ISOMERIC POLY(ETHER IMIDE)S - SYNTHESIS, THERMAL-PROPERTIES AND PERMEABILITIES

This paper describes the synthesis of a novel series of poly(ether imi de)s formed as isomeric pairs of polymers by interchanging the diol an d diamine derived units. The polymers contained units having flexible and stiff hinges and groups to hinder segmental rotation. Most Polymer s were soluble in a variety of solvents, which allowed them to be char acterized and cast into membranes. Permeabilities to carbon dioxide an d methane and glass transition temperatures were determined. Considera tion of structure-property relations showed the properties of the poly mers to be sensitive to the position of the structural units within th e polymer. The polymers showed a linear relationship between permeabil ities to the two gases. There was a strong trend between high permeabi lity and high glass transition temperature, suggesting that rigid poly mers incapable of inefficient packing lead to highly permeable membran es and that such factors were enhanced by the presence of bulky substi tuents.