Accession Number : ADA305278

Title :   Novel Improved PMR Polyimides.

Descriptive Note : Technical memo.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER

Personal Author(s) : Pater, Ruth H.

PDF Url : ADA305278

Report Date : 1982

Pagination or Media Count : 19

Abstract : N-phenylnadimide modified PMR resins and composites were investigated with the objective of improving the overall flow characteristics of PMR-15 type resins without compromising composite properties. A series of N-phenylnadimide (PN) modified PMR polyimide composites reinforced with Celion 6000 graphite fibers were investigated. The improved flow matrix resins consist of N-phenylnadimide (PN), monomethyl ester of 5-norbornene-2, 3-dicarboxylic acid (NE), dimethyl ester of 3,3',4,4'-benzophenonetetracarboxylic acid (BTDE), and 4,4'-methylenedianiline (MDA). Five modified PMR resin systems were formulated by the addition of 4 to 20 mole percent N-phenylnadimide to the standard PMR-15 composition. These formulations and the control PMR resin were evaluated for rheological characteristics. The initial thermal and mechanical properties of the PN modified PMR and the control PMR/Celion 6000 composites were determined. The elevated temperature flexural and interlaminar shear properties and the weight loss characteristics of the PMR composites isothermally exposed at 600 deg F in air for 1500 hours were evaluated. In addition, the effects of hydrothermal exposure on the glass transition temperatures and the elevated temperature flexural properties of the PMR composites were also investigated. The results of this study clearly showed that the addition of N-phenylnadimide to PMR-15 significantly improved the resin flow characteristics without sacrificing the composite properties. This study further revealed that concentrations of 4 and 9 mole percent PN appear to improve the therm-oxidative stability of PMR composites. jg p3

Descriptors :   *COMPOSITE MATERIALS, *POLYIMIDE RESINS, THERMAL PROPERTIES, FIBERS, MECHANICAL PROPERTIES, METHYL RADICALS, POLYMERS, HIGH TEMPERATURE, GRAPHITE, MATRIX MATERIALS, GLASS, TRANSITION TEMPERATURE, OXIDATION, RHEOLOGY, FLOW, ESTERS, WEIGHT REDUCTION, FLEXURAL PROPERTIES, CARBOXYLIC ACIDS.

Subject Categories : Plastics
      Organic Chemistry
      Polymer Chemistry
      Laminates and Composite Materials

Distribution Statement : APPROVED FOR PUBLIC RELEASE