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Having previously demonstrated the possibility of synthesizing high molecular weight poly(ether imide)s with ortho-linked main-chain units from bis(ether anhydride)s derived from catechol or its derivatives, we now provide a preliminary assessment of the properties of the polymers prepared from the catechol bis(ether anhydride) and a variety of diamines. The polymers have low color, are soluble in a variety of solvents, and are thermally stable to temperatures in excess of 470 °C. Glass transition temperatures are comparable with or higher than that of the commercial poly(ether imide) Ultem. Solvent-cast films have high modului and strengths. Extensions to break are relatively low, except for the polymer based on 4,4‘-bis(4-aminophenoxy)biphenyl, which has an extension of 170%. All the polymers can be drawn to produce materials with higher moduli and strengths and, in most cases, higher extensions to break. Thus the polymers can be processed from the melt or from solution.

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Bis(ether anhydride)s with 3- or 4-phthalimide moieties were prepared by reacting 3- or 4-nitrophthalodinitrile, respectively, with several diols and converting the resulting bis(ether dinitrile)s to bis(ether anhydride)s. Selected dianhydrides were converted into poly(ether imide)s in a two-stage solution polymerization and imidization process. It was found that, in most cases, the dianhydrides with 4-phthalic anhydride units gave high-molecular-weight polymers with any of several aromatic diamines. In contrast, dianhydrides with 3-phthalic anhydride units gave, primarily, low-molecular-weight products. Examination of several low-molecular-weight products by electrospray-ionization mass spectrometry demonstrated that the products consisted of small oligomers, cyclic or linear according to the structure of the diamine. A series of high-molecular-weight polymers were prepared from 4,4‘-bis(4‘ ‘-aminophenoxy)biphenyl (BAPB) and each of several bis(ether anhydride)s with 3- or 4-phthalic anhydride units; the anhydrides had isopropylidine or hexafluoroisopropylidine units or ortho-methyl or ortho-tert-butyl substituents in the diol residues. These polymers were characterized in terms of their molecular weights and glass-transition temperatures. The gas permeabilities, positron annihilation, and dielectric relaxation behaviors of the polymers were investigated and their properties related to their molecular structures. Dielectric relaxation spectroscopy measurements indicate that, in this group of polymers, the rates of the local chain mobility are comparable and are able to facilitate gas diffusion. An apparent linear correlation between the permeation coefficients and free volume as determined by positron annihilation lifetime spectroscopy was observed with certain gases. Comparison of polymers with similar molecular structures indicated that isomeric polymers with 3- and 4-linked phthalimide units have similar properties and that the introduction of branched chains or fluorinated groups leads to an increase in the free volume and consequently increased permeability.