P 34 ISSRNS 2012: Abstracts / Synchrotron Radiation in Natural Science Vol. 11, No 1 – 2 (2012)
CRYSTALLISATION OF POLYMER PHASES AND ITS INFLUENCE ON STRUCTURE AND MECHANICAL PROPERTIES
OF MULTILAYERED POLYMER SYSTEMS
M. Ma lachowski1 and M. Kozak2∗
1Technological Departament, Podanfol S.A
2Department of Macromolecular Physics, A. Mickiewicz University, Pozna´n, Poland Keywords: multilayered packing materials, polymer crystallisation, polyamide, polyethylene
∗e-mail : mkozak@amu.edu.pl
Thanks to their numerous advantageous features multilayered polymer systems have found a wide range of applications, in particular in food indus- try. Their structural and mechanical stability can be controlled by proper choice of parameters of their production [1]-[3].
The aim of the study was to check the influ- ence of cooling process of a polymer melts on the structure of the crystalline phase and mechanical properties of the multilayered structures.
The materials studied were obtained by co- extrusion of low density polyethylene (LDPE) and polyamide 6 (PA6). The process of production could be divided into four stages: extrusion, cooling, ori- entation and structural stabilisation.
In the process the cooling medium was in direct contact only with the external polymer layer, while the other layers were isolated. The subsequent stage is mechanical orientation of the structure, which is sensitive and difficult as the structure improperly prepared can prove too flexible or too brittle and susceptible to cracking.
The crystalline structure of the polymer sam- ples was studied by the wide angle X-ray diffraction
method (WAXS). Morphology of particular poly- mer layers was investigated under a scanning elec- tron microscope (SEM). Mechanical properties of the samples were examined in a series of tests.
The samples studied were three and four-layer structures PA6 / LDPE / PA6 and PA6 / LDPE / PA6 / LDPE. No binding polymers were used so that the layers could be easily sepa- rated and each layer could be studied separately.
Results provided by WAXS method permit- ted the observations of changes in the crystallinity degree in particular polymers and verification of changes in the crystal phase structure.
References
[1] H. Shanak, K.H. Ehses, W. Gotz, P. Leibenguth, R.
Pelster, J. Mater. Sci. 44 (2009) 655 – 663.
[2] T.D. Fornes, D.R. Paul, Polymer 44 (2003) 3945 – 3961.
[3] N. Vasanthan, J. Polym. Sci. B: Pol. Phys. 41 (2003) 2870 – 2877.
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