INTERACTION OF POLY (METHYL-METHACRYLATE) AND NAFIONS

The thermal degradation of Nafion-H, Nafion-K, and the mixture of each of these with poly(methyl methacrylate) (PMMA) has been studied. A mechanism is proposed for the thermal degradation of Nafion-H that involves an initial cleavage of the carbon-sulfur bond leading to SO2 an OH radical and a carbon-based radical. This carbon-based radical then undergoes further degradation. The addition of PMMA to Nafion-H inhibits further degradation of the Nafion carbon-based radical and instead radical recombination reactions between PMMA fragments and this Nafion radical dominate the reaction scheme. The replacement of the hydrogen in Nafion-H with a potassium (i.e., Nafion-K) produces a much more robust material that does not degrade under conditions similar to those used for Nafion-H. Nafion-K has little effect on the degradation of PMMA.