Nanotechnology

Studies from National Technical University reveal new findings on polymer research

  2008 NOV 24 - (VerticalNews.com) -- According to a study from Athens, Greece, "In this work, yielding and post yielding effects are analyzed using the idea of the inhomogeneous distribution of strain in polymers under deformation. This idea is directly connected with the free volume concept, as created in the polymeric bulk during the frozen in process, and or the density fluctuations combined with other type defects."

  "A simple strain density distribution function is assumed, following experimental results available from techniques such as positron annihilation lifetime spectroscopy (PALS). Hereafter, a functional form of the rate of plastic deformation is extracted, which will be combined with a given kinematic formulation. The proposed analysis is tested with experimental data of polystyrene (PS) and PS/SiO2 nanocomposites. The incorporation of nanosized fillers into the polymeric bulk, strongly affects the free volume distribution and/or the distribution of defects related with density fluctuations. This fact is reflected in the model parameter values, and their variation in respect to the different material types," wrote G. Spathis and colleagues, National Technical University.

  The researchers concluded: "With the proposed analysis, it has been proved that all features of yield process, including strain softening and strain hardening effect are easily described."

  Spathis and colleagues published their study in Polymer (Strain inhomogeneity effect on yielding of polymer nanocomposites. Polymer, 2008;49(20):4462-4468).

  For more information, contact E. Kontou, National Technical University of Athens, Sect Mech, School Applied Math & Physics Science, 5 Heroes Polytechn, GR-15773 Athens, Greece.

  Publisher contact information for the journal Polymer is: Elsevier Science Ltd., the Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, Oxon, England.

  Keywords: Emerging Technologies, Nanocomposite, Nanosize, Nanotech, NanotechnologyPolymer Research, National Technical University.

  This article was prepared by VerticalNews Nanotechnology editors from staff and other reports. Copyright 2008, VerticalNews Nanotechnology via VerticalNews.com.