Hyperbranched poly(amidoamine)/kaolinite nanocomposites: Structure and charge carrier dynamics

Publication date: 14 July 2017
Source:Polymer, Volume 121
Author(s): Shereen Shabaan Omara, Gamal Turky, Ahmed Ghoneim, Andreas F. Thünemann, Mona H. Abdel Rehim, Andreas Schönhals
An ex-situ approach was applied to prepare nanocomposites from hyperbranched poly(amidoamine) and modified kaolinite (Ka-DCA). The structure of the polymer and the corresponding nanocomposites was investigated by FTIR, DSC, SAXS and TEM. SAXS might suggest a partly exfoliated structure of the nanocomposites, which was supported by TEM. The molecular dynamics was studied by means of broadband dielectric spectroscopy (BDS). The dielectric spectra are dominated by a conductivity contribution at higher temperatures for all samples investigated. The obtained results further indicated that DC conductivity is increased by 4 orders of magnitude with increasing concentration of Ka-DCA nanofiller. Further, a significant separation between the conductivity relaxation time and that of segmental dynamics was observed. The decoupling phenomenon and the conductivity mechanism were discussed in detail. This study provides insights about the influence of the nanofiller on the structure and the conductivity contribution of nanocomposites of hyperbranched polymers including the decoupling phenomenon and fragility.

Graphical abstract

http://ift.tt/2szoMhj