ISSN:
0887-6266
Keywords:
bismaleimide composite
;
thermogravimetry
;
anistropic degradation
;
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The weight loss of carbon fiber-reinforced polymeric composites in air has been found to depend on the sample surface characteristics such as fiber orientation with respect to the exposed surfaces. This phenomenon can be attributed to the diffusion of oxygen through the sample and the dependence of diffusion rate on fiber orientation. Recently, an anisotropic degradation methodolgy was proposed, based on the unreactedcore principle, commonly used in catalysis, as extended to account for the anisotropic effects. In this work, these anisotropic diffusion effects were also identified for small thermogravimetric (TGA) samples. Isothermal TGA experiments were performed in air at 310°C using samples weighing 10-163mg. Weight loss was found to be a strong function of fiber orientation. The anisotropic degradation methodology successfully predicted the weight loss of all samples, although some deviation attributed to the sample edge effects was observed. When samples were examined by optical microscopy, a degraded zone was observed on the sample surfaces. The thickness of this layer depended on the type of exposed surface, validating the anisotropic degradation methodology. © 1993 John Wiley & Sons, Inc.
Additional Material:
13 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/polb.1993.090310812
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