Journal of Materials Science

, Volume 51, Issue 6, pp 2980–2990 | Cite as

Effect of compounding method and processing conditions on the electrical response of exfoliated graphite nanoplatelet/polylactic acid nanocomposite films

  • Erin M. Sullivan
  • Rosario A. Gerhardt
  • Ben Wang
  • Kyriaki Kalaitzidou
Original Paper


The focus of this study is to understand the effect of compounding method and polymer physical properties on the electrical response of exfoliated graphite nanoplatelet (GNP)/polylactic acid (PLA) nanocomposite films. Two compounding methods were employed: (i) melt mixing, followed by compression molding, and (ii) solution mixing once the polymer was dissolved in chloroform, followed by solution casting. The physical properties of the polymer, namely the crystallization characteristics were altered using two different cooling rates during compression molding: (i) slow cooling and (ii) fast cooling. The microstructure of the films was examined using scanning electron microscopy. Thermal properties, crystallization behavior, and electrical behavior were determined as a function of the GNP content, compounding method, and cooling rate using differential scanning calorimetry, X-ray diffraction, and impedance spectroscopy, respectively. It was concluded that the SC films had the lowest percolation threshold between 1 and 5 wt% of GNP, followed by the solution-cast films with percolation threshold between 5 and 8 wt% of GNP. The FC films did not percolate until a GNP content of 15 wt% was used. The vast differences in percolation thresholds are attributed to the differences in polymer matrix crystallinity and composite microstructure both in terms of microporosity and GNP dispersion/distribution within the polymer due to the different cooling rates and different compounding methods employed.


Polylactic Acid Slow Cool Percolation Threshold Crystallization Behavior Nanocomposite Film 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to thank and acknowledge the financial support provided by Cytec Engineered Materials, the Georgia Tech Manufacturing Institute, and the Jewell Family Fellowship. The authors would also like to thank the undergraduate research assistants Richard Flowers and Yun Ju Oh from the School of Materials Science & Engineering and G.W. Woodruff School of Mechanical Engineering, respectively, at Georgia Institute of Technology, for helping with the fabrication of the films.


This study was funded through research fellowships received by Erin M. Sullivan from Cytec Engineered Materials, the Georgia Tech Manufacturing Institute, and the Jewell Family Fellowship.


  1. 1.
    Zweben C (1998) Advances in composite materials for thermal management in electronic packaging. JOM-J Miner Met Mater Soc 50:47–51CrossRefGoogle Scholar
  2. 2.
    Tong XC (2011) Advanced materials for thermal management of electronic packaging. Springer, New YorkCrossRefGoogle Scholar
  3. 3.
    Ponomarenko AT, Shevchenko VG, Enikolopyan NS (1990) Formation processes and properties of conducting polymer composites. Adv Polym Sci 96:125–147CrossRefGoogle Scholar
  4. 4.
    Ou RQ, Gupta S, Parker CA, Gerhardt RA (2006) Fabrication and electrical conductivity of poly(Methyl Methacrylate) (PMMA)/Carbon Black (Cb) composites: comparison between an ordered carbon black nanowire-like segregated structure and a randomly dispersed carbon black nanostructure. J Phys Chem B 110:22365–22373CrossRefGoogle Scholar
  5. 5.
    Kalaitzidou K, Fukushima H, Askeland P, Drzal LT (2008) The nucleating effect of exfoliated graphite nanoplatelets and their influence on the crystal structure and electrical conductivity of polypropylene nanocomposites. J Mater Sci 43:2895–2907. doi: 10.1007/s10853-007-1876-3 CrossRefGoogle Scholar
  6. 6.
    Sullivan E, Oh Y, Gerhardt R, Wang B, Kalaitzidou K (2014) Understanding the effect of polymer crystallinity on the electrical conductivity of exfoliated graphite nanoplatelet/polylactic acid composite films. J Polym Res 21:1–9CrossRefGoogle Scholar
  7. 7.
    Aharony A, Stauffer D (2003) Introduction to percolation theory. Taylor & Francis, LondonGoogle Scholar
  8. 8.
    Gokturk HS, Fiske TJ, Kalyon DM (1993) Effects of particle-shape and size distributions on the electrical and magnetic-properties of nickel/polyethylene composites. J Appl Polym Sci 50:1891–1901CrossRefGoogle Scholar
  9. 9.
    Jing X, Zhao W, Lan L (2000) The effect of particle size on electric conducting percolation threshold in polymer/conducting particle composites. J Mater Sci Lett 19:377–379. doi: 10.1515/polyeng-2014-0206 CrossRefGoogle Scholar
  10. 10.
    Clingerman ML, Weber EH, King JA, Schulz KH (2003) Development of an additive equation for predicting the electrical conductivity of carbon-filled composites. J Appl Polym Sci 88:2280–2299CrossRefGoogle Scholar
  11. 11.
    Chodak I, Krupa I (1999) “Percolation Effect” and mechanical behavior of carbon black filled polyethylene. J Mater Sci Lett 18:1457–1459. doi: 10.1016/j.eurpolymj.2014.03.013 CrossRefGoogle Scholar
  12. 12.
    Kalaitzidou K, Fukushima H, Drzal LT (2010) A route for polymer nanocomposites with engineered electrical conductivity and percolation threshold. Materials 3:1089–1103CrossRefGoogle Scholar
  13. 13.
    Lunt J (1998) Large-scale production, properties and commercial applications of polylactic acid polymers. Polym Degrad Stab 59:145–152CrossRefGoogle Scholar
  14. 14.
    Drumright RE, Gruber PR, Henton DE (2000) Polylactic acid technology. Adv Mater 12:1841–1846CrossRefGoogle Scholar
  15. 15.
    Murariu M, Dechief AL, Bonnaud L, Paint Y, Gallos A, Fontaine G, Bourbigot S, Dubois P (2010) The production and properties of polylactide composites filled with expanded graphite. Polym Degrad Stab 95:889–900CrossRefGoogle Scholar
  16. 16.
    Jiang X, Drzal LT (2012) Multifunctional high-density polyethylene nanocomposites produced by incorporation of exfoliated graphene nanoplatelets 2: crystallization, thermal and electrical properties. Polym Compos 33:636–642CrossRefGoogle Scholar
  17. 17.
    Kalaitzidou K, Fukushima H, Drzal LT (2007) Multifunctional polypropylene composites produced by incorporation of exfoliated graphite nanoplatelets. Carbon 45:1446–1452CrossRefGoogle Scholar
  18. 18.
    Petersson L, Oksman K (2006) biopolymer based nanocomposites: comparing layered silicates and microcrystalline cellulose as nanoreinforcement. Compos Sci Technol 66:2187–2196CrossRefGoogle Scholar
  19. 19.
    Ray SS, Yamada K, Okamoto M, Fujimoto Y, Ogami A, Ueda K (2003) New polylactide/layered silicate nanocomposites. 5. designing of materials with desired properties. Polymer 44:6633–6646CrossRefGoogle Scholar
  20. 20.
    Byun Y, Whiteside S, Thomas R, Dharman M, Hughes J, Kim YT (2012) The effect of solvent mixture on the properties of solvent cast polylactic acid (PLA) film. J Appl Polym Sci 124:3577–3582CrossRefGoogle Scholar
  21. 21.
    Rhim JW, Mohanty AK, Singh SP, Ng PKW (2006) Effect of the processing methods on the performance of polylactide films: thermocompression versus solvent casting. J Appl Polym Sci 101:3736–3742CrossRefGoogle Scholar
  22. 22.
    Krikorian V, Pochan DJ (2004) Unusual crystallization behavior of organoclay reinforced poly(L-Lactic Acid) nanocomposites. Macromolecules 37:6480–6491CrossRefGoogle Scholar
  23. 23.
    Hoogsteen W, Postema AR, Pennings AJ, Tenbrinke G, Zugenmaier P (1990) Crystal-structure, conformation, and morphology of solution-spun poly(L-Lactide) fibers. Macromolecules 23:634–642CrossRefGoogle Scholar
  24. 24.
    Gopakumar TG, Page D (2004) polypropylene/graphite nanocomposites by thermo-kinetic mixing. Polym Eng Sci 44:1162–1169CrossRefGoogle Scholar
  25. 25.
    Pluta M, Galeski A (2002) Crystalline and supermolecular structure of polylactide in relation to the crystallization method. J Appl Polym Sci 86:1386–1395CrossRefGoogle Scholar
  26. 26.
    Hebert JS, Wood-Adams P, Heuzey MC, Dubois C, Brisson J (2013) Morphology of polylactic acid crystallized during annealing after uniaxial deformation. J Polym Sci Part B 51:430–440CrossRefGoogle Scholar
  27. 27.
    Langford JI, Wilson AJC (1978) Scherrer after 60 years-survey and some new results in determination of crystallite size. J Appl Crystallogr 11:102–113CrossRefGoogle Scholar
  28. 28.
    Ezquerra TA, Connor MT, Roy S, Kulescza M, Fernandes-Nascimento J, Baltá-Calleja FJ (2001) Alternating-current electrical properties of graphite, carbon-black and carbon-fiber polymeric composites. Compos Sci Technol 61:903–909CrossRefGoogle Scholar
  29. 29.
    Gerhardt RA (2005) Impedance spectroscopy and mobility spectra. In: Bassani F, Liedl GL, Wyder P (eds) Encyclopedia of condensed matter physics. Elsevier, Oxford, pp 350–363CrossRefGoogle Scholar
  30. 30.
    Sandler JKW, Kirk JE, Kinloch IA, Shaffer MSP, Windle AH (2003) Ultra-low electrical percolation threshold in carbon-nanotube-epoxy composites. Polymer 44:5893–5899CrossRefGoogle Scholar
  31. 31.
    Lewis TJ (1990) Charge transport, charge injection and breakdown in polymeric insulators. J Phys D 23:1469–1478CrossRefGoogle Scholar
  32. 32.
    Ramanathan T, Stankovich S, Dikin DA, Liu H, Shen H, Nguyen ST, Brinson LC (2007) Graphitic nanofillers in PMMA nanocomposites—an investigation of particle size influence on nanocomposite and dispersion and their properties. J Polym Sci Part B 45:2097–2112CrossRefGoogle Scholar
  33. 33.
    Cho D, Lee S, Yang GM, Fukushima H, Drzal LT (2005) Dynamic mechanical and thermal properties of phenylethynyl-terminated polyimide composites reinforced with expanded graphite nanoplatelets. Macromol Mater Eng 290:179–187CrossRefGoogle Scholar
  34. 34.
    Mackay ME, Dao TT, Tuteja A, Ho DL, Van Horn B, Kim HC, Hawker CJ (2003) Nanoscale effects leading to non-einstein-like decrease in viscosity. Nat Mater 2:762–766CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • Erin M. Sullivan
    • 1
  • Rosario A. Gerhardt
    • 1
  • Ben Wang
    • 1
    • 2
  • Kyriaki Kalaitzidou
    • 1
    • 3
  1. 1.School of Materials Science and EngineeringGeorgia Institute of TechnologyAtlantaUSA
  2. 2.Georgia Tech Manufacturing InstituteGeorgia Institute of TechnologyAtlantaUSA
  3. 3.George W. Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlantaUSA

Personalised recommendations