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

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Poster Session, Thursday, June 17
Theme F686 - N1123
Evaluation of Permeability of Masterbatch-Based PA6/nanoclay Composite Films
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UMohammad FasihiUP0F P*and Mohammad Reza Abolghasemi0TP
Technology of Polymer Research Group, Iranian Academic Center for Education, Culture and Research (ACECR), Branch of Amirkabir
University of Technology, Tehran, Iran,
Abstract-This study focuses on the effect of the nanoclay masterbatch on the extent of exfoliation and barrier properties of PA6/organoclay
nanocomposite films. Gas permeability through nanocomposite films decreased significantly just by loading a small amount of nanoclay.
Theoretical models fit the experimental data appropriately.
Over the last decades, a great deal of researches have been
devoted to the different fields of polymer-layered silicate
nanocomposites which have shown promising improvements
[1-3]
in properties, at low filler volume fraction.P
One of the great attractive applications of polymer-layered
silicate nanocomposites is the field of packaging. The
reduction of oxygen permeability is of crucial importance
since oxygen as an atmospheric component which promotes
the spoilage mechanism of food. Incorporating layered silicate
into the polymeric matrix, ordinarily, improves gas barrier
properties of the polymer by reducing the volume available for
gas transport as well as making a more tortuous path for
[4-6]
penetrant molecules. P
The current study examined the effect of nanoclay
dispersion by using particulate nanoclay and nanoclay
masterbatch, on morphology and oxygen permeability of
polyamide-6 /layered silicate nanocomposite films bearing
different concentrations of nanoclay, as a potential candidate
for good packaging applications. Furthermore, the
permeability data has also been compared to the theoretical
models.
XRD results showed flat diffraction profile and the absence
of any basal reflections indicated that the ordered layers of
nanoclays in the nanocomposites have been disrupted.
With regards to the crystalline structure, all films exhibited a
o
strong reflection at 21.5P distinguished t
crystal form which showed that the loading of nanoclay did
not alter crystal structures in thin films.
Although XRD scan results suggested only a low degree of
intercalation, the morphology observed with TEM indicated
the presence of both intercalated and exfoliated structures. The
general impression obtained from TEM was that the use of
masterbatch builds up a higher degree of exfoliation that
confirms the better properties of masterbatch-based
nanocomposites. The maximum aspect ratio of the layers as
deduced from the TEM micrographs was about 210 in all
samples.
Oxygen permeability was reduced by a factor of 4 over the
pure polyamide by incorporation of 3 wt% nanoclay. As the
nanoclay loading was increased to 7 wt%, only a slight
improvement in permeation resistance was observed.
Several studies on modeling the barrier properties of
polymer nanocomposite have been performed based on the
[7],
tortuous pathway concept by Cussler.P Fredrickson and
[8,9]
Gusev et al.P Bharadwaj improved Nielsen’s model by
[6]
simply introducing a new order parameter. P Another model
[10]
called NG model was developed by Ghasemi et al.P
PThe
theoretical models fit the experimental data properly.
In summery, we showed improvements in oxygen barrier
and mechanical properties by increasing the silicate content. In
particular, nanocomposite films based on masterbatch
exhibited the best performances. XRD scans and TEM
micrographs collectively demonstrated the good dispersion
and orientation of silicate platelets inside the matrix, as well as
the possible presence of polymer-clay interactions. The
theoretical model fitted the experimental data very well.
Figure 1. TEM images of specimens (a) particulate nanoclay-based
films (b), (c) masterbatched-based films
*Corresponding author:
mohammadreza.abolghasemi@gmail.com
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[7] Yang, W.H. Smyrl, E.L. Cussler, J. Membr. Sci. 2004, 231,
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[9] A.Gusev, H.R. Lusti, Adv. Mat., 2001, 13, 1641-1643.
[10] E. Ghasemi, A. H. Navarchian, “Modeling the Effects of
Silicate Layer Orientation on Barrier Properties of Polymer/Clay
Nanocomposites”, proceeding of 9th International Seminar on
Polymer Science and Technology (3TISPST3T 2009), Tehran, Iran.
6th Nanoscience and Nanotechnology Conference, zmir, 2010 714