Polyamide 6/reduced graphene oxide nano-composites prepared via reactive melt processing: formation of crystalline/network structure and electrically conductive properties

  • Meng Xiang
  • Chengjie Li
  • Lin YeEmail author


In this work, polyamide 6 (PA6)/reduced graphene oxide (RGO)- toluene-2,4-diisocyanate (TDI) composites were fabricated by reactive melt processing, and effect of formation of crystalline/network structure on electrically conductive properties of the composites was studied. The molecular bridge effect of exfoliated RGO-TDI resulted in the homogeneous dispersion of RGO in PA6 matrix. Crystallization analysis shows that RGO facilitated the crystallization of PA6 matrix mainly via accelerating the generation of crystal nucleus, reaching maximum of Xc and minimum of crystal grain size upon RGO level of 1.66 vol.%, which confirmed the formation of most perfect crystalline structure. According to the dynamic rheological analysis, both frequency-independence of G’ and sharply reduce phase angle at low-frequency region with RGO loading level of 1.66 vol.% indicate the transition from liquid-like to solid-like rheological behavior, where terminal to non-terminal transition as well as Cole-Cole arc and rapidly increasing entanglement density confirm the formation of percolation network structure with RGO as a crosslinking center. Corresponding to the analysis above, the electrical conductivity of the nano-composites increased rapidly to the equilibrium value, resulting from the formation of perfect conductive network at RGO loading level of 1.66 vol.%, which was confirmed by TEM analysis.

Graphical abstract

The percolation network formed at 1.66 vol.% RGO loading level, leading to the rapid increase of electrical conductivity of PA6.


Polyamide 6/RGO nano-composites Crystallization behaviour Dynamical rheological behavior Percolation network structure Electrically conductive properties 



This work was supported by Fundamental Research Project for Changzhou of China (CJ20180056), and Science and Technology Project of Sichuan Province (2019YFG0240).


  1. 1.
    Pan B, Zhang S, Li W, Zhao J, Liu J, Zhang Y, Zhang Y (2012). Wear 294:395CrossRefGoogle Scholar
  2. 2.
    Wang W, Meng L, Huang Y (2014) Hydrolytic degradation of monomer casting nylon in subcritical water. Polym Degrad Stab 110:312–317CrossRefGoogle Scholar
  3. 3.
    Krupa I, Miková G, Novák I, Janigová I, Nógellová Z, Lednický F, Prokeš J (2007) Electrically conductive composites of polyethylene filled with polyamide particles coated with silver. Eur Polym J 43:2401–2413CrossRefGoogle Scholar
  4. 4.
    Hochberg A, Versieck J (2001) Shielding for EMI and antistatic plastic resins with stainless steel fibres. Plastics Additives & Compounding 3:24–28CrossRefGoogle Scholar
  5. 5.
    Chodak I, Omastova M, Pionteck J (2001) Relation between electrical and mechanical properties of conducting polymer composites. J Appl Polym Sci 82:1903–1906CrossRefGoogle Scholar
  6. 6.
    Geim AK, Novoselov KS (2007) The rise of graphene. Nat Mater 6:183–191CrossRefGoogle Scholar
  7. 7.
    Edwards RS, Coleman KS (2013) Graphene synthesis: relationship to applications. Nanoscale 5:38–51CrossRefGoogle Scholar
  8. 8.
    Zhang Y, Heo Y-J, Son Y-R, In I, An K-H, Kim B-J, Park S-J (2019) Recent advanced thermal interfacial materials: A review of conducting mechanisms and parameters of carbon materials. Carbon 142:445–460CrossRefGoogle Scholar
  9. 9.
    Hu Y, Liu X, Tian L, Zhao T, Wang H, Liang X, Zhou F, Zhu P, Li G, Sun R, Wong C-P (2018) Multidimensional Ternary Hybrids with Synergistically Enhanced Electrical Performance for Conductive Nanocomposites and Prosthetic Electronic Skin. ACS Appl Mater Interfaces 10:38493–38505CrossRefGoogle Scholar
  10. 10.
    Yang H, Yao X, Yuan L, Gong L, Liu Y (2019) Strain-sensitive electrical conductivity of carbon nanotube-graphene-filled rubber composites under cyclic loading. Nanoscale 11:578–586CrossRefGoogle Scholar
  11. 11.
    Das SK (2018) Graphene: A Cathode Material of Choice for Aluminum-Ion Batteries. Angew Chem Int Ed 57:16606–16617CrossRefGoogle Scholar
  12. 12.
    Gao B, Zhang R, He M, Sun L, Wang C, Liu L, Zhao L, Cui H, Cao A (2016) Effect of a multiscale reinforcement by carbon fiber surface treatment with graphene oxide/carbon nanotubes on the mechanical properties of reinforced carbon/carbon composites. Compos A: Appl Sci Manuf 90:433–440CrossRefGoogle Scholar
  13. 13.
    Yang Z, Tian J, Yin Z, Cui C, Qian W, Wei F (2019) Carbon nanotube- and graphene-based nanomaterials and applications in high-voltage supercapacitor: A review. Carbon 141:467–480CrossRefGoogle Scholar
  14. 14.
    Du N, Zhao C-y, Chen Q, Wu G, Lu R (2010) Preparation and characterization of nylon 6/graphite composite. Mater Chem Phys 120:167–171CrossRefGoogle Scholar
  15. 15.
    O’Neill A, Bakirtzis D, Dixon D (2014) Polyamide 6/Graphene composites: The effect of in situ polymerisation on the structure and properties of graphene oxide and reduced graphene oxide. Eur Polym J 59:353–362CrossRefGoogle Scholar
  16. 16.
    Bouhfid R, Arrakhiz FZ, Qaiss A (2016) Effect of graphene nanosheets on the mechanical, electrical, and rheological properties of polyamide 6/acrylonitrile-butadiene-styrene blends. Polym Compos 37:998–1006CrossRefGoogle Scholar
  17. 17.
    Steurer P, Wissert R, Thomann R, Mülhaupt R (2009) Functionalized Graphenes and Thermoplastic Nanocomposites Based upon Expanded Graphite Oxide. Macromol Rapid Commun 30:316–327CrossRefGoogle Scholar
  18. 18.
    Lv Q, Wu D, Qiu Y, Chen J, Yao X, Ding K, Wei N (2015) Crystallization of Poly(ϵ-caprolactone) composites with graphite nanoplatelets: Relations between nucleation and platelet thickness. Thermochim Acta 612:25–33CrossRefGoogle Scholar
  19. 19.
    Xiang M, Li C, Ye L (2018) Reactive melt processing of polyamide 6/reduced graphene oxide nano-composites and its electrically conductive behavior. J Ind Eng Chem 62:84–95CrossRefGoogle Scholar
  20. 20.
    Carella JM, Graessley WW, Fetters LJ (1984) Effects of chain microstructure on the viscoelastic properties of linear polymer melts: polybutadienes and hydrogenated polybutadienes. Macromolecules 17:2775–2786CrossRefGoogle Scholar
  21. 21.
    Katoh Y, Okamoto M (2009) Crystallization controlled by layered silicates in nylon 6–clay nano-composite. Polymer 50:4718–4726CrossRefGoogle Scholar
  22. 22.
    Guan L-Z, Wan Y-J, Gong L-X, Yan D, Tang L-C, Wu L-B, Jiang J-X, Lai G-Q (2014) Toward effective and tunable interphases in graphene oxide/epoxy composites by grafting different chain lengths of polyetheramine onto graphene oxide. J Mater Chem A 2:15058CrossRefGoogle Scholar
  23. 23.
    Tang G, Jiang Z-G, Li X, Zhang H-B, Hong S, Yu Z-Z (2014) Electrically conductive rubbery epoxy/diamine-functionalized graphene nanocomposites with improved mechanical properties. Compos Part B 67:564–570CrossRefGoogle Scholar
  24. 24.
    Lux F (1993) Models proposed to explain the electrical conductivity of mixtures made of conductive and insulating materials. J Mater Sci 28:285–301CrossRefGoogle Scholar
  25. 25.
    Lorenzo A, Müller A (2008) Estimation of the nucleation and crystal growth contributions to the overall crystallization energy barrier. J Polym Sci B Polym Phys 46:1478–1487CrossRefGoogle Scholar
  26. 26.
    Sabino M, Feijoo J, Muller A (2000) Crystallisation and morphology of poly(p-dioxanone). Macromol Chem Phys 201:2687–2698CrossRefGoogle Scholar
  27. 27.
    Müller AJ, Albuerne J, Marquez L, Raquez J-M, Degée P, Dubois P, Hobbs J, Hamley IW (2005) Self-nucleation and crystallization kinetics of double crystalline poly(p-dioxanone)-b-poly(ε-caprolactone) diblock copolymers. Faraday Discuss 128:231–252CrossRefGoogle Scholar
  28. 28.
    Gurland J (1966). Trans Met Soc AIME 236:642Google Scholar
  29. 29.
    J. D. Hoffman, G. T. Davis, and J. I. Lauritzen Jr (1976) In "Treatise on solid state chemistry", pp. 497, SpringerGoogle Scholar
  30. 30.
    Bo Y, Zhaoyi H, Lu L, Xingyue S, Zengheng H (2018). J Polym Res 26(9)Google Scholar
  31. 31.
    Xu J-Z, Liang Y-Y, Huang H-D, Zhong G-J, Lei J, Chen C, Li Z-M (2012) Isothermal and nonisothermal crystallization of isotactic polypropylene/graphene oxide nanosheet nanocomposites. J Polym Res 19:9975CrossRefGoogle Scholar
  32. 32.
    Kim CI, Oh SM, Oh KM, Gansukh E, Lee H-i, Jeong HM (2014) Graphenes for low percolation threshold in electroconductive nylon 6 composites. Polym Int 63:1003–1010CrossRefGoogle Scholar
  33. 33.
    Ramesh C, Gowd EB (2001) High-Temperature X-ray Diffraction Studies on the Crystalline Transitions in the α- and γ-Forms of Nylon-6. Macromolecules 34:3308–3313CrossRefGoogle Scholar
  34. 34.
    Wu C-M, Cheong S-S, Chang T-H (2016) Rheological properties of graphene/nylon 6 nanocomposites prepared by masterbatch melt mixing. J Polym Res 23:242CrossRefGoogle Scholar
  35. 35.
    Filippone G, Netti P, Acierno D (2007) Microstructural evolutions of LDPE/PA6 blends by rheological and rheo-optical analyses: Influence of flow and compatibilizer on break-up and coalescence processes. Polymer 48:564–573CrossRefGoogle Scholar
  36. 36.
    He Z, Zhang B, Zhang H-B, Zhi X, Hu Q, Gui C-X, Yu Z-Z (2014) Improved rheological and electrical properties of graphene/polystyrene nanocomposites modified with styrene maleic anhydride copolymer. Compos Sci Technol 102:176–182CrossRefGoogle Scholar
  37. 37.
    Wu D, Wu L, Sun Y, Zhang M (2007) Rheological properties and crystallization behavior of multi-walled carbon nanotube/poly(ɛ-caprolactone) composites. J Polym Sci B Polym Phys 45:3137–3147CrossRefGoogle Scholar
  38. 38.
    Wu D, Lv Q, Feng S, Chen J, Chen Y, Qiu Y, Yao X (2015) Polylactide composite foams containing carbon nanotubes and carbon black: Synergistic effect of filler on electrical conductivity. Carbon 95:380–387CrossRefGoogle Scholar
  39. 39.
    Ding K, Wei N, Zhou Y, Wang Y, Wu D, Liu H, Yu H, Zhou C, Chen J, Chen C (2016) Viscoelastic behavior and model simulations of poly(butylene adipate-co-terephthalate) biocomposites with carbon nanotubes: Hierarchical structures and relaxation. J Compos Mater 50:1805–1816CrossRefGoogle Scholar
  40. 40.
    Wang Y, Cheng Y, Chen J, Wu D, Qiu Y, Yao X, Zhou Y, Chen C (2015) Percolation networks and transient rheology of polylactide composites containing graphite nanosheets with various thicknesses. Polymer 67:216–226CrossRefGoogle Scholar
  41. 41.
    Sarman S, Laaksonen A (2009) Evaluation of the viscosities of a liquid crystal model system by shear flow simulation. Chem Phys Lett 479:47–51CrossRefGoogle Scholar
  42. 42.
    J. D. Ferry (1980) "Viscoelastic properties of polymers", John Wiley & SonsGoogle Scholar
  43. 43.
    Y.-H. Lin (2011) "Polymer viscoelasticity: basics, molecular theories, experiments and simulations", World ScientificGoogle Scholar
  44. 44.
    Doi M, Edwards S (1978). J Chem Soc Faraday Trans 74:1818CrossRefGoogle Scholar
  45. 45.
    Mayoral B, Harkin-Jones E, Khanam P, AlMaadeed M, Ouederni M, Hamilton A, Sun D (2015) Melt processing and characterisation of polyamide 6/graphene nanoplatelet composites. RSC Adv 5:52395–52409CrossRefGoogle Scholar
  46. 46.
    Zang CG, Zhu XD, Jiao QJ (2015) Enhanced mechanical and electrical properties of nylon-6 composite by using carbon fiber/graphene multiscale structure as additive. J Appl Polym Sci 132CrossRefGoogle Scholar

Copyright information

© The Polymer Society, Taipei 2019

Authors and Affiliations

  1. 1.Department of Materials EngineeringJiangsu University of TechnologyChangzhouChina
  2. 2.State Key Laboratory of Polymer Materials EngineeringPolymer Research Institute of Sichuan UniversityChengduChina

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