STRUCTURE PERMEABILITY RELATIONSHIPS OF POLYAMIDE-IMIDES

Structure/permeability correlations for a family of aromatic polyamide -imides are presented. The variations in chemical structure lead to si gnificant changes in permeability. The crystallization of PAP results in a very low permeability. The introduction of bulky group tends to i ncrease permeability without a corresponding decrease in permselectivi ty. This result contributes to the inhibition of chain packing and seg mental mobility. Wide-angle X-ray diffraction measurements of average segmental spacing of the materials and fractional free volume calculat ions characterize the packing of the different polymers. (C) 1994 John Wiley and Sons, Inc.