Measurements of Nitrogen Tetroxide Solubility and Diffusion Rate in Teflon

Nitrogen Tetroxide (N2O4) is a known plasticizer of polymers. In the current study, Teflon samples were exposed to liquid nitrogen tetroxide at various temperatures. The samples were monitored for both volume change (swelling), mass changes, and changes in Shore D hardness due to uptake of nitrogen tetroxide. The change in diffusion into and out of the material was also measured. After exposure to nitrogen tetroxide, white Teflon samples turned a slight orange color due to nitrogen tetroxide uptake. The mass gained and % swelling of the samples at the saturation limit varied slightly with temperature (range 20 °C to 120 °C). The hardness was also observed to decrease with increased concentration of nitrogen tetroxide dissolved in the Teflon. The diffusion time as a function of temperature of the nitrogen tetroxide migrating into or out of the Teflon samples was measured and agrees well with the one previous measurement in the literature.