X-ray diffraction analysis of dense PPO membranes

The results obtained from X-ray diffraction of dense poly (2,6-dimethyl-1,4-phenylene oxide) membranes, prepared from different casting solvents, show that the physical properties of solvents have a significant effect on the conformation of the membrane. The diffraction intensities obtained by X-ray analysis are correlated with the selectivity (CO2/CH4) and the permeability of CO2 already reported for these membranes [1]. In view of the results of this study, it seems that when crystallization is low, the state of the amorphous polymer may have an equally important role in the permeability of membranes for gas separation. It was observed that the membranes prepared by trichloro-ethylene and chloroform solvents have similar X-ray diffraction patterns and are of homogeneous morphology. The peak widths suggest small crystallites on the average, thus evenly dispersed in the membrane. (C) 2000 Elsevier Science B.V. All rights reserved.