Interaction of poly(methyl methacrylate) and nafions

Abstract

SYNOPSISThe 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.

An Overview of Mode of Action and Analytical Methods for Evaluation of Gas Phase Activities of Flame Retardants

“…Proposed pathways for stabilization of tertiary radical of poly(methyl methacrylate) (PMMA) by metal halides or stabilizing radicals [58,60,61].…”

“…To increase the thermal stability of a polymer, additives either prevent the initial decomposition of the polymer or react with the first decomposition products and quench the reaction sequence. The impact of the introduction of a metal chloride or Nafion-H in the PMMA matrix has been studied [58,61]. During the polymer decomposition, small flammable and reactive fragments are formed.…”

Hybridization of Nafion membranes by the infusion of functionalized siloxane precursors

“…In the thermogram of the unmodified Nafion there are two thermal activated degradation processes. The first at around 320°C is due to the decomposition of sulfonic acid groups, while the second one at around 500°C is related to the decomposition of the CF 2 backbone of the Nafion polymer [25]. For the case of the hybrids there is a change in the decomposition temperatures relative to the unmodified Nafion.…”

A review of polymer electrolyte membrane fuel cell durability test protocols

“…Numerous experiments have tackled membrane degradation [82][83][84][85][86][87][88], examining various stressors: temperature, humidity, freeze-thaw cycling, OCV, and Fenton's test. Some examples of membrane ASTs, as well as their testing protocols, are listed in Table 7.…”