FT-Raman studies of a range of polyimides subjected to high-energy Radiations at room and elevated temperatures

A range of polyimides have been subjected to electron beam radiolysis at different temperatures. These polyimides were chemically designed to suit space applications, being either transparent or having groups which provide oxidation resistance. The structural changes that occur in the polyimides, when subjected to electron beam irradiation doses up to 18.5 MGy and up to temperatures close to their glass transition temperatures, were studied using FT-Raman spectroscopy. The range of polyimides studied included a series of perfluoropolyimides, a silicon-modified polyimide, and Ultem. The changes in the Raman peak intensities of the different groups indicated scission reactions involving the imide rings and ether linkages. (c) 2006 Wiley Periodicals, Inc.