A novel sulfonated polyimide having pendant sulfophenoxypropoxy groups was synthesized, and its electrolyte properties were investigated for fuel‐cell applications. A diamine monomer was synthesized from 3,3′‐dihydroxybenzidine in four steps, and its polymerization was performed with 1,4,5,8‐naphthalenetetracarboxylic dianhydride in the presence of triethylamine and benzoic acid in m‐cresol. A flexible, ductile, and self‐standing membrane was obtained via casting from an m‐cresol solution. Good thermal, hydrolytic, and oxidative stability was confirmed. The ionomer membrane showed very high proton conductivity of 1.0 S cm−1 at 120 °C and 100% relative humidity, which is higher than that of a Nafion membrane.

A series of novel polyimide electrolytes having long pendant sulfo-or phosphoalkoxy groups were synthesized for fuel-cell applications. Sulfodecyloxy-, phosphodecyloxy-, and sulfophenoxydodecyloxy-substituted benzidine monomers were synthesized from dihydroxybenzidine. These monomers were copolymerized with naphthalene tetracarboxylic dianhydride and fluorenylidene dianiline to give the corresponding polyimides. A flexible, ductile, and self-standing membrane was obtained via casting from the polyimide solution. Because the acid groups were on long pendant side chains and away from the main chains, the polyimide membrane showed improved oxidative and hydrolytic stability in comparison with the polyimides with sulfonic acid groups on the main chains or on the short side chains. High thermal stability (no glass-transition temperature and a decomposition temperature > 200 8C) was also obtained. The polyimide membrane displayed high proton conductivity of 10 À1 S cm À1 at 120 8C. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: [3995][3996][3997][3998][3999][4000][4001][4002][4003][4004][4005] 2006

β-Cyclodextrin derivatives, MRCD and p-MRCD, which have a 4-(dimethylamino)azobenzene moiety with a carbonyl substituent at 2′ and 4′ positions, respectively, have been prepared as color change indicators for detecting organic compounds. In a 10% ethylene glycol solution, MRCD and p-MRCD form intramolecular self-complexes in which the pendant dye moiety is included in the cyclodextrin cavity with an orientation parallel and perpendicular to the cyclodextrin axisis, respectively. When guest molecules are added to the acidic solutions of MRCD (pH 1.60) and p-MRCD (pH 2.40), they exhibit color changes from yellow to red for MRCD and from orange to red for p-MRCD. These color changes, which arise from the structural change of the dye moieties from the azo form to the azonium one, are caused when MRCD and p-MRCD undergo a conformational change in which the dye moieties inserted in the cyclodextrin cavities are excluded to outside of the cavities upon guest accommodation. The extent of the guest-induced color changes of MRCD and p-MRCD depend on the shape, size, number, and position of the functional group of guest molecules. Selectivities between MRCD and p-MRCD in guest detection are roughly parallel and reflected in the host-guest binding constants. Among guest molecules examined, ursodeoxycholic acid and chenodeoxycholic acid were detected by MRCD and p-MRCD with high sensitivities. 1-Adamanetanecarboxylic acid and (-)borneol were also detected with high sensitivities. In neutral conditions, however, the selectivity in guest detection of p-MRCD is different from that in acidic conditions as shown by the fact that, for example, 1-adamantanol and 2-adamantanol were detected by p-MRCD with larger sensitivities than 1-adamanetanecarboxylic acid. The result indicates that the ionic nature of the guest molecules is an important factor for detection of the guest molecules. All these results demonstrate that MRCD and p-MRCD can be used as color change indicators for detecting various organic compounds in aqueous solution.