Image icon  Spherulites in poly-3-hydroxy butyrate (PHB)

 
Use this resource: Use this resource icon
Link to this page: http://core.materials.ac.uk/search/detail.php?id=1634
View at:            
Resource type: Image
Description: Polymer melts often crystallise from heterogeneous nuclei to form ribbon-like lamellae, which have a folded chain molecular structure. They commonly radiate outwards from the nucleation point, to form spherical features called spherulites - which are often quite large. The characteristic Maltese cross pattern, seen when viewed between crossed polars, results from isoclinic fringes formed when one of the principal vibration directions is approximately parallel to the polariser. In some cases (including the Poly-3-hydroxy butyrate (PHB) viewed here), the lamella twist as they grow outwards, in phase with their neighbours. This gives rise to the observed ring pattern. When viewed with a full wave plate, alternate (fast and slow) rings are coloured blue and yellow.
Keywords: alignment • crystal • polyhedral • polyhydroxybutyrate (PHB) • polymer • spherulite
Categories: Science approaches > Microstructure
Materials > Polymers & elastomers > Plastics > Thermoplastics
Testing, analysis & experimentation > Metallography
Scale > Micro
Created by: DoITPoMS, University of Cambridge
Prof T W Clyne, Department of Materials Science and Metallurgy, University of Cambridge
Published by: DoITPoMS, University of Cambridge
License: This resource is released under the Creative Commons Attribution Non-Commercial Share Alike license (2.0 UK: England & Wales).
Creative Commons Attribution Non-Commercial Share Alike logo
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).
  • noncommercial – You may not use this work for commercial purposes.
  • share alike – If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.
View the full legal code here.
Date created: 03 October 2002
Date added: 21 August 2009
Package:
Resource ID: 1634