• Title, Summary, Keyword: epoxy

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The Effects of a Chain Extending Agent and Crosslinking Agent on the Toughness of Castor Oil based Polyurethane-Epoxy IPNs (Castor Oil형 폴리우레탄-에폭시 IPNs에서 사슬연장제와 가교제의 영향에 의한 강인성)

  • Kim, Jong-Seok;Yang, Yeong-Seok
    • Applied Chemistry for Engineering
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    • v.10 no.5
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    • pp.639-643
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    • 1999
  • Interpenetrating polymer networks(IPNs) composed of castor oil(CO) polyurethane(PU) and epoxy resin were prepared by the simultaneous polymerization technique. Two types of PU were prepared using 1,4-butanediol(BD) and BD/trimethylolpropane(TMP) as a chain extending agent and crosslinking agent. The PU/epoxy based on BD as a chain extending agent showed more shift in the damping peak than PU/epoxy based on BD/TMP as the PU content was increased. BDPU/epoxy simultaneous interpenetrating polymer networks(SINs) had a better compatibility than BD/TMP-PU/epoxy SINs. For both systems, it was postulated that unique network formation of PU/epoxy SINs as a chain extending agent and crosslinking agent had occurred to a significant extent of phase mixing. The types of chain extender in the PU were found to be an important factor in determining the phase mixing of the IPNs. When the BD/TMP-PU reaction was faster than epoxy network, the extent of phase mixing was retarded by decreasing entanglement of networks. It was found that both PU/epoxy SINs provided enhanced flexural properties and fracture toughness, fracture surfaces of BDPU/epoxy and BD/TMP-PU/epoxy SINs showed the localized shear deformation and generation of stress whitening associated with the cavitation.

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Effects of Curing Agent on the Corrosion Protection of Diglycidyl Ether Bisphenol-A Based Epoxy Coating

  • Shon, MinYoung;Kwon, HyukSang
    • Corrosion Science and Technology
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    • v.7 no.6
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    • pp.344-349
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    • 2008
  • Epoxy coatings were prepared to give a different corrosion protection by reacting it with two different kinds of curing agent, and then effects of the curing agents on the structure, surface hydrophobic tendency, water transport behavior and hence corrosion protection of epoxy coatings were examined using hygrothermal cyclic test, and impedance analysis. In the results of EIS, the corrosion protection of epoxy coating cured by polyamide shows better than epoxy coating cured by polyamide epoxy adduct. It was well agreed with its water transport behavior and hydrophobic tendency.

Effect of Oxidation of Graphene Nanoplatelets on the Mechanical Properties and Bonding Performance of Epoxy Paints (그래핀 나노플레이트릿의 산화가 에폭시 도료의 역학적 특성 및 부착 성능에 미치는 영향)

  • Chum, Sung-Ho;Kim, Gyu-Yong;Lee, Sang-Kyu;Hwang, Eui-Chul;Son, Min-Jae;Nam, Jeong-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.31-32
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    • 2019
  • In this study, oxidized graphene nanoplatelet(GO) was prepared by oxidizing graphene nanoplatelet(GNP) with nitric acid in order to solve the problem of dispersion of GNP, one of nano materials. GNP/Epoxy and GO/Epoxy paint were prepared by mixing GNP, GO with 0.1, 0.3, 0.5 and 1.0 wt.% in epoxy paint and the mechanical properties were evaluated. As a result, GNP/Epoxy and GO/Epoxy paints showed better mechanical properties than Neat Epoxy which did not incorporate GNP, GO. Especially, when 0.3 wt.% of GO was incorporated into epoxy resin, it showed higher tensile strength than Neat Epoxy. It was confirmed that acid treatment of GNP was effective in improving the mechanical properties of epoxy paint. However, graphene material was found that it was not effective in improving the bond performance of the epoxy paint.

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Study on Properties of Waterborne Polyurethane-Epoxy Hybrid Resin for Leather Garment Coationgs (의상 피혁 가공용 수용성 폴리우레탄-에폭시 하이브리드 수지의 합성 및 물성에 관한 연구)

  • Lee, Joo-Youb;Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
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    • v.27 no.3
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    • pp.325-336
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    • 2010
  • In this study, we experimented that how to synthesis waterborne urethane-epoxy hybrid resin for leather garment coatings. First of all, We had analyzed datas by FT-IR, SEM and TGA for the machanical properties. By instruments analysis measurement we confirmed that synthesis of urethane and epoxy. In this experiment we knew that polyurethane and urethane-epoxy hybrid resin have 4~5 grades of solvent resistance. Tensile strength measured in the urethane-epoxy resin(epoxy 12%, 2.033$kg_f/mm^2$) had the most strong strength than polyurethane(1.833 $kg_f/mm^2$) emulsion samples. Also urethane-epoxy hybrid resin had better result than polyurethane in acid resistance and abrasion test. As hight proportion of epoxy in hybid resin, we obtained low elongation and low flexibility. In this result, the mechanical properties of waterborne polyurethane-epoxy hybrid resin showed that how effect in leather coating by ratio of epoxy emulsion.

Effect of structural voids on mesoscale mechanics of epoxy-based materials

  • Tam, Lik-ho;Lau, Denvid
    • Coupled systems mechanics
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    • v.5 no.4
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    • pp.355-369
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    • 2016
  • Changes in chemical structure have profound effects on the physical properties of epoxy-based materials, and eventually affect the durability of the entire system. Microscopic structural voids generally existing in the epoxy cross-linked networks have a detrimental influence on the epoxy mechanical properties, but the relation remains elusive, which is hindered by the complex structure of epoxy-based materials. In this paper, we investigate the effect of structural voids on the epoxy-based materials by using our developed mesoscale model equipped with the concept of multiscale modeling, and SU-8 photoresist is used as a representative of epoxy-based materials. Developed from the results of full atomistic simulations, the mesoscopic model is validated against experimental measurements, which is suitable to describe the elastic deformation of epoxy-based materials over several orders of magnitude in time- and length scales. After that, a certain quantity of the structure voids is incorporated in the mesoscale model. It is found that the existence of structural voids reduces the tensile stiffness of the mesoscale epoxy network, when compared with the case without any voids in the model. In addition, it is noticed that a certain number of the structural voids have an insignificant effect on the epoxy elastic properties, and the mesoscale model containing structural voids is close to those found in real systems.

Effect of Particle Size and Dispersion on Dielectric Properties in ZnO/Epoxy Resin Composites

  • Yang, Wenhu;Yi, Ran;Yang, Xu;Xu, Man;Hui, Sisi;Cao, Xiaolong
    • Transactions on Electrical and Electronic Materials
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    • v.13 no.3
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    • pp.116-120
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    • 2012
  • In this paper, ZnO-Epoxy nanocomposites (NEP) were prepared and epoxy composites that contain 5 wt% micro ZnO (MEP) and deliberately not well dispersed nano ZnO (NDNEP) were also prepared for purpose of comparison. The effects of the particle size and dispersion of ZnO on dielectric properties of epoxy resin were chiefly studied. Test results showed that: at a loading of 5 wt%, the three epoxy composites seem to have no significant difference on resistivity compared to epoxy resin; Dielectric constants of all the epoxy composites are also basically the same but they are bigger compared to that of the pure epoxy resin (unfilled); Dielectric dissipation factors ($tan{\delta}$) of NDNEP is greater than that of NEP and MEP. NEP has the minimum dielectric loss factor, whereas dielectric loss factors of the three epoxy composites are larger than that of the pure epoxy resin. The decreasing order of electrical breakdown strength for the three epoxy composites and for the pure epoxy resin is as follows: NEP>MEP>NDNEP>EP. Finally, in order to explain the experimental results the aggregation interface phase was proposed. Furthermore, addition of well dispersed nano filler has proved to have a positive effect on the improvement of the dielectric properties of epoxy resin.

Experimental Evaluation on Degradation Characteristics of Epoxy Coating by Using Adhesion Force and Impedance (부착력과 임피던스를 이용한 에폭시 도장재 열화 특성에 관한 실험적 평가)

  • Nah, Hwan-Seon;Kim, Noh-Yu;Kwon, Ki-Joo;Song, Young-Chol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.2
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    • pp.149-157
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    • 2003
  • The purpose of this paper is to quantitatively investigate aging state of epoxy coating on containment structure at nuclear power plant. In order to evaluate an physical bonding of the epoxy coating, adhesion test was performed on a degraded epoxy coating on concrete specimens fabricated by accelerated aging experiment. In addition, impedance data by ultrasonic test were measured to compare with adhesion data. From almost 50 % of the specimens, aging phenomena of epoxy coating such as pin hole, blistering was discovered. To improve reliability on quality degradation of epoxy, co-relation between two kinds of different data was analyzed. By tracing co-related these data, it was possible to figure out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

Study on Hygrothermal Degradation and Corrosion Protection of Epoxy Coatings Cured by Different Amine Based Curing Agents

  • Shon, Min-Young;Kwon, Huck-Sang
    • Corrosion Science and Technology
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    • v.9 no.5
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    • pp.201-208
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    • 2010
  • Epoxy coatings cured by different amine based curing agents have been prepared. Atomic force microscopy (AFM) has been used to monitor the surface topology changes of epoxy coatings before and after hygrothermal cyclic test. The glass transition temperature ($T_g$) and coefficient of thermal expansion (CTE) of the epoxy coating were measured by Thermo-mechanical Analysis (TMA). The Electrochemical impedance spectroscopy (EIS) with hygrothermal cyclic test has been introduced to evaluate the corrosion protection of the epoxy coatings. In conclusion, thermal properties of epoxy coatings were in good agreement with the results of corrosion protection of epoxy coated carbon steel obtained result by EIS with hygrothermal cyclic test. The relationship between thermal properties, surface roughness changes and corrosion protection of epoxy coatings are discussed in this study.

Degradation of Epoxy Coating due to Aging Acceleration Effects

  • Nah, Hwan Seon;Lee, Chul Woo;Suh, Yong Pyo
    • Corrosion Science and Technology
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    • v.5 no.3
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    • pp.99-105
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    • 2006
  • This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

Dielectric Properties of Epoxy/Micro-sized Alumina Composite and of Epoxy/Micro-sized/Nano-sized Alumina Composite

  • Park, Jae-Jun
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.6
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    • pp.338-341
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    • 2015
  • Epoxy/micro-sized alumina composite was prepared, and the effects of alumina content on the dielectric properties were investigated in order to develop an insulation material for gas-insulated switchgears (GIS). Nano-sized alumina (average particle size: 30 nm) was also incorporated into the epoxy/micro-sized alumina composite. Dielectric tests were carried out in ASTM D 150, and capacitance (Cp) and dielectric loss (tanδ) were measured. The dielectric constant increased with increasing alumina content in the epoxy/micro-alumina system and the epoxy/micro-alumina/nano-alumina system. As 1,3-diglycidyl glyceryl ether (DGE) content increased, the dielectric constant decreased and dielectric loss increased. This ocurred as a result of the weak electric field enhancement due to homogeneous dispersion of micro- and nano-sized alumina particles in an epoxy composite.