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Journal of Materials Science

, Volume 25, Issue 6, pp 2727–2736 | Cite as

Electron microscopy of non-periodic layer crystallites in thermotropic random copolymers

  • Richard J. Spontak
  • Alan H. Windle
Article

Abstract

Transmission electron microscopy (TEM) has been used to characterize non-periodic layer crystallites in thermotropic random copolyesters composed of 4-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid. The crystallites are most clearly observed when imaged in the equatorial reflection, indicating that they are associated with intermolecular ordering. The crystallites appear to be platelets with their thin axis parallel to the molecular chain axis. Crystallite growth is highly dependent on thermal history and occurs to a significant extent during the early stages of annealing above the glass-transition temperature in the solid state. Long-term annealing of the copolymers results in an increase in the number of crystallites, as well as sharpening the diffraction pattern. The extent of lateral development of the ordered regions also depends on the degree of polymerization (DP), being greater for a copolymer of lower DP.

Keywords

Transmission Electron Microscopy Diffraction Pattern Solid State Thermal History Molecular Chain 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Chapman and Hall Ltd 1990

Authors and Affiliations

  • Richard J. Spontak
    • 1
  • Alan H. Windle
    • 1
  1. 1.Department of Materials Science and MetallurgyUniversity of CambridgeCambridgeUK

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