Degradation processes in fluorinated polymers for space applications

PMSE 344

Mircea Chipara, Indiana University Cyclotron Facility, Indiana University, 2401 Milo B Samson Lane, Bloomington, NE 47408-1398, David Hui, Mechanical Engineering, University of New Orleans, New Orleans, LA, and Magdalena D. Chipara, Institute for Electrotechnical Researches, Bucharest, Romania.
The adverse environment of low space orbits consists of ionizing radiations (protons, electrons, and relatively few energetic ions), atomic oxygen fluxes, UV, and extreme temperatures. Outstanding materials are required withstanding such conditions. Although fluorinated polymers exhibit a good thermal stability, the cocktail of ionizing radiation and oxygen leads to a catastrophic failure. Electron spin resonance investigations on some fluorinated polymers reveal that the impinging radiation triggers the degradation while the oxygen accelerates dramatically the degradation process. The resonance data confirms that the uncoupled electron of primary free radicals is delocalized over fluorine nuclei. Radiation effects of composites based on fluorine and graphite (such as Tedlar) are assessed. It is concluded that the high sensitivity of C-F bond to ionizing radiations, and the rapid oxidation of primary radicals into peroxy radicals is a feature of all fluorinated polymers and should be a serious argument to search for alternative solutions.

Joint PMSE/POLY Poster Session
5:30 PM-7:30 PM, Tuesday, September 9, 2003 Hilton New York -- Rhinelander Center, Poster

8:00 PM-10:00 PM, Monday, September 8, 2003 Javits Convention Center -- North Pavillion, Sci-Mix

Division of Polymeric Materials: Science and Engineering
The 226th ACS National Meeting, New York, NY, September 7-11, 2003