Development of Epoxy-MgO Nanocomposite Material for High Voltage Electrical Insulation

Abstract

This paper investigates the dielectric properties of epoxy-MgOnanocompositematerials,focusingontheirdielectric constant and breakdown strength. The synthesis of epoxy-MgO nanocompositeswithvaryingnanoparticleconcentrationsusing magneticstirring ,ultrasonication and thermalcuring willbe done. Keyparametersincluding dielectric constantandbreak- downstrength, willbeevaluatedthroughhighvoltagetesting toassessperformanceofthematerialunderelectricalstress. Thisproject will also evaluatethecost-effectiveness ofepoxyas a polymer matrix, being more affordable and accessible than other polymers; making it suitable for large-scale applications. Additionally,theeffectsofnanoparticledispersionandinterfacial interactions on dielectric characteristics will be explored to identifyoptimalloadingconditions.Theresultingnanocomposites with enhanced dielectric properties could make them promising candidates for high voltage electrical insulation, where high dielectric strength and thermal stability are critical

Introduction

Overview

Nanocomposites are advanced materials that combine a base matrix (like epoxy) with nano-sized fillers (such as MgO nanoparticles). These fillers enhance mechanical, thermal, electrical, and dielectric properties due to their high surface area and nanoscale effects. Their applications span aerospace, automotive, electronics, and energy storage.

I. Dielectric Nanocomposites and Interparticle Distance

• In epoxy-MgO nanocomposites, adding MgO nanoparticles improves dielectric strength and breakdown resistance.

• Interparticle Distance: As the weight percentage of MgO increases, particles are spaced closer together:

  • At 1% weight: 87.47 nm

  • At 35% weight: 10.15 nm

• Closer particle spacing enhances dielectric properties, making the material more suitable for high-voltage applications.

II. Simulation Using COMSOL Multiphysics

• COMSOL is used to simulate electric field distribution under high-voltage stress.

• Geometry modeled as unit cells resembling parallel plate capacitors.

• Results showed:

  • Pure epoxy has uniform electric field.

  • Adding MgO leads to non-uniform electric field, with improved dielectric breakdown strength:

    • 2% MgO: 30.6 kV/mm

    • 5% MgO: 42.4 kV/mm

    • 10% MgO: 53.9 kV/mm

• Breakdown strength increases with MgO concentration, validating the improved insulation capability.

III. Sample Preparation

Materials Used:

• Bisphenol-A Epoxy resin (CY1300) and Hardener (HY956)

Steps:

1. Mixing: Resin and MgO nanofillers are stirred manually and magnetically at 60°C.

2. Ultrasonication: Used to break agglomerates and ensure uniform dispersion via cavitation.

3. Molding & Curing:

   • Molded into 6 cm × 1 mm discs using stainless steel molds.

   • Heated at 60°C for 4 hours in an oven.

   • Proper curing ensures solid, bubble-free samples.

Importance: Uniform filler dispersion is critical for achieving reliable dielectric performance.

IV. DC Breakdown Testing

• Samples are tested under DC high voltage while submerged in transformer oil to prevent surface flashover.

• Setup: Copper electrodes (25 mm diameter) apply voltage until failure (puncture type).

• Breakdown strength is calculated with E=VdE = \frac{V}{d}E=dV?, where:

  • V = Breakdown voltage

  • d = Sample thickness

Findings:

• Up to 8% MgO: Breakdown strength increases by 65% compared to pure epoxy.

• At 10% MgO, strength declines, suggesting overloading of fillers reduces performance.

• Optimal concentration for maximum dielectric strength is around 8% by weight.

Key Takeaways

• Epoxy-MgO nanocomposites show excellent potential for high-voltage insulation and energy storage.

• Proper nanoparticle dispersion, concentration control, and processing techniques are essential for maximizing performance.

• Simulation and experimental testing confirm that nanocomposite materials can be tailored for improved dielectric strength, with practical implications in power transmission and electronics.

Conclusion

Improvement of dielectric properties of Epoxy-MgO nanocomposites is investigated. Multiple samples of Epoxy- MgO nanocomposite at different filler loadings are prepared. HighVoltageDCbreakdowntestswereconductedtoevaluate the dielectric strength of the material at different filler con- centrations.DCbreakdownstrengthsof5wt%and8wt% arefoundtobegreaterthanthatofunfilledepoxy,while for 10 wt% the breakdown strength decreases. The maximum value of DC breakdown strength was obtained as 52.89 kV/mm at 8% filler loading. The improvement in breakdown strength is about double as that of pure epoxy. Simulation studiesalsowereconductedusingCOMSOLMultiphysics to analyse the electric field distribution in the matrix. The studyshowshowMgOnanoparticlescangreatlyimprove the electrical insulation capabilities of epoxy resins. Further research should be conducted in order to validate whether these kinds of nanocomposites can withstand long-term appli- cations in industry. Nevertheless, promising results have been obtained on these materials, which suggest that epoxy-silicon nanocomposites could transform high voltage insulation area by developing more effective and reliable materials.

References

[1] E.J.Eid,L.S.Nasrat,A.H.Shaheen“EstimationofBreakdownVoltageof Epoxy/ SiO2Nanocomposites Insulators Using Machine LearningAlgorithm,”23rdInternationalMiddleEastPowerSystemsConference(MEPCON), pp 1-6, Dec 2022 [2] Xie, Z, Li, H., Zhang, S, Gong, A, Liu, P, Peng, Z, and Wang, Q.”Research on Electrical Properties of Surface-Modified Nano-SiO2/EpoxyComposites,”IEEE International Conference on High VoltageEngineering and Application, pp 1-4, 2020 [3] A. B. Al Sawafi, N. A. Abdulzahra and J. F. Odah, ”Improvement ofDielectric and Mechanical Properties of Epoxy/SiO2 Nanocomposites,”12thInternationalConferenceonDevelopmentsineSystemsEngineer-ing (DeSE), Kazan, Russia, pp 77-82, 2019 [4] W.Wang,Q.Li,Y.Liu,H.Wang,R.WangandH.Jin,”EnhancedTher-malPropertiesofEpoxyResinComposites:TheroleofTailoringSurfaceChemistry of Nano-SiO2,”IEEE Conference on Electrical Insulationand Dielectric Phenomena (CEIDP), Vancouver, BC, Canada, pp 403-406, 2021 [5] X.Huetal,”GlasstransitiontemperaturesandChargeTransportCharac-teristics of Epoxy/SiO2 Composites,”IEEE International ConferenceonHighVoltageEngineeringandApplication(ICHVE),Beijing,China,pp 1-4, 2022 [6] S.Nakamuraetal,”Effectsoftemperatureonelectricaltreeingandpartialdischarges in epoxy/silica nanocomposites”,IEEE Transactions onDielectrics Electrical Insulation, vol. 27, no. 4, pp. 1169-1177, Aug2020 [7] M. T. Riaz et al., ”Investigation of Electrical Properties of Epoxy ResinComposite with the Surface Modification of SiO2 Nanoparticles,”2021International Conference on Computing, Electronic and ElectricalEngineering (ICE Cube), Quetta, Pakistan, pp. 1-5, 2021 [8] M.Liang,K.L.Wong,R.ShanksandV.Bansal,”Studyofdielectricandmechanical properties of epoxy/SiO2 nanocomposite prepared by differ-ent processing techniques,”2015 IEEE 11th International Conferenceon the Properties and Applications of Dielectric Materials (ICPADM), Sydney,NSW,Australia,pp.48-51,2015 [9] J.Xiang,C.Zhang,S.Wang,H.Fu,Z.XingandJ.Li,”SurfaceCoronaAgingofEpoxy/SiO2Nanocomposites,”20192ndInternationalConference on Electrical Materials and Power Equipment (ICEMPE),Guangzhou,China,pp.317-320,2019 [10] P. Karunarathna, K. Chithradewa, S. Kumara, C. Weerasekara, R. Sa-narasinghe and T. Rathnayake, ”Study on Dielectric Properties of EpoxyResin Nanocomposites,”2019 International Symposium on AdvancedElectricalandCommunicationTechnologies(ISAECT),Rome,Italy, pp.1-5,2019 [11] Siny Paul and T.K. Sindhu, “Development of epoxy-aluminiumNanocomposite Dielectric Material with Low Filler Concentration forEmbeddedCapacitorAppli-cations”,IEEETransactionsonDielectricsand Electrical Insulation, Vol. 21,No.2, pp. 460-466, 2014

Copyright

Copyright © 2025 Abhijith T Dinesh, Krishna Satheesh, Pranav K, Shona Thomas, Dr. Siny Paul, Dr. Reenu George. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.