Journal of Materials Science

, Volume 53, Issue 9, pp 6519–6541 | Cite as

Effect of surface functionalization of halloysite nanotubes on synthesis and thermal properties of poly(ε-caprolactone)

  • Zoi Terzopoulou
  • Dimitrios G. Papageorgiou
  • George Z. Papageorgiou
  • Dimitrios N. Bikiaris


In this work, halloysite nanotubes (HNTs) and functionalized HNTs–APTES (aminopropyltriethoxysilane) in concentrations 0.5, 1 and 2.5 wt% were used as nanofillers in the synthesis of poly(ε-caprolactone) (PCL) nanocomposites via the in situ ring-opening polymerization of ε-caprolactone (CL). The successful functionalization of HNTs was confirmed with X-ray photoelectron spectroscopy. The effects of HNTs and HNTs–APTES on the polymerization procedure and on the thermal properties of PCL were studied in detail. It was found that both nanofillers reduced the \( \bar{M} \)n values of the resulting nanocomposites, with the unfunctionalized one reducing it in a higher extent, while SEM micrographs indicated satisfactory dispersion in the PCL matrix. The crystallization study under isothermal and dynamic conditions revealed the nucleating effect of the nanotubes. The functionalization of nanotubes enabled even faster rates and attributed higher nucleation activity as a result of better dispersion and the formation of a strong interface between the filler and the matrix. An in-depth kinetic analysis was performed based on the data from crystallization procedures. PLOM images confirmed the effectiveness of both fillers as heterogeneous nucleation agents. Finally, from TGA analysis, it was found that HNTs did not affect the thermal stability of PCL while for HNTs–APTES, a small decrease in Tmax was observed, of about 5 °C for all filler contents.



The authors would like to thank Associate Professor Konstantinos Triantafyllidis of the Laboratory of Chemical and Environmental Technology, Department of Chemistry, Aristotle University of Thessaloniki, for the nitrogen adsorption/desorption experiments.

Compliance with ethical standards

Conflict of interest

The authors declare no conflict of interest.

Supplementary material

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Supplementary material 1 (DOCX 3123 kb)


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Authors and Affiliations

  1. 1.Laboratory of Polymer Chemistry and Technology, Department of ChemistryAristotle University of ThessalonikiThessalonikiGreece
  2. 2.School of Materials and National Graphene InstituteUniversity of ManchesterManchesterUK
  3. 3.Department of ChemistryUniversity of IoanninaIoanninaGreece

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