 관하여 연구하였다. 클로린 가교사이트를 포함하는 ACM (Chlorine Cure-Site ACM)과 카르복실기 가교사이트를 포함하는 ACM (Carboxyl Cure-Site ACM)을 이용하여 최적상태의 배합물을 제작하여 특성을 살펴보았다. 엔진용 개스킷의 주요한 특성인 열과, 엔진오일에서의 압축영구줄음율을 시험 평가한 결과 Carboxyl Cure-Site ACM 배합물이 상대적으로 더 우수한 것으로 나타났다. Carboxyl Cure-Site ACM 고무 재료에 대한 수명을 예측하기 위해 가속열노화시험을 수행하여 시간-온도 환산식인 아레니우스(Arrhenius) 관계식을 구하였다.

• 한국가스학회지
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• 제18권5호
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• pp.26-32
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• 2014

CCS(Carbon Capture and Storage)는 제철, 철강, 발전소 등에서 발생되는 $CO_2$를 포집 및 저장하는 기술로서, 지구 온난화의 주범인 $CO_2$를 감축시키는 효과적인 기술이다. CCS 포집 기술과 저장 기술은 집중적인 개발을 도모하고 있으며, 현재 실증단계에 있다. 그러나 상용화 단계에 이르기 위해서는 포집, 저장 기술을 비롯하여 수송기술까지도 구성 요소에 대한 안전성 확보가 필요하다. 특히, 수송기술은 CCS 특성상 파이프라인을 이용한 수송기술이 적합하지만, $CO_2$ 파이프라인 운용 사례가 부족하여, 파이프라인 또는 구성 요소(밸브 등)에 대한 적합한 재질을 선택해야 한다. 본 연구에서는 $CO_2$ 파이프라인에 사용 가능한 고무재질을 알아보고자 여러 분야에서 사용되는 고무 재질을 $CO_2$에 침지하여 압력 온도 변화에 따른 부피변화를 비교 분석 하였다.