Localizing graphene at the interface of cocontinuous polymer blends: Morphology, rheology, and conductivity of cocontinuous conductive polymer composites

Lian Bai, Siyao He, John W. Fruehwirth, Andreas Stein, Christopher W. Macosko, Xiang Cheng

Research output: Contribution to journalArticlepeer-review

65 Scopus citations

Abstract

Interfacial localization of graphene in cocontinuous polymer blends is shown to be effective in stabilizing the cocontinuous morphology and increasing conductivity with a low electrical percolation threshold. We created polylactic acid (PLA) and polystyrene (PS) cocontinuous blends filled with thermally reduced graphene oxide (r-GO) localized at the interface. The resulting conductive composites show dramatically improved conductivity at low filler loadings and an ultralow percolation threshold of 0.028 vol. %. We systematically studied the changes of conductivity and rheology of the PLA-PS composites during annealing. We found that r-GO transfers from the PLA phase to the interface during melt compounding and annealing and forms a spanning 3D network, which effectively suppresses the coarsening of the cocontinuous structure. Our study demonstrated that the 3D r-GO network significantly increases the conductivity and the storage modulus of the melt blends. Finally, we constructed a simple model, which quantitatively explains the correlations between structural, electrical, and rheological properties of conductive polymer composites.

Original languageEnglish (US)
Pages (from-to)575-587
Number of pages13
JournalJournal of Rheology
Volume61
Issue number4
DOIs
StatePublished - Jul 1 2017

Bibliographical note

Funding Information:
The project was funded by the Industrial Partnership for Research in Interfacial and Materials Engineering (IPRIME). This work was also supported in part by the Petroleum Research Institute of Abu Dhabi through its Joint Polymer Processing Research Program with the University of Minnesota. Portions of this work were performed in the University of Minnesota, College of Science and Engineering Polymer Characterization Facility, which has received capital equipment funding from the NSF through the UMN MRSEC program under Award No. DMR-1420013. J.W.F. thanks the Undergraduate Research Opportunities Program (UROP) from University of Minnesota.

Publisher Copyright:
© 2017 The Society of Rheology.

Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.

How much support was provided by MRSEC?

  • Shared

Reporting period for MRSEC

  • Period 4

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