EFFECTS OF ELECTRON-BEAM ON THE STRUCTURAL MODIFICATION OF THE CO-POLYMERIC AND THE TERPOLYMERIC FLUOROCARBON RUBBERS

Electron beam initiated modification of the copolymeric and the terpol ymeric fluorocarbon rubbers has been carried out in absence and presen ce of trimethylolpropane triacrylate (TMPTA). ATR-IR studies show abso rption bands at 1710 cm(-1) due to [GRAPHICS] and 1632 cm(-1) due to d ouble bonds, indicating aerial oxidation and dehydrofluorination, resp ectively. The later is also measured from the C-F absorbances at 1397, 1021 and 672 cm(-1). XPS studies are in line with the IR-observations . Comparative study of the copolymer and the terpolymer based systems over a range of radiation doses (50-200 kGy) reveals an increased tend ency towards oxidation and dehydrofluorination of the former. The gel content is also slightly lower. The amount of oxidation is reduced wit h the incorporation of TMPTA at a level of 1 part. Magnesium oxide, wh ich is generally added in fluorocarbon recipe, shows an increased tend ency towards dehydrofluorination at a particular radiation dose (50 kG y). (C) 1998 Elsevier Science Ltd. All rights reserved.