GAS-TRANSPORT IN RING-SUBSTITUTED POLYANILINES

The gas transport properties of polymethoxyaniline (PMANi) and polyeth oxyaniline (PEANi), in which the methoxy and ethoxy groups mere introd uced onto the benzene rings at the ortho position, were studied to det ermine the effect of substituents. Measurements were carried out at 40 psi from 25 degrees C to 55 degrees C. When compared with polyaniline , the gas permeability increases with the size a substituent because o f the increases in the diffusivities while the selectivities remain th e same or Increase for some gas pairs. Excellent correlations were fou nd between the diffusion coefficients and the molecular diameters of g ases and between the solubility coefficients of gases and their boilin g points (or critical temperatures).