POLY(ETHER IMIDE)S WITH HINDERING SUBSTITUENTS IN THE ANHYDRIDE MOIETY - SYNTHESIS, PROPERTIES AND GAS PERMEABILITIES

The synthesis of a series of bis(ether anhydride)s with hindering subs tituents, especially t-butyl and methyl, has been developed using nucl eophilic displacement reactions between nitrophthalodinitriles and sub stituted hydroquinones, bisphenols and a naphthalene diol. The bis(eth er anhydride)s have been successfully incorporated into poly(ether imi de)s with hindering residues by polymerization with diamines, with and without alkyl substituents. The thermal and mechanical properties of a number of the polymers and their permeabilities to several gases hav e been determined. The properties of the polymers are discussed, along with those of related polymers. It is shown that the properties are s trongly controlled by their structural features. In particular, the fl exibilities of polymer backbones and substituents are found to influen ce glass transition temperatures and, in conjunction with the influenc e of chain rigidity on packing, to influence gas permeabilities and pe rmselectivities.