• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.249-249
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• 2009

we have studied that a effect depending on dielectric properties of epoxy resin mixing filler nano/micro. When compare with nano/micro composite and virgin, the nano/micro composite is better than virgin. A specimen mixing nano/micro is changed as temperate, however the width of change is low.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.153-153
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• 2009

In the study the volume resistivity Characteristics of epoxy resin using nano and micro filler, nano and micro filler are made from insulating material epoxy resin using for transformer equipment and molding several devices as changing amount of addition of diameter 12 [nm] and 7 [${\mu}m$] $SiO_2$, we measured volume resistivity of nano and micro filler by High Resistance Meter(4329A). As the result of measurement, When is micro filler, the volume resistivity continuously increased over 80 [$^{\circ}$].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.225-225
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• 2009

In this study, Nano and micro-filler mixture composites were fabricated by fixed value of $SiO_2$ nano-filler 0.4 [wt%] according to increase of $SiO_2$ micro-filler [wt%] from 1 to 10. Composites with a good dispersion of mixed $SiO_2$ Nano and micro-particles in the epoxy resins were prepared and experiments were performed to measure the dielectric breakdown strength properties with various temperature and thickness. The dielectric strength properties are compared and analyzed with respect to nano/micro-composites filled with $SiO_2$ fillers less than properties obtained for nanocomposites.

• Bulletin of the Korean Chemical Society
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• v.33 no.9
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• pp.2949-2954
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• 2012

Nano ZnO with an average size of 8 nm was prepared by thermal decomposition of zinc oxalate at $450^{\circ}C$. A series of based composite polymer electrolyte PEO-$LiClO_4$ and nano ZnO as a filler have been synthesized using solution cast technique, with varying the filler ratio systematically. XRD, DSC and FTIR studies have been conducted to investigate the structure and interaction of different groups in the composite polymer electrolyte. Effect of nano ZnO ceramic filler concentration on the structure of composites and their electrical properties (DC-conductivity, AC-conductivity, dielectric constant, dielectric loss and impedance) at different frequencies and temperatures was studied. Melting temperature ($T_m$) of PEO decreased with the addition of both $LiClO_4$ salt and nano ZnO filler due to increasing the amorphous state of polymer. All composite samples showed an ionic conductivity. The maximum room temperature ionic conductivity is found for $(ZnO)_{0.5}(PEO)_{12}(LiClO_4)$ composite sample. All the results are correlated and discussed.

• Journal of the Semiconductor & Display Technology
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• v.9 no.2
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• pp.33-39
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• 2010

The moisture absorption properties such as diffusion coefficient and moisture content ratio of liquid type epoxy resin systems with the filler were investigated. Bisphenol A type and Bisphenol F type epoxy resin, Kayahard MCD as hardener and 2-methylimidazole as catalyst were used in these epoxy resin systems. The nano-sized spherical type fused silica as filler were used in order to study the moisture absorption properties of these liquid type epoxy encapsulant according to the change of filler size. The temperature of glass transition (Tg) of these epoxy resin systems was measured using Dynamic Scanning Calorimeter (DSC), and the moisture absorption properties of these epoxy resin systems 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 systems were calculated in terms of modified Crank equation based on Ficks' law. An increase of Tg and diffusion coefficient with filler size in these systems can be observed, which are attributed to the increase of free volume with Tg. The change of maximum moisture absorption ratio according to the filler size and filler content cannot be observed; however, the diffusion coefficients of these systems decreased with filler content. The diffusion via free volume is dominant in the epoxy resin systems with low nano-sized filler content; however, the diffusion with the interaction of absorption according the increase of the filler surface area is dominant in the liquid type epoxy encapsulant with high nano-sized filler content.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.150-150
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• 2009

In this paper, various kinds of epoxy based nanocomposites were made and AC breakdown properties of nano-$TiO_2$ and micro-silica filler mixture of epoxy based composites were studied by sphere to sphere electrode. Moreover, nano- and micro-filler combinations were adopted as an approach toward practical application of nanocomposite insulating materials. AC breakdown test was performed at room temperature $(25^{\circ}C)$, $80^{\circ}C$ and $100^{\circ}C$. The result shows breakdown strength about non-filled, nano-scale $TiO_2$, micro-scale silica and nano-$TiO_2$, micro-silica filled epoxy composites.

• Elastomers and Composites
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• v.55 no.4
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• pp.306-313
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• 2020

To investigate the reinforcing effects of functional fillers in nitrile rubber (NBR) materials, high-structure carbon black (HS45), coated calcium carbonate (C-CaCO3), silica (200MP), and multi-walled carbon nanotubes (MWCNTs) were used as functional filler, and carbon black (SRF) as a common filler were used for oil-resistant rubber. The curing and mechanical properties of HS45-, 200MP-, and MWCNT-filled NBR compounds were improved compared to those of the SRF-filled NBR compound. The reinforcing effect also increased with a decrease in the particle size of the fillers. The C-CaCO3-filled NBR compound exhibited no reinforcing effect with increasing filler concentration because of their large primary particle size (2 ㎛). The reinforcing behavior based on 100% modulus of the functional filler based NBR compounds was compared by using several predictive equation models. The reinforcing behavior of the C-CaCO3-filled NBR compound was in accordance with the Smallwood-Einstein equation whereas the 200MP- and MWCNT-filled NBR compounds fitted well with the modified Guth-Gold (m-Guth-Gold) equation. The SRF- and HS45-filled NBR compounds exhibited reinforcing behavior in accordance with the Guth-Gold and m-Guth-Gold equations, respectively, at a low filler content. However, the values of reinforcement parameter (100Mf/100Mu) of the SRF- and HS45-filled NBR compounds were higher than those determined by the predictive equation model at a high filler content. Because the chains of SRF composed of spherical filler particles are similarly changed to rod-like filler particles embedded in a rubber matrix and the reinforcement parameter rapidly increased with a high content of HS45, the higher-structured filler. The reinforcing effectiveness of the functional fillers was numerically evaluated on the basis of the effectiveness index (��SRF/��f) determined by the ratio of the volume fraction of the functional filler (��f) to that of the SRF filler (��SRF) at three unit of reinforcing parameter (100Mf/100Mu). On the basis of their effectiveness index, MWCNT-, 200MP-, and HS45-filled compounds showed higher reinforcing effectiveness of 420%, 70%, and 20% than that of SRF-filled compound, respectively whereas C-CaCO3-filled compound exhibited lower reinforcing effectiveness of -50% than that of SRF-filled compound.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.92-92
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• 2010

In this paper, the test is performed on MgO, which is used as a filler in epoxy additives, respectively (0, 1.0, 3.0, 5.0, 7.0, 10 [wt%]) for HVDC(high voltage direct current) submarine cable insulating material to improve electrical properties of epoxy resin in high temperature. The breakdown strength due to increasing amount of filler increased to 5.0 [wt%] by the effects of the Coulomb blockade. However, it is confirmed that strength of dielectric breakdown decreased because the filler functioned as impurities and affected the breakdown when filler additive exceeded by 5.0 [wt%] or more. We have found that the highest dielectric breakdown strength of specimen added 5.0 wt% at $25^{\circ}C$, and is more increased approximately 13.7 [%] than virgin specimen.

• Macromolecular Research
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• v.10 no.6
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• pp.369-372
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• 2002

The use of ZnO and stearic acid is very well known in sulfenamide accelerated sulfur vulcanization of diene elastomers. Zn-ion coated nano filler has been developed and tested, in styrene-butadiene rubber (SBR) as sulfur vulcanizing activator cum reinforcing filler. In this study Zinc oxide has been replaced by the Zn-ion coated nano silica filler with an aim to study the dual role of this nanofiller in SBR. The presence of Zn-ion on the nano silica filler surface activates the sulfur vulcanization by involving Zn++ in to the sulfurating complex formed with thiazole from sulfenamide. The increase of Zn-ion, on the nanofiller, decrease the scorch safety of the elastomer compound but increase the tensile strength, state of cure and tear strength and attain maximum at its 10% level. The presence of stearic acid increases the rate of vulcanization. Replacement of stearic acid with mono-stearate, however, increases the vulcanization rate but decrease the ultimate state of cure. A mechanistic scheme involving dual function of this nanofiller has been suggested.

• Korean Journal of Materials Research
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• v.21 no.2
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• pp.100-105
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• 2011

The relative viscosity was measured at different filler loadings for a cycloaliphatic epoxy resin and hexahydro-4-methylphthalic anhydride hardener system filled with micro/nano hybrid silica. Various empirical models were fitted to the experimental data and a fitting parameter such as critical filler fractions (${\phi}_{max}$) was estimated. Among the models, the Zhang-Evans model gave the best fit to the viscosity data. For all the silica loadings used, ln (relative viscosity) varied linearly with filler loadings. Using the Zhang-Evans model and the linearity characteristics of the viscosity change, simple methods to predict the relative viscosity below ${\phi}_{max}$ are presented in this work. The predicted viscosity values from the two methods at hybrid silica fractions of $\phi$ = 0.086 and 0.1506 were confirmed for a micro:nano = 1:1 hybrid filler. As a result, the difference between measured and predicted values was less than 11%, indicating that the proposed predicting methods are in good agreement with the experiment.