polymer nanocomposite innovating on insulating materials
TRANSCRIPT
TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERINGIEEJ Trans 2009; 4: 8–9Published online in Wiley InterScience (www.interscience.wiley.com). DOI:10.1002/tee.20348
Review Paper
Polymer Nanocomposite Innovating on Insulating Materials
Toshikatsu Tanakaa
Received 18 February 2008
1. Introduction
Polymer nanocomposite was invented at the end of the 20thcentury. Currently, attention is being focused on this materialas an innovative one, which will mark the 21st century in thefield of materials science and engineering. Although originallydeveloped as engineering plastics, this material is currently rec-ognized as very good dielectric/insulating materials, attractingoriginal, excellent research projects. From the industrial view-point, polymer nanocomposite is attractive in that addition ofa small amount of inorganic nanofiller to organic polymer willgreatly alter the polymer performance. Also it is academicallyattractive, creating a challenge to a new, mesoscopic character-istic research of inorganic/organic boundary.
2. Polymer Nanocomposite
2.1. Formation Polymer nanocomposite is formedby (i) interlayer insertion, (ii) sol-gel, (iii) in-situ, or (iv) ultra-fine particle direct dispersion method, where a small amountof nanofiller in several wt% is uniformly dispersed in polymer.One of the figures given above for informational purposes showthat an ultrafine particle direct dispersion process is used todisperse nanosilica (about 40 nm in diameter) in epoxy, theother showing the scanning electron microscope (SEM) photoof fractured surface of nanocomposite.
2.2. Dielectric/insulating characteristics Afterreview of available data, nanocomposite has been found to haveexcellent characteristics with regard to permittivity, dielectricdissipation factor, low electric field conductivity, space charge,high electric field conduction, high electric field electrolumi-nescence, dielectric break-down field, treeing resistance, par-tial discharge resistance, and tracking resistance. Among thesecharacteristics, what is remarkable is enhanced partial chargeresistance for epoxy and polyimide, reduced space charge forpolyethylene, and prolonged life in tree break-down V-t char-acteristics for various polymers.
2.3. Research of interfaces Nanocomposite char-acteristics result from the interface between nanofiller and poly-mer matrix. Research of interfaces advocates multicore modelsbased on physicochemical consideration, which is accompaniedby molecular dynamics simulation research.
a Correspondence to: Toshikatsu Tanaka. E-mail: [email protected]
Direct mixing dispersion machine
Material formation
SEM image:
Fractured surface ofnanocomposite
Use mixing dispersion machine to mix nano-filler added topolymer and uniformly disperse to form nanocomposite.
Nano particle:some 10 nmin particle size
Bound layer: several layers
Modeling
Huge interface causes meso-scopiccharacteristics to appear
Interfacial multi-coremodel
Periodic boundary condition is entered
Molecular dynamicssimulation
Bound layer bulk
Power electronics field
BulkBulkBasic researchmodeling
Field of Application
Electric power field
Solid insulated heavy electric apparatus
Source: Ttoshiba Review, December 2006 issueToshiba Mold Transformer Catalog
Merit: compact size
Communications field Automotive field
Courtesy of Fuji Electric AdvancedTechnology Co., LTD.
High-density installation
Expoxy casting parts
300kVA transformerEnhancement bynanocomposite technology
Desired propertiesfor next industrialinsulating material
24/36kV switchgear
- Thermal resistance- Mechanical strength- Fracture toughness- Insulation properties- Productivity
High-density installation Utilization of high temperatures
Fig. 1 Formation, property research, and application develop-ment of nanocomposite
2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
POLYMER NANOCOMPOSITE INNOVATING ON INSULATING MATERIALS
2.4. Field of application Nanocomposite is appliedto various fields, including electric power, electronics, informa-tion technologies, and automotive industries. Figure 1 showssome examples of applications, attracting significant attentionin mold high-voltage insulation, direct current high-voltagecable, power electronics insulation, and high-density installa-tion electronic circuit fields.
3. Conclusion
As mentioned above, polymer nanocomposite is expected toplay a role as innovative insulating material in the future.
9 IEEJ Trans 4: 8–9 (2009)