Filler dispersion and electrical properties of polyamide 12/MWCNT-nanocomposites produced in reactive extrusion via anionic ring-opening polymerization

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Sven Haensch - , Leibniz Institute of Polymer Research Dresden (Author)
  • Robert Socher - , Leibniz Institute of Polymer Research Dresden, TUD Dresden University of Technology (Author)
  • Doris Pospiech - , Leibniz Institute of Polymer Research Dresden (Author)
  • Brigitte Voit - , Chair of Organic Chemistry of Polymers, Leibniz Institute of Polymer Research Dresden (Author)
  • Kathrin Harre - (Author)
  • Petra Poetschke - , Leibniz Institute of Polymer Research Dresden (Author)

Abstract

The reactive extrusion of lauryl lactam to polyamide 12 (PA12) of controlled molar mass was successfully performed in a microcompounder. The maximum residual monomer content was less than 1%. The insitu polymerization in the presence of 1-5 wt.% multiwalled carbon nanotubes (MWCNTs) was studied and the processing conditions were optimized with respect to the electrical resistivity and MWCNT dispersion. Runs which yielded in higher molar mass PA12 resulted in better dispersion of MWCNTs, whereas nanocomposites with lower molar mass PA12 had lower electrical percolation thresholds (MWCNT concentration similar to 1 wt.%). A high screw speed of 200 rpm was identified to cause best dispersion and the lowest percolation threshold.Subsequently, the in-situ polymerized composites were compared with composites obtained by direct melt mixing of PA12 with MWCNTs. In comparison to the composites from commercial PA12 and MWCNTs, the dispersion of primary MWCNT agglomerates via in-situ polymerization is considerably better from which better mechanical properties may be expected. However, better dispersion did not result in a reduced electrical percolation threshold and resistivity. In summary, in-situ polymerization of lauryl lactam under the given conditions was shown to be a suitable processing route to obtain good MWCNT dispersion in PA12. (c) 2012 Elsevier Ltd. All rights reserved.

Details

Original languageEnglish
Pages (from-to)1671-1677
Number of pages7
JournalComposites science and technology
Volume72
Issue number14
Publication statusPublished - 17 Sept 2012
Peer-reviewedYes

External IDs

Scopus 84865586131
ORCID /0000-0002-4531-691X/work/148607867

Keywords

Keywords

  • Carbon nanotubes, Electrical properties, Nano composites, Optical microscopy, Reactive extrusion