ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
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 angströms. 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.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1988.070350215
Permalink