Mechanism of electron curing of perfluoropolyethers

Perfluoropolyethers (PFPE's) are a group of polymers widely used as lubricants, dielectric fluids and mechanical and diffusion pump oils. In this paper we show that perfluoropolyethers can be crosslinked with low energy electrons of energy below 14 eV. In fact decomposition of the PFPE's occurs into negative ions and radicals with all electron energies used (1 - 20 eV). The crosslinking is initiated by a dissociative electron attachment process in which the PFPE molecule dissociates into negative ion and a radical The radical left behind then propagates and terminates to form a crosslinked polymer.