• Title/Summary/Keyword: epoxy type resin

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Study on the Thin-walled carbon nanotubes (TWNTs)/Amine epoxy additive composite via supercritical fluid process (초임계 공정을 이용한 Thin-walled carbon nanotubes (TWNTs)/아민계 에폭시 첨가제의 복합체 제조)

  • Kim, Yong-Ryeol;Jeong, Hyeon-Taek
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.3
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    • pp.486-491
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    • 2014
  • We have been fabricated Thin-walled carbon nanotubes (TWNTs)/amine epoxy additives composite using Eco-friendly solvent system such as supercritical process and dry mixed process. TWNTs/amine epoxy additives composite has used as a curing agent for urethane based bisphenol A type epoxy resin. The thermo-mechanical property of the epoxy resin cured by TWNTs/amine epoxy additives composite is characterized by dynamic mechanical analysis(DMA) and dispersability of the nanotubes in the epoxy matrix is also confirmed by scanning electron microscope(SEM). As a results, the epoxy resin cured by TWNTs/amine epoxy additives composite with supercritical process shows enhanced dispersability of the TWNTs in the matrix and thermo-mechanical property when compare to dry mixed process.

Effect of Electric Field Frequency on the AC Electrical Treeing Phenomena in an Epoxy/Reactive Diluent/Layered Silicate Nanocomposite

  • Park, Jae-Jun
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.2
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    • pp.87-90
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    • 2014
  • The effects of electric field frequency on the ac electrical treeing phenomena in an epoxy/reactive diluent/layered silicate (1.5 wt%) were carried out, in needle-plate electrode arrangement. A layered silicate was exfoliated in an epoxy base resin, by using our ac electric field apparatus. To measure the treeing propagation rate, constant alternating current (AC) of 10 kV with three different electric field frequencies (60, 500 and 1,000 Hz) was applied to the specimen, in needle-plate electrode arrangement, at $30^{\circ}C$ of insulating oil bath. As the electric field frequency increased, the treeing propagation rate increased. At 500 Hz, the treeing propagation rate of the epoxy/PG/nanosilicate system was $0.41{\times}10^{-3}$ mm/min, which was 3.4 times slower than that of the epoxy/PG system. The electrical treeing morphology was dense bush type at 60 Hz; however, as the frequency increased, the bush type was changed to branch type, having few branches, with very slow propagation rate.

Analysis on Thermal Transfer Characteristics of 50 kVA Mold-Transformer (50[kVA] 몰드변압기 권선부의 열전달 특성 해석)

  • 이현진;정중일;허창수;조한구
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.3
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    • pp.47-54
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    • 2002
  • This paper presented the charcteristic of the thermal transfer in a 50[kVA] cast-resin dry type transformer. The conductivity of the primary winding composed were a Plenty of epoxy-resin ard a little of Cu was determined by that rating. Otherwise the conductivity of the secondary winding composed of a plenty of Cu and a little of epoxy-resin was determined by comparing the data of analysis using FEM method with those of temperature tests of the prototype cast-resin transformer. Based on the reults of the physical characteristics and the simulation by commercial using FEM method we established the prototype Model for this test. According to that Model, an analysis on variation of the temperature was discussed as a function of ambient temperature and velocities in the 50[kVA] cast-resin dry type transformer.

Corrosion-Inhibition and Durability of Polymer-Modified Mortars Using Bisphenol A and F Type Epoxy Resin with Calumite (비스페놀 A 및 F형 에폭시수지와 칼루마이트를 병용한 폴리머 시멘트 모르타르의 방청성 및 내구성)

  • Kim, Joo-Young;Kim, Wan-Ki
    • Journal of the Korea Concrete Institute
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    • v.26 no.4
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    • pp.517-524
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    • 2014
  • Nitrite-Type hydrocalumite (calumite) is a material that can adsorb chloride ions ($Cl^-$) that cause corrosion of reinforce bars and liberate the nitrite ions ($NO_2{^-}$) that inhibit corrosion in reinforced concrete. In this study, polymer-modified mortars using two types of epoxy resin with calumite are prepared with various polymer binder-ratios of 0, 5, 10, 15, 20% and calumite contents of 0, 5%. The specimens are tested for chloride ion penetration, carbonation, drying shrinkage and corrosion inhibition. As a result, the chloride ion penetration and carbonation depth of PMM using epoxy resin somewhat increases with increasing calumite contents, but those remarkably decreases depending on the polymer-binder ratios. The 28-d drying shrinkage shows a tendency to decrease with increasing polymer-binder ratio and calumite content. Unmodified mortars with calumite content of 5% did not satisfy quality requirement by KS. However, it was satisfied with KS requirement by the modification of epoxy resin in cement mortar. On the whole, the carbonation and chloride ion penetration depth of epoxy-modified mortars with calumite is considerably improved with an increase in the polymer-binder ratio regardless of the calumite content, and is remarkably improved over unmodified mortar. And, the replacement of the portland cement with the calumite has a marked effect in the corrosion-inhibiting property of the epoxy-modified mortars.

The Moisture Absorption Properties of Liquid Type Epoxy Molding Compound for Chip Scale Package According to the Change of Fillers (충전재 변화에 따른 Chip Scale Package(CSP)용 액상 에폭시 수지 성형물 (Epoxy Molding Compound)의 흡습특성)

  • Kim, Whan-Gun
    • Journal of the Korean Chemical Society
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    • v.54 no.5
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    • pp.594-602
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    • 2010
  • Since the requirement of the high density integration and thin package technique of semiconductor have been increasing, the main package type of semiconductor will be a chip scale package (CSP). The changes of diffusion coefficient and moisture content ratio of epoxy resin systems according to the change of liquid type epoxy resin and fillers for CSP applications were investigated. The epoxy resins used in this study are RE-304S, RE310S, and HP-4032D, and Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The micro-sized and nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these epoxy molding compound (EMC) according to the change of filler size. The temperature of glass transition (Tg) of these EMC was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these EMC according to the change of time were observed at $85^{\circ}C$ and 85% relative humidity condition using a thermo-hygrostat. The diffusion coefficients in these EMC were calculated in terms of modified Crank equation based on Ficks' law. An increase of diffusion coefficient and maximum moisture absorption ratio with Tg in these systems without filler can be observed, which are attributed to the increase of free volume with Tg. In the EMC with filler, the changes of Tg and maximum moisture absorption ratio with the filler content can be hardly observed, however, the diffusion coefficients of these systems with filler content show the outstanding changes according to the filler size. The diffusion via free volume is dominant in the EMC with micro-sized filler; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the EMC with nano-sized filler.

A Study on Long-time Electrical Treeing Deterioration Properties According to High Frequency Voltage of Epoxy Resin (에폭시수지의 고전압 전원주파수 변화에 따른 장시간 전기적 트리잉 열화 특성연구)

  • Park, Jae-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.11
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    • pp.1571-1577
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    • 2013
  • Electrical tree structure is one of the most important influencing factors for electrical treeing characteristics in polymers. In this paper, we focused on the structure characteristics of electrical treeing in epoxy resins (original) insulation under different high-frequency voltages (60, 500, 1000Hz). Effects of voltage frequency on the ac electrical treeing phenomena in an epoxy resins were carried out in needle-plate electrode arrangement. To measure the treeing initiation and propagation, and the breakdown rate, constant AC of 10 kV with three different voltage frequencies (60, 500 and 1,000 Hz) was applied to the specimen in needle-plate electrode specimen at $30^{\circ}C$ of insulating oil bath. At 60 Hz, the treeing initiation time was 360 min and the propagation rate was $6.85{\times}10^{-4}mm/min$, and the morphology was dense branch type. As the voltage frequency increased, the treeing initiation time decreased and the propagation rate increased. At 1,000 Hz, the treeing initiation time was 0 min and the propagation rate was $7.81{\times}10^{-2}mm/min$, and the morphology was dense bush type.

Effect of Carbon Fiber Filament and Graphite Fiber on the Mechanical Properties and Electrical Conductivity of Elastic Carbon Composite Bipolar Plate for PEMFC (PEMFC용 탄성 탄소 복합재료 분리판의 기계적 강도 및 전기전도도에 미치는 탄소섬유 필라멘트와 흑연 섬유의 영향)

  • Lee, Jaeyoung;Lee, Wookum;Rim, Hyungryul;Joung, Gyubum;Lee, Hongki
    • Transactions of the Korean hydrogen and new energy society
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    • v.25 no.2
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    • pp.131-138
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    • 2014
  • Highly conductive bipolar plate for polymer electrolyte membrane fuel cell (PEMFC) was prepared using phenol novolac-type epoxy/graphite powder (GP)/carbon fiber filament (CFF) composite, and a rubber-modified epoxy resin was introduced in order to give elasticity to the bipolar plate graphite fiber (GF) was incorporated in order to improve electrical conductivity. To find out the cure condition of the mixture of novolac-type and rubber-modified epoxies, differential scanning calorimetry (DSC) was carried out and their data were introduced to Kissinger equation. And tensile and flexural tests were carried out using universal testing machine (UTM) and the surface morphology of the fractured specimen and the interfacial bonding between epoxy matrix and CFF or GF were observed by a scanning electron microscopy (SEM).

Tensile Properties of Plain Weave Glass Fabric Reinforced Epoxy Resin Laminates at Low Temperatures (평직유리섬유 강화 에폭시 적층판의 저온 인장 특성)

  • Kim, Yon-Jig
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.32 no.9
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    • pp.788-795
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    • 2008
  • To understand the tensile behaviors of GFRP at low temperature, three types of specimen have been used in this study. Tensile properties and fracture mechanisms for three orthogonal orientations of plain weave glass fabric reinforced epoxy resin laminate were investigated at temperature range of about -30 to $15^{\circ}C$. The tensile properties of axial and edge type specimen decrease slightly with decreasing temperature to $-20^{\circ}C$. However, at $-30^{\circ}C$ the decreases in the tensile properties increased considerably. Below $-20^{\circ}C$, thickness type specimen showed a marked decreases in the tensile properties. It was obvious that the fracture manner of thickness type specimen was adhesive failure at above $-10^{\circ}C$ and a mixed adhesive and cohesive failure at below $-20^{\circ}C$.

Mechanical Properties Anisotropy of Plain Weave Glass Fabric Reinforced Epoxy Resin Laminates (평직유리섬유강화 에폭시 적층판의 기계적 특성 이방성)

  • Kim, Yon-Jig
    • Transactions of the Korean Society of Automotive Engineers
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    • v.17 no.3
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    • pp.15-21
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    • 2009
  • The anisotropic mechanical properties were measured for the three orthogonal orientations of plain weave glass fabric reinforced epoxy resin laminate. In tensile and flexural tests, axial and edge type specimens failed by pull-out of warp and fill yarns, respectively. In contrast, the thickness type specimens failed by adhesive failure process. Longitudinal cracking occurred in several of the edge type specimens during tensile test. That cracking caused pop-in in the stress-strain curve. Defects induced by improper coupon machining caused that cracking.

Effect of Ambient Temperature on the AC Electrical Treeing Phenomena in an Epoxy/Layered Silicate Nanocomposite

  • Park, Jae-Jun
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.4
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    • pp.221-224
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    • 2013
  • Effects of ambient temperature on the ac electrical treeing and breakdown behaviors in an epoxy/layered silicate (1 wt%) were carried out in needle-plate electrode geometry. A layered silicate was exfoliated in an epoxy base resin,, using our ac electric field apparatus. To measure the treeing initiation and propagation, and the breakdown rate, constant alternating current (ac) of 10 kV (60 Hz) was applied to the specimen in a needle-plate electrode arrangement, at $30^{\circ}C$, $90^{\circ}C$ or $130^{\circ}C$ of insulating oil bath. At $30^{\circ}C$, the treeing initiation time and the breakdown time in the epoxy/layered silicate (1 wt%) system were 1.4 times higher than those of the neat epoxy resin. At $90^{\circ}C$ (lower than Tg), electrical treeing was initiated in 55 min, and propagated until 1,390 min at the speed of $0.35{\times}10^{-3}mm/min$, which was 4.4 times higher than that at $30^{\circ}C$; however, there was almost no further treeing propagation after 1,390 min. At $130^{\circ}C$ (higher than Tg), electrical treeing was initiated in 44 min, and propagated until 2,000 min at the speed of $0.96{\times}10^{-3}mm/min$. Typical branch type electrical treeing was obtained from the neat epoxy and epoxy/layered silicate at $30^{\circ}C$, while bush type treeing was observed out from the needle tip at $90^{\circ}C$ and $130^{\circ}C$.