Comment gérer l'insoutenable ?

Corps mutilés, déformés, brûlés, ravagés par la maladie: dans de nombreux services, les soignants sont confrontés à des situations de l'ordre de l'insoutenable. Comment faire face sans être submergé de sentiments négatifs et surtout, comment entrer en relation avec des patients dont la souffrance psychique est immense

Wet spinning of solid polyamic acid fibers

The invention is a process for the production of solid aromatic polyamic acid and polyimide fibers from a wet gel or coagulation bath wet gel using N,N-dimethylacetamide (DMAc) solutions of the polyamic acid derived from aromatic dianhydrides such as 3,3',4,4' benzophenonetetra carboxylic dianhydride (BTDA) and aromatic diamines such as 4,4'-oxydianiline (4,4'-ODA). By utilizing the relationship among coagulation medium and concentration, resin inherent viscosity, resin percent solids, filament diameter, and fiber void content, it is possible to make improved polyamic acid fibers. Solid polyimide fibers, obtained by the thermal cyclization of the polyamic acid precursor, have increased tensile properties compared to fibers containing macropores from the same resin system

Wet spinning of solid polyamic acid fibers

The invention is a process for the production of solid aromatic polyamic acid and polyimide fibers from a wet gel or coagulation bath wet gel using N,N-dimethylacetamide (DMAc) solution of the polyamic acid derived from aromatic dianhydrides such as 3,3',4,4'-benzo phenone tetracarboxylic dianhydride (BTDA) and aromatic diamines such as 4,4'oxydianiline (4,4'-ODA). By utilizing the interrelationship between coagulation medium and concentration, resin inherent viscosity, resin percent solids, filament diameter, and fiber void content, it is possible to make improved polyamic acid fibers. Solid polyimide fibers, obtained by the thermal cyclization of the polyamic acid precursor, have increased tensile properties compared to fibers containing macropores from the same resin system

Low dielectric polyimide fibers

A high temperature resistant polyimide fiber that has a dielectric constant of less than 3 is presented. The fiber was prepared by first reacting 2,2-bis (4-(4aminophenoxy)phenyl) hexafluoropropane with 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride in an aprotic solvent to form a polyamic acid resin solution. The polyamic acid resin solution is then extruded into a coagulation medium to form polyamic acid fibers. The fibers are thermally cured to their polyimide form. Alternatively, 2,2-bis(4-(4-aminophenoxy)phenyl) hexafluoropropane is reacted with 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride to form a polyamic acid, and the polyamic acid is chemically converted to its polyimide form. The polyimide is then dissolved in a solvent to form a polyimide resin solution, and the polyimide resin is extruded into a coagulation medium to form a polyimide wet gel filament. In order to obtain polyimide fibers of increased tensile properties, the polyimide wet gel filaments are stretched at elevated temperatures. The tensile properties of the fibers were measured and found to be in the range of standard textile fibers. Polyimide fibers obtained by either method will have a dielectric constant similar to that of the corresponding polymer, viz., less than 3 at 10 GHz

Evaluation of high temperature polymers

The purpose of this paper is to identify and develop arc-track resistant insulation materials that can operate reliably at 300 C. In the first phase, high performance polymers are evaluated based on structure, thermal stability and electrical properties. Next, the polymers are ranked according to performance and experimental characterization. Then, experimental evaluations in wire configuration are conducted. And selection is made based on performance and commerical potential

Talking the Talk: Building Linguistic and Cultural Proficiency through Study Away

Language Immersion in Study Away Program