ON THE STRUCTURE OF GLASSY POLYMERS. VIII. USE OF Z CONTRAST TO ELUCIDATE THE MICROSTRUCTURE OF EPOXY AND POLYIMID RESINS.

G. V. Di Filippo, J. B. Vander Sande, Donald R Uhlmann

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Abstract

The technique of ultramicrotomy of polymers, followed by staining of the resulting thin sections with heavy metal ions and viewing with Z enhancement in the scanning transmission electron microscope is described. When applied to anhydride-cured epoxy resins, the structure is found to be heterogeneously crosslinked on a scale of a few hundred angstrom. When the technique is applied to amine-cured epoxy resins, the microstructure is found to change from homogeneous to inhomogeneously crosslinked, depending on stoichiometries and cure cycles. For amine-cured resins whose cure conditions are within the range of microstructural change, the bright field of the stained specimens alone does not detect heterogeneities, and the Z contrast becomes crucial to discern the kind of microstructure. A commercial polyimide film examined in the same way is found to exhibit systematic variations in structure through the thickness of the film.

Original languageEnglish (US)
Pages (from-to)485-505
Number of pages21
JournalJournal of Applied Polymer Science
Volume35
Issue number2
Publication statusPublished - Feb 5 1988

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ASJC Scopus subject areas

  • Polymers and Plastics

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