Polyimides containing carbonyl and ether connecting groups. IV

Synthesis and Characterization of Aryl Phosphine Oxide Containing Thermoplastic Polyimides and Thermosetting Polyimides with Controlled Reactivity

Phosphorus-Containing Sulfonated Polyimides for Proton Exchange Membranes

Synthesis and characterization of the novel sulfonated BAPPO monomer and its use in the synthesis of a new phosphine oxide-based sulfonated polyimide are described. BTDA, 6FDA, and DDS were used as monomers in the polyimide synthesis. Sulfonated polyimide membranes were obtained by a solution thermal imidization method. The thermal behavior of the polymers was investigated by DSC and TGA. The m...

Orthogonal dipolar interactions between amide carbonyl groups.

Orthogonal dipolar interactions between amide C=O bond dipoles are commonly found in crystal structures of small molecules, proteins, and protein-ligand complexes. We herein present the experimental quantification of such interactions by employing a model system based on a molecular torsion balance. Application of a thermodynamic double-mutant cycle allows for the determination of the increment...

Reactivities of hydroxylamine and sodium bisulphite with carbonyl-containing haems and with the prosthetic groups of the erythrocyte green haemoproteins.

The reactivities of alkaline NH(2)OH and neutral NaHSO(3) with carbonyl and olefinic groups conjugated with the tetrapyrrole nucleus of haems were studied. The reactions were carried out with 2-3nmol of haem a, spirographis haem, isospirographis haem, 2,4-diacetyldeuterohaem and protohaem. Vinyl side chains were found to be insensitive to the chemical action of both alkaline NH(2)OH and neutral...

Preparation and Properties of Thermally Stable Polyureas Containing Ether and Ketone Units

The main objective of this search was to prepare novel soluble polyureas with improved thermal stability. Accordingly, a new types of polyureas was prepared through the polycondensation reaction of a prepared diamine containing ether, keto, and naphthyl groups with 4,4’-diphenylmethan diisocyanate (MDI), toluene-2,4-diisocyanate (TDI), and isophorone diisocyanate (IPDI) in N-methyl-2-pyrrol...