Volumen II - SAM

4. CONCLUSSIONS
Through this work the benefits of applying microscopy techniques in failure analysis of polymer composites
is exemplified. HMW-HDPE/MoS2 composites were investigated and morphology-structure-failure
mechanisms-property relations were established.
Optical microscopy and SEM are the techniques usually employed to evaluate the structure and morphology
of composite materials. However, our results demonstrate that the combination of TOM, normal SEM, BEI
and elemental mapping provides identification of the chemical composition and distribution of elements
within polymers that is quite useful for failure analysis. Cracks are well seen by optical microscopy, and
SEM is the better choice to study fracture surfaces. Combination of the various microscopy techniques
provides the best insight into the morphology of polymer composites.
It must be remembered that microscopy techniques provide important information about the structure of
polymers, often necessary to develop structure-property relations, but it is rarely sufficient. We also used
thermal analysis and measurements of coefficient of friction to fully understand material’s behavior.
In this work, microscopy analysis aided to clarify that wear and fracture failure strongly depends on
composites’ microstructure and morphology.
ACKNOWLEDGEMENTS
Authors would like to thank the financial support from CONICET, Universidad Nacional de Mar del Plata,
and Agencia Nacional de Promoción Científica y Tecnológica from Argentina.
REFERENCES
1. L.C. Sawyer and D.T. Grubb, “Polymer Microscopy”, 1996, Chapman & Hall
2. K. Friedrich, “Friction and Wear of Polymer Composites”, 1986, Elsevier Science
3. J.C. Anderson, “High density and ultra-high molecular weight polyethenes: their wear properties and
bearing applications”, Tribology International, 15 (1982) 43-47
4. S. Bahadur, D. Gong, “The action of fillers in the modification of the tribological behavior of
polymers”, Wear, 158 (1992) 41-58
5. M.J. Churruca, “Propiedades mecánicas de compuestos de polietileno de alto peso molecular
modificado con bisulfuro de molibdeno”, Engineering Thesis, University of Mar del Plata, 2007
6. E. Rabinowicz, “Friction and wear of materials”, 1995, John Wiley & Sons
7. G. E. Hale and F. Ramsteiner, “A testing protocol for conducting J-Crack growth resistance curve tests
on plastics”, in: C.R Moore, A. Pavan and J.G. Williams (eds) Fracture Mechanics Testing Methods for
Polymers, Adhesives and Composites, ESIS Publication 28, Elsevier (2001) pp. 123-157
8. H. Unal and A. Mimaroglu, “Friction and wear behaviour of unfilled engineering thermoplastics”,
Materials and Design, 24 (2003) 183-187
9. B.J. Briscoe, “Wear of polymers: an essay on fundamental aspects”, Tribology International, 14 (1984)
231-243
10. S. Bahadur and C. Sunkara, “Effect of transfer film structure, composition and bonding on the
tribological behavior of polyphenylene sulfide filled with nano particles of TiO2, ZnO, CuO and SiC”,
Wear, 258 (2005) 1411–1421
11. V.A. Belyi, A.I. Sviridyonok, V.A. Smurugov and V.V. Nevzorav, “Adhesive wear of polymers”, in:
W.A. Glaeser, K.C. Ludema, S.K. Rhee (Eds.), Wear of Materials, ASME (1977) pp. 526–541
12. Z Jiang, LA Gyurova, AK Schlarb, K Friedrich and Z Zhang, “Study on friction and wear behavior of
polyphenylene sulfide composites reinforced by short carbon fibers and sub-micro TiO2 particles”,
Composites Science and Technology, 68 (2008) 734–742
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