Accession Number : ADA182290
Title : Thermo-Oxidatively Stable Condensation Polyimides Containing 1,1,1-Triaryl-2,2,2-Trifluoroethane Dianhydride and Diamine Monomers.
Descriptive Note : Technical memo.,
Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CENTER
Personal Author(s) : Alston,William B ; Gratz,Roy F
PDF Url : ADA182290
Report Date : Jul 1987
Pagination or Media Count : 5
Abstract : Nine new condensation polyimides containing the trifluorophenylethylidene linkage were synthesized by the amic-acid route. Several other polyimides, including some with the hexafluoroisopropylidene linkage, were also prepared as controls. Amic-acid solutions were characterized by determining their inherent viscosities prior to thermal conversion into polyimide films. Glass transition temperatures (Tg), thermogravimetric analysis (TGA), and isothermal weight loss data (at 316 C, 371 C, 371 C under 0.5 MPa air pressure) were obtained for the films. The films were pulverized into molding powders which, in turn, were thermally processed under pressure into neat resin discs. The discs were also characterized by Tgs and 316 and 371 C isothermal weight losses. The film study identified two new polyimides with Tgs greater than 371 C and two new polyimides with low rates of weight loss. Keywords: Polyimides; Condensation; Polymers; High temperature; Stability; Glass transition temperature; Thermally; and Thermo-oxidatively.
Descriptors : *POLYMERS, *AMINES, *MONOMERS, *POLYIMIDE RESINS, AIR PRESSURE, DISKS, ISOTHERMS, WEIGHT REDUCTION, FILMS, THERMOGRAVIMETRIC ANALYSIS, GLASS, TRANSITION TEMPERATURE, LOW RATE, CONDENSATION, ENERGY CONVERSION, HEAT, VISCOSITY, MOLDINGS
Subject Categories : Polymer Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE