Characterization of Microvoids in Glassy Polymers by Means of 129Xe NMR Spectroscopy

129Xe NMR chemical shift of 129Xe sorbed in glassy polymers has been studied in connection with Xe sorption property. Poly(2,6-dimethyl-1,4-phenylene oxide), polystyrene, Bisphenol A polycarbonate, and tetramethyl-Bisphenol A polycarbonate have been used as glassy polymers. Xe sorption isotherms of glassy polymers have been successfully interpreted by the dual-mode sorption model. 129Xe NMR chemical shifts of 129Xe in glassy polymers have shown non-linear low-field shift against sorption amount of Xe. From the Xe density dependence of the 129Xe NMR chemical shift, it has been able to evaluate mean size of microvoids in glassy polymer. These findings suggest that the 129Xe NMR spectroscopy is a good tool for characterizing microvoids in glassy polymers.