Third Day Poster Session, 17 June 2010 - NanoTR-VI

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Poster Session, Thursday, June 17
Theme F686 - N1123
The Surface Modification of ZnO and its Effect on the Properties of Polymer Nanocomposites
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Hande Celebi,P PGoknur Bayram,P Pand UAydin DoganUP P*
PDepartment of Chemical Engineering, Anadolu University, Eskisehir 26555, Turkey
PDepartment of Chemical Engineering, Middle East Technical University, Ankara 06531, Turkey
PDepartment of Materials Science and Engineering, Anadolu University, Eskisehir 26555, Turkey
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Abstract- Polymer nanocomposites based on thermoplastic poly(ether ester) and zinc oxide (ZnO) were prepared by melt mixing using a microcompounder.
The electrical, thermal and mechanical properties of the nanocomposites with various ZnO concentrations were investigated. The
resulting properties depend on the matrix-filler and filler-filler interactions were detailed as the aim of this study.
In recent years polymer nanocomposites have attracted great
interest and have a wide potential application in diverse areas
[1]. They combine the properties of inorganic materials and
polymers in a unique structure such as ease of processing,
chemical stability of polymers and high modulus and electrical
behavior of inorganic fillers [2]. Some of the properties of
these materials differ from both the polymer matrix and
inorganic nanoparticles.
Thermoplastic elastomers are a new and important class of
engineering polymers, with the properties of vulcanized
rubbers and processability typical of thermoplastic elastomers
[3]. These materials combine good low temperature flexibility
with an excellent mechanical and thermooxidative stability up
to high temperatures and a good resistance against many
chemicals [4].
ZnO has received broad attention in materials research due
to its versatile properties, ease of preparation and low cost [5].
Because of its prominent properties, it can be potentially used
as catalysts, gas sensors, semiconductors, varistors,
piezoelectric devices, UV shielding materials and antibacterial
agents [2].
The objective of this study was to prepare and characterize
multiblock thermoplastic poly(ether ester) and their
composites. This study consisted of three parts. In the first part
of the study, the copolymers of poly(butylene terephthalate) –
poly(tetramethylene ether) glycol (PBT-PTMEG) were
synthesized by the two stage polycondensation method.
In the second part, zinc oxide (ZnO) particles were
synthesized by homogeneous precipitation method. This wet
chemical route for the synthesis of nanostructures is a valuable
alternative to conventional processing methods. Water-based
chemical methods offer numerous advantages like being
environmentally benign, using cheap and easy handle starting
products and low cost, uncomplicated equipment, while
requiring only a new energy input [5]. The synthesized
particles, which were approximately 300 nm in dimension
(Figure 1) were modified with polyvinylpyrrolidone (PVP) to
improve the compatibility between the polymer matrix. The
particles were investigated by HFourier Transform Infrared
SpectroscopyH (FTIR), Scanning Electron Microscopy (SEM)
and TX-Ray Diffraction (TXRD) analysis. The mass of adsorbed
PVP on the particle surface was measured as 80 % by
thermogravimetric analysis.
Figure 1. SEM micrograph of synthesized ZnO particles
In the last part of the study, composites were prepared by
introducing the fillers into the copolymers by using a melt
compounder. The influence of ZnO modification and
concentration on the properties of the nanocomposites was
studied by SEM, mechanical, thermal and electrical analysis.
SEM investigations showed homogeneous dispersion of the
fillers in the matrix. The mechanical properties were
determined by tensile tests. The tensile strength of the
nanocomposites decreased with increasing ZnO content. On
the other hand, the elastic modulus values of the composites
increased with the incorporation of ZnO particles. There was a
sharp decrease in elongation at break values with increasing
filler content. It was found that addition of ZnO increased
thermal stability, while it decreased coefficient of thermal
expansion of the composites at low temperatures. The
interaction of the polymer-matrix was improved by
modification of ZnO particles with PVP. Its effect was seen on
the mechanical properties of composites. However composites
included modified ZnO as fillers had lower thermal
conductivity values than the composites with unmodified
ZnO. The electrical resistivity of composites remained
constant until 15 wt % ZnO concentration and then started to
decrease by 3-4 orders of magnitude. There was not a great
difference in electrical resistivity values of the
polymer/unmodified ZnO composites when compared to
polymer/modified ZnO composites. The results showed that
ZnO filled elastomers could be used as thermal interface
materials and as antistatic materials.
*Corresponding author: adogan@anadolu.edu.tr
[1] E. Tang, G. Cheng, X. Ma, Powder Technology, 161, 209 (2006).
[2] S.C. Tjong, G. D. Liang, Materials Chemistry and Physics, 100, 1
(2005).
[3] Z. Roslaniec and D. Pietkiewicz, in Handbook of Thermoplastic
Polyesters, edited by S. Fakirov (Wiley, Weinheim, 2002), p. 581
[4] W. Gabrielse, M. Soliman, K. Dijkstra, Macromolecules, 34,
1685 (2001).
[5] H. V. Rul, D. Mondelaers, M. K. Bael, J. Mullens, J. Sol-Gel Sci
Techn, 39, 41 (2006).
6th Nanoscience and Nanotechnology Conference, zmir, 2010 742