1. On the Use of the Nanoindentation Unloading Curve to Measure the Young's Modulus of Polymers on a Nanometer Scale
- Author
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Stefano Piccarolo, Davide Tranchida, TRANCHIDA, and PICCAROLO S
- Subjects
chemistry.chemical_classification ,Materials science ,nanoindentation ,Polymers and Plastics ,business.industry ,polymer ,Organic Chemistry ,Young's modulus ,Polymer ,Nanoindentation ,Amorphous solid ,symbols.namesake ,Contact mechanics ,Optics ,chemistry ,elastic modulu ,Indentation ,Materials Chemistry ,symbols ,mechanical propertie ,atomic force microscopy (AFM) ,Nanometre ,Composite material ,business ,Elastic modulus - Abstract
Summary: The nanoindentation test is a fundamental tool to assess the link between morphology and mechanical properties. The preliminary results of a more exhaustive study about the applicability to polymers of the most used procedure to determine elastic modulus by indentation are reported in this short communication. A departure of the experimental conditions from the theoretical assumptions and results that give rise to the Oliver and Pharr analysis is shown to occur under a wide range of experimental conditions, with applied loads and penetration depths covering several orders of magnitude and using different indenter geometries. Unloading curves with exponents significantly larger than 2 are observed in disagreement with the contact mechanics approach used by Oliver and Pharr. An AFM image obtained in non contact mode of an indentation induced by a sharp AFM tip with a maximum applied load of ca 1.2 µN on amorphous PET.
- Published
- 2005
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