Spectroscopic comparison of effects of electron radiation on mechanical properties of two polyimides

Technical Report · Wed Apr 01 00:00:00 EST 1987

OSTI ID:6543192

Long, Jr, E R; Long, S A.T.

The differences in the radiation durabilities of two polyimide materials, Du Pont Kapton and General Electric Ultem, are compared. An explanation of the basic mechanisms which occur during exposure to electron radiation from analyses of infrared (IR) and electron paramagnetic resonance (EPR) spectroscopic data for each material is provided. The molecular model for Kapton was, in part, established from earlier modeling for Ultem (pp. 1293-1298 of IEEE Transactions on Nuclear Science, December 1984). Techniques for understanding the durability of one complex polymer based on the understanding of a different and equally complex polymer are demonstrated. The spectroscopic data showed that the primary radiation-generated change in the tensile properties of Ultem (a large reduction in tensile elongation) was due to crosslinking, which followed the capture by phenyl radicals of hydrogen atoms removed from gem-dimethyl groups. In contrast, the tensile properties of Kapton remained unchanged because radical-radical recombination, a self-mending process, took place.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (USA). Langley Research Center
• OSTI ID: 6543192
• Report Number(s): N-87-18611; NASA-TP-2663; L-16200; NAS-1.60:2663
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
IMIDES
PHYSICAL RADIATION EFFECTS
POLYMERS
COMPARATIVE EVALUATIONS
ELECTRON BEAMS
EXPERIMENTAL DATA
TENSILE PROPERTIES
BEAMS
DATA
INFORMATION
LEPTON BEAMS
MECHANICAL PROPERTIES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
360605* - Materials- Radiation Effects