• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.352-356
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• 2014

PDMS modified epoxy resin with epoxy group (EMPDMS) was prepared from the reaction of ${\alpha},{\omega}$-aminopropylpolydimethylsiloxane and diglycidyl ether of bisphenol-A (DGEBA) based epoxy resin, and PDMS modified epoxy hybrid compound (EMPDMSH) was prepared by introducing alkylesteraminopropyl alkoxy silane to EMPDMS. Their structures were characterized using FT-IR, $^1H$-NMR and $^{29}Si$-NMR. Coating materials were prepared by mixing EMPDMSH base and solvent. Physical properties of the coating materials coated on epoxy/glass fiber composite film were measured according to the content of PDMS in EMPDMSH. Contact angle of coating film was increased 30 to 71 degree. Adhesive property of coating film was 5B degree better then epoxy or acrylate coating materials, and surface roughness was decreased as increasing in EMPDMSH.

• Carbon letters
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• v.14 no.1
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• pp.1-13
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• 2013

Carbon nanotubes (CNTs) are increasingly attracting scientific and industrial interest because of their outstanding characteristics, such as a high Young's modulus and tensile strength, low density, and excellent electrical and thermal properties. The incorporation of CNTs into polymer matrices greatly improves the electrical, thermal, and mechanical properties of the materials. Surface modification of CNTs can improve their processibility and dispersion within the composites. This paper aims to review the surface modification of CNTs, processing technologies, and mechanical and electrical properties of CNT-based epoxy composites.

• Journal of the Semiconductor & Display Technology
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• v.21 no.2
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• pp.57-67
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• 2022

The curing characteristics of naphthalene type epoxy resin systems according to the change of curing agent were investigated to develop a new next-generation EMC(Epoxy Molding Compound) with excellent warpage characteristics, low thermal expansion, and excellent fluidity for WLP(Wafer Level Package). As epoxy resins, DGEBA, which are representative bisphenol type epoxy resins, NE-16, which are the base resins of naphthalene type epoxy resins, and NET-OH, NET-MA, and NET-Epoxy resins newly synthesized based on NE-16 were used. As a curing agent, DDM (Diamino Diphenyl Methane) and CBN resin with naphthalene moiety were used. The curing reaction characteristics of these epoxy resin systems with curing agents were analyzed through thermal analysis experiments. In terms of curing reaction mechanism, DGEBA and NET-OH resin systems follow the nth curing reaction mechanism, and NE-16, NET-MA and NET-Epoxy resin systems follow the autocatalytic curing reaction mechanism in the case of epoxy resin systems using DDM as curing agent. On the other hand, it was found that all of them showed the nth curing reaction mechanism in the case of epoxy resin systems using CBN as the curing agent. Comparing the curing reaction rate, the epoxy resin systems using CBN as the curing agent showed a faster curing reaction rate than them with DDM as a hardener in the case of DGEBA and NET-OH epoxy resin systems following the same nth curing reaction mechanism, and the epoxy resin systems with a different curing mechanism using CBN as a curing agent showed a faster curing reaction rate than DDM hardener systems except for the NE-16 epoxy resin system. These reasons were comparatively explained using the reaction rate parameters obtained through thermal analysis experiments. Based on these results, low thermal expansion, warpage reduction, and curing reaction rate in the epoxy resin systems can be improved by using CBN curing agent with a naphthalene moiety.

• Composites Research
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• v.29 no.4
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• pp.223-229
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• 2016

SiC nanoparticles were used to increase flexural properties of polymer matrix. This study was to manufacture huge concentration SiC nanoparticle/epoxy composites and to evaluate the dispersion. During mixing SiC nanoparticle and epoxy, 20 wt% SiC nanoparticle in total composites was used with both stirrer and sonication equipment together. Mixing speed and dispersion were improved with the method by using both stirrer and sonication equipment at the same time via mechanical test and FE-SEM. Based on the results, modeling of SiC nanoparticle dispersion could be established. Ultimately, unidirectional carbon fiber reinforced composites was manufactured using 20 wt% SiC nanoparticle/epoxy. Mechanical property of CFRP using dual stirrer and sonication mixing method was better than composites by single sonication mixing method.

• Composites Research
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• v.29 no.4
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• pp.125-131
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• 2016

In case of CNT mixing with epoxy, epoxy matrix needs to be diluted. This work studied the effect of the dilution condition of epoxy on CNT dispersion. The optimum solvent condition using acetone and DMF was found via mechanical and solubility methods which affects, the epoxy performance. The dispersion using acetone was better than the DMF and thus higher mechanical properties. Four mixing types of CNT particle were performed. To verify the effects of each step between dilution and dispersion, the dispersion between epoxy and CNT was evaluated via the electrical resistance and optical methods. The optimum dispersion was obtained via mechanical test and thermal analysis by DSC. Among four types, the best was to disperse CNT after epoxy and hardeners were diluted respectively.

• Journal of Conservation Science
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• v.30 no.1
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• pp.103-109
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• 2014

This study aimed to develop materials to compensate for problems of restoration for lost parts and material problems in the conservation treatment. First, there are several problems with existing materials as follows: secondary damage due to the high shrinkage rate and low adhesive strength, sense of difference due to the severe yellowing, remelting due to irreversibility of materials, processability due to the high strength, sag due to the prolonged setting time in the work process and surface contamination of artifacts due to tools or gloves. In order to solve these problems, this study set developmental goals after understanding the types and physical properties based on epoxy resin among the currently used restoration materials of pottery and earthenware. The developed epoxy resin is epoxy putty, which is cured within 5 minutes, for earthenware restoration. In the earthenware restoration method, the epoxy putty enhanced the workability by quickly curing in paste form and compensated disadvantages such as surface contamination. In addition, the use of white micro-balloon for the epoxy stock solution made coloring easier and weight lighter, and a restoration material with low shrinkage and superior processability was developed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1322-1329
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• 2018

In this paper, the reliability test of three kinds of epoxy resin for GIS Spacer, which is a high voltage based heavy electric machine, AC electrical treeing experiments were performed. Three types of epoxy resins, Araldite B41, CT 5531 CI and B46, have slight viscosity differences. An non-uniform electric field, E = 1149.4 kV/mm, as the needle to plate electrode, a power source with a frequency of 1 kHz was applied to the tree electrode for accelerated deterioration. The treeing phenomena of the three kinds of epoxy resin all initiated, propagated, and destroyed by the branch tree. Epoxy Resin B46 was 145 times longer than B41 and 53 times longer than CT 5531CI. I think that the choice of epoxy resin is very important in choosing high voltage heavy electric machine insulation materials.

• Composites Research
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• v.28 no.6
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• pp.361-365
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• 2015

The influence of MWCNTs on fracture toughness properties of MWCNTs/Nickel-Pitch Fibers/epoxy composites (MWCNTs/Ni-PFs/epoxy) was investigated according to MWCNTs content. Nickel-Pitch-based carbon fibers (Ni-PFs) were prepared by electroless nickel-plating. The surface properties of Ni-PFs were determined by scanning electron microscopy (SEM) and X-ray photoelectron spectrometry (XPS). The fracture toughness of MWCNTs/Ni-PFs/epoxy was assessed by critical stress intensity factor ($K_{IC}$) and critical strain energy release rate ($G_{IC}$). From the results, it was found that the fracture toughness properties of MWCNTs/Ni-PFs/epoxy were enhanced with increasing MWCNTs content, whereas the value decreased above 5 wt.%. MWCNTs content. This was probably considered that the MWCNTs entangled with each other in epoxy due to an excess of MWCNTs.

• 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.

• Textile Coloration and Finishing
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• v.9 no.6
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• pp.79-86
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• 1997

The microcapsule for thermochromism is based on the polymerization reaction between epoxy resin and amine curing agent. The preparation process of microcapsule is based on dissolving or dispersing a hydrophobic core materials[one-dye-black(OBD), bis-phenol A(BPA), cetyl alcohol] in an aqueous solution of gelatin, epoxy resin and isophorondiamine(IPDA) ; the gelatin and IPDA used as a dispersion stabilizer and an hardening agent, respectively. The structures of epoxy resin and microcapsule materials have been analyzed by FT-IR and UV/Vis spectra. The mean diameter and size distribution of microcapsule are 1.46~1.75${\mu}{\textrm}{m}$ and 1.42, respectively. The DSC thermograms of microcapsules indicated 2 kinds of endothermic peaks at 47 and 322$^{\circ}C$. This is possibly corresponding to the melting peak of core material and wall meterial. These microcapsules are applied to the fabric by printing. Complex finished fabric showed a good wear resistance on rubbing test and the print pattern to the cotton fabric showed a reversible thermochromism ; ${\mu}_{max}$ are 580 nm below 4$0^{\circ}C$ and 276.5nm above 4$0^{\circ}C$ in ethanol/water(2/8), respectively.