REPEAT UNIT STRUCTURE AND GAS-TRANSPORT PROPERTIES OF AROMATIC POLYMERS

Structure/transport-property correlations for a family of aromatic polyesters and polyphenylene oxides are presented. How modification in repeat unit structure changes the packing of bulk polymers, and subsequently the solubility and diffusivity of gases in polymers is addressed in detail. In addition to polymer-gas attraction, polymer packing density is proposed to be an important factor in determining the gas-absorbing capacity of glassy polymers. The observed diffusivity data are strongly correlated with polymer packing. Moreover, scatter in the correlation can be satisfactorily attributed to differences in local chain mobility among the polymers investigated here.