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Hardness

  1. F. J. Baltá Calleja,
  2. A. Flores

Published Online: 15 MAR 2011

DOI: 10.1002/0471440264.pst151.pub2

Encyclopedia Of Polymer Science and Technology

Encyclopedia Of Polymer Science and Technology

How to Cite

Calleja, F. J. B. and Flores, A. 2011. Hardness. Encyclopedia Of Polymer Science and Technology. .

Author Information

  1. Instituto de Estructura de la Materia, CSIC, Madrid, Spain

Publication History

  1. Published Online: 15 MAR 2011

Abstract

A description of the hardness technique and its application to polymer systems is presented. The method is based on the local deformation produced on a material surface by an indenter upon application of a given load. Conventional methods based on the optical measure of the residual impression left behind upon load release represent a rather simple technique for a rapid evaluation of the surface mechanical properties. In the past two decades, depth-sensing indentation devices based on the monitoring of the load and displacement throughout an indentation have progressively substituted traditional testers. Smaller loads can be applied capable of producing penetration depths in the nanoscale. Indentation hardness has nowadays gained widespread application in polymer science. Besides its aforementioned technical advantages, one has to add its extreme sensitivity to detect nanostructural changes occurring in polymer materials. Behind this ability is the intimate correlation between the mechanisms of local deformation and the polymer basic nanostructural entities. The present contribution intends to provide the reader a general overview of the state of the art of indentation hardness in relation to nanostructure and morphology in glassy and semicrystalline polymers including blends.

Keywords:

  • indentation hardness;
  • depth-sensing;
  • creep;
  • nanostructure;
  • crystallinity;
  • glassy polymers and blends