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D. Salaberger, T. Koch, Y Voronko, S. Seidler, J. Kastner:
"Comparison of particle size distributions derived from 2D and 3D analysis for particle filled polymers";
Talk: Polychar 20, World Forum on Advanced Materials, Dubrovnik; 2012-03-26 - 2012-03-30; in: "Book of Abstracts", (2012), ISBN: 978-953-6470-57-0; 95.

To increase mechanical and physical properties and to reduce costs of polymeric components it is common practice to add fillers. Platelet fillers like talc and mica increase tensile strength, Young´s modulus and electrical conductivity; they decrease thermal expansion and shrinkage and can be used as filler for cost reduction.
For the improvement of mechanical properties the high aspect ratio and the three dimensional distribution and orientation are decisive.
For this study mica filled polypropylene was investigated by 2D sectioning and 3D X-ray tomography (XCT). XCT was performed on a laboratory system. From both methods 3D data sets can be derived whereas direct 3D information is available only from XCT. Serial sectioning is more time consuming and prone to errors at stacking the images to a 3D data set but has the advantage of high resolution which is independent of the field of view.
The main limitation of XCT is the dependency of resolution on the size of the specimen. The particle size distribution of the investigated mica is very broad which leads for XCT to the case, that the small particles could hardly be detected.
By applying algorithms for 3D data analysis it is possible to extract the information of particle size, particle distribution and orientation. A quasi- 3D analysis can be performed using several images from 2D serial sectioning to extract the same information. Statistical approaches are necessary to estimate particle sizes properly.
The accuracy of the 3D data analysis and the comparison of real 3D and quasi- 3D analysis will be discussed in this contribution. The characteristics of both methods will be shown based on materials with varying mica content. Resolution and related size of the specimen that are necessary to detect the smallest particles while ensuring a representative volume of analysis are investigated.

polymer, composites, particle size, tomography