• Composites Research
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• 제30권3호
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• pp.215-222
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• 2017

에폭시 수지의 열적 특성과 접합 특성에 대해 다중벽 탄소 나노 튜브 (MWCNT)의 효과가 이중 중첩 전단시험에 의해 연구되었다. Epoxy/MWCNT 복합 수지는 에폭시 수지(araldite 2011)에 다양한 질량 분율로 MWCNT를 분산하여 제조되었다. MWCNT의 효과를 확인하기 위해 접합강도 시험이 열특성 변형 만능재료시험기에 의해 진행되었고 충격강도 시험이 ASTM D256에 따라 진행되었다. 금속 판재와 탄소섬유강화복합재료가 실험 재료로써 사용되었으며, 열적 안정성 분석은 열 중량 분석기와 시차 주사 열량기에 의해 진행되었다. 또한 접합강도 시험 후 시편의 형태학적 특성은 주사전자현미경에 의해 관찰되었고 파괴거동을 알아보기 위하여 광학현미경을 사용하였다. 에폭시 수지와 비교하였을 때 epoxy/MWCNT 복합 수지가 물리적 특성이 향상되는 것을 나타내었다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.479-482
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• 1999

Cured epoxy resins are extensively used for the electrical insulation in high-voltage equipments. The bisphenol A-based epoxy resins lured with azine show, especially, good thermal properties and mechanical resistances. For the technical and economic reasons, varing amount of inorganic fillers are added to endow the required special properties. In the large generators and motors of power plants, epoxy insulation is disclosed to the harsh conditions like the superheated steam and abrupt temperature variation. Hygrothermal aging at elevated temperatures tends to induce degradation in epoxy resins. To predict the effect of this degradation in DGEBA/MDA/SN/zeolite system, we proceeded the forced moisture absorption experiment using the autoclave. The thermal properties of the untreated and treated specimens were analyzed by DSC and TGA under the nitrogen flowing condition. The moisture absorption results showed a weight increase during hygrothermal aging at 1207. At the initial aging period, the system leaded to more or less postcuring but more prolonged environmental aging leaded the discoloration of specimen and lowering the T$_{g}$./.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2005년도 추계 학술논문 발표대회
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• pp.183-186
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• 2005

This study investigates material properties of epoxy resins and reinforced materials for adhesion repairing-reinforced of RC construction. According to the test. elasticity modulus of mortar indicated 16-26(GPa) and that of concrete was 18-27(GPa). It became decreased as mixture proportion, W/C and fluidity of both mortar and concrete increased In addition the elasticity modulus of epoxy resins exhibited around 45.3-220(GPa), while that of steel plate and Carbon Bar indicated 338(GPa) and 34.1 (GPa), respectively. It is obvious that individual materials had big different value of elasticity modulus. Meanwhile, thermal expansion coefficients of mortar was 10-13 ${\mu}\varepsilon$ /$^{\circ}C$ and that of concrete was 9-11 $\mu \varepsilon$ /$^{\circ}C$ The increase of mixture Voportion and W/C resulted in lower value of thermal expansion coefficients and the increase of flow and slump exhibited slightly higher value. The epoxy resin indicated 41-54 ${\mu}\varepsilon$ /$^{\circ}C$ which is 4-5 times larger value than concrete and steel plate and Carbon Bar was 11.93 ${\mu}\varepsilon$ /$^{\circ}C$ and -1.68 ${\mu}\varepsilon$ /$^{\circ}C$ respectively. Hence, the adhesion strength of the epoxy resins should be considered before it is used in field condition, due to different thermal expansion coefficient of each material.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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• pp.164-167
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• 2004

The purpose of this study is to investigate the properties of composite systems using polymer cement and epoxy resins for waterproofing and anti-corrosion to concrete structures such as water supply facilities and sewage-works. In this study these engineering properties of composite systems using polymer-modified mortar and epoxy resins were examined and could be confirmed to satisfy the guidelines of KS. Especially, it was turn out that the adhesion properties was excellent and high crack-resistance up to 1.49mm will be perform.

• 한국산업융합학회 논문집
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• 제25권3호
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• pp.461-466
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• 2022

Epoxy resins are widely used in various industrial fields. However, they suffer from brittleness, an issue that must be addressed for further applications. To solve this problem, additional fillers are needed to improve the mechanical and thermal properties of the resins; zirconia is one such filler. However, it has been reported that aggregation may occur in the epoxy composites as the amount of zirconia increases, preventing enhancement of the mechanical strength of the epoxy composites. Herein, to reduce the aggregation, zirconia was well dispersed on halloysite nanotubes (HNTs), which have high thermal and mechanical strength, by a conventional wet impregnation method using zirconyl chloride octahydrate as a precursor. The mechanical and thermal strengths of the epoxy composites with The zirconia impregnated HNTs (Zr/HNT) were investigated. Zr/HNT were characterized by Scanning electron microscope (SEM), transmittance electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy. The thermal strength of the epoxy composites was studied by thermomechanical analysis (TMA) and the mechanical strength of the epoxy composites (flexural strength) was studied by using a universal testing machine (UTM). The mechanical and thermal strengths of the epoxy complex with Zr/HNT were improved compared to those of the epoxy complex with HNT, and also increased as the content of Zr/HNT increased.

• 한국인쇄학회지
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• 제11권1호
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• pp.45-55
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• 1993

• Bulletin of the Korean Chemical Society
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• 제27권10호
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• pp.1542-1548
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• 2006

Maleimide modified epoxy compounds were prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with diglycidylether of bisphenol-A. Triphenylphosphine was used as catalyst and methylethylketone as solvent. The resulting compound possessed both the oxirane ring and maleimide group. The curing reaction of the maleimide epoxy compound with amine curing agents such as 1-(2-aminoethyl) piperazine (AEP) and 5-amino-1,3,3-trimethylcyclohexane methylamine isophorone diamine, IPDA) were studied. Incorporation of maleimide groups in the epoxy resin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples were found to have good thermal stability, chemical resistance (acid/alkali/solvent) and water absorption resistance.

• Carbon letters
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• 제10권4호
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• pp.314-319
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• 2009

The surface treatment effects of reinforcement filler were investigated based on the dynamic mechanical properties of mutiwalled carbon nanotubes (MWCNTs)/epoxy composites. The as-received MWCNTs(R-MWCNTs) were chemically modified by direct oxyfluorination method to improve the dispersibility and adhesiveness with epoxy resins in composite system. In order to investigate the induced functional groups on MWCNTs during oxyfluorination, X-ray photoelectron spectroscopy was used. The thermo-mechanical property of MWCNTs/epoxy composite was also measured based on effects of oxyfluorination treatment of MWCNTs. The storage modulus of MWCNTs/epoxy composite was enhanced about 1.27 times through oxyfluorination of MWCNTs fillers at $25^{\circ}C$. The storage modulus of oxyfluorinated MWCNTs (OF73-MWCNTs) reinforced epoxy composite was much higher than that of R-MWCNTs/epoxy composite. It revealed that oxygen content led to the efficient carbon-fluorine covalent bonding during oxyfluorination. These functional groups on surface modified MWCNTs induced by oxyfluorination strikingly made an important role for the reinforced epoxy composite.

• 폴리머
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• 제27권3호
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• pp.183-188
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• 2003

유전체 분광계를 사용하여 불소함유 에폭시 수지, 벤조트리플루오라이드의 다이글리시딜 에테르(FER)/다이아미노다이페닐메탄 (DDM)과 비스페놀 A의 다이글리시딜 에테르 (DGEBA)DDM 시스템의 유전상수를 측정하였으며, DMA와 TGA에 의한 열분석을 통하여 유리 전이 온도 및 열분해 개시온도, 최대 무게 감량시 온도, 그리고 분해 활성화 에너지 등 열안정성 인자를 고찰하였다. 경화된 시편의 기계적 물성은 파괴 인성, 굴곡강도 및 충격강도 실험을 통하여 알아보았으며, 주사전자 현미경을 사용하여 시편의 파단 특성을 조사하였다. 실험 결과, DGEBA/DDM 시스템에 비해 FER/DDM 시스템은 낮은 유전 상수를 나타내었으며, 경화된 시편의 기계적 물성은 높은 값을 나타내었다. 이는 trifluoromethyl (CF$_3$) 기의 도입으로 인하여 전기적 특성과 기계적 물성이 증가한 것으로 사료된다.

• Environmental Analysis Health and Toxicology
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• 제19권3호
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• pp.271-278
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• 2004

Epoxy resins are mostly used as a molding material for drinking water tank. Bisphenol A is used at a constituent material for epoxy resins and is widely suspected to act as an endocrine disrupter. In this study, we investigated embryo hatching in zebrafish reared in water undergone leaching process of expoxy resin, and found a decreased survival rate. Bisphenol A eluted from epoxy resin in drinking water tank was completely degraded by TiO$_2$ photocatalysis. We detected 7.8 ng/ml of bisphenol A in epoxy resin tank, and observed that the concentration was undetectable after 48h photocatalysis over TiO$_2$. There was no toxicity in hatching rates in zebrafish and morphogenesis after photocatalysis. The effect of TiO$_2$ photocatalytic reactions on the catalase activities in the f]y stage of zebrafish was also examined. At 1 week post hatching, cataiase activities were higher both in the group of epoxy resin with 48 h TiO$_2$ photocatalysis and in the TiO$_2$ photocatalysis for 48 hours were higher than control group. However catalase activities of the treatment group of epoxy resin by TiO$_2$ photocatalysis for 48 hours were similar to control in 5 weeks post hatching fries. In conclusion, the toxicity of TiO$_2$ photocatalysis was not observed in this zebrafish.