• Composites Research
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• v.37 no.5
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• pp.393-401
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• 2024

Epoxy is a thermosetting polymer with excellent properties such as heat and chemical resistance, making them essential in various industrial fields including electronics. The performance of epoxy is highly dependent on the type of curing agent used. Among them, sulfonium-based latent curing agents are notable for their fast curing speed, high curing hardness, and specificity to certain temperatures, making them attractive for manufacturing anisotropic conductive films in electronic materials where single-component epoxy is required. However, sulfonium-based latent curing agents face challenges in industrial application due to issues with low yield and purity. This study optimized the synthesis conditions for benzyl and naphthyl-type sulfonium curing agents (B-Sul⁺SbF6^-, N-Sul⁺NCyF^-, N-Sul⁺NFSI^-). By adjusting reaction time, reaction temperature, and reactant ratios, yield was maximized, significantly reducing both reaction time and temperature. The three optimized curing agents were evaluated for their thermal and mechanical properties to assess curing behavior and storage stability. The results confirmed that stable curing performance was maintained even after mixing. This study aims to expand the industrial applicability of sulfonium curing agents.

• Composites Research
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• v.33 no.2
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• pp.55-60
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• 2020

A study on the heating behavior and adhesion property of structural epoxy adhesive through induction heating have been conducted. An adhesive for induction heating was manufactured through mixing with nano and micro sized Fe₃O₄. From the results, it was observed that induction heating is less affected by adherend (GFRP) thickness than oven heating. The heating rate of Fe₃O₄ embedded epoxy adhesive using induction heating much higher than that of oven curing process and it is more appreciable when the contents of Fe₃O₄ increased. Furthermore, adhesion strength increased with increase of Fe₃O₄ particle contents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.455-456
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• 2007

Optically transparent, highly conductive coating have been major theme of thin film science efforts for some years. In this work, t-MWNT(thin Multi-walled Carbon Nanotubes) are acid treated, then the stable dispersion of t-MWNTs in polar solvent such as alcohols, was achieved by sonication. The transparent conducting films are prepared using the one component solution of t-MWNT/epoxy binder via spray coating on glass substrate. The characterization of acid treated t-MWNTs was performed by Raman spectrometer. The opto-electrical properties of conducting films are analyzed by the binder concentration, and the effect of co-solvent on the compatibility and dispersibility of one component t-MWNT/epoxy binder solutions are discussed.

• Applied Chemistry for Engineering
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• v.7 no.5
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• pp.963-969
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• 1996

Cure characteristics of DGEBA(diglycidyl ether of bisphenol A)/dicy(dicyandiamide) system containing diuron(3-(3,4-dichloro phenyl) -1,1-dimethylurea) as an accelerator was investigated. The system has shelf life of six months because dicy is insoluble in liquid/solid resins at room temperature. It is generally known that dicy is an adequate curing agent for one component adhesive due to its highly latent property. With increasing the amount of added dicy, reaction heat of DGEBA/dicy system increased and degree of conversion was not varied. For DGEBA/dicy/diuron system, cure temperature decreased about $40^{\circ}C$ and cure reaction became fast by the addition of diuron which activates dicy. $T_g$ of the mixed resin decreased with the amount of accelerator. which was interpreated with molecular structure forming loose chain. Cure kinetics of DGEBA/dicy and DGEBA/dicy/diuron system were explained using Kamal's autocatalytic reaction model. The effect of acceleration was confirmed with that reaction model.