THERMOLYTIC DEGRADATION BEHAVIOR OF INORGANIC ION-EXCHANGER INCORPORATED NAFION-117

A perfluoro-sulphonate-ionomer membrane (Nafion-117), incorporated wit h inorganic ion exchanger (IIE), was evaluated using thermogravimetric analysis and FT-IR spectroscopy to ascertain its thermolytic degradat ion behavior. The two-step decomposition shown by derivative scans in the Nafion-polyantimonic acid composite was studied by obtaining FT-IR spectra of thermally treated specimens under dynamic conditions up to 200 degrees, 350 degrees and 400 degrees C. Similar studies were carr ied out for Nafion-zirconium phosphate and Nafion-zirconium oxide comp osites. Incorporation of IIE invariably decreased the thermal stabilit y of the perfluoro polymer matrix of Nation. However, the decompositio n patterns of -SO3H groups remained unaffected. Comparative studies of the TGA and DTA scans of these composites show presence of water of c rystallization in the incorporated IIEs. (C) 1998 Elsevier Science B.V .