Accession Number : ADA309272
Title : Thermally Stable Polyimides from Solutions on Monomeric Reactants.
Descriptive Note : Technical note,
Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER
Personal Author(s) : Serafini, Tito T. ; Delvigs, Peter ; Lightsey, George R.
PDF Url : ADA309272
Report Date : JAN 1972
Pagination or Media Count : 16
Abstract : A method for preparing thermally stable resin-fiber-reinforced composites by using solutions of appropriate monomers is described. Solutions containing a dimethyl ester of an aryl tetracarboxylic acid, the monomethyl ester of nadic acid, and an aryl diamine were used to impregnate graphite fibers. Composites fabricated from these prepregs exhibited excellent thermooxidative stability and retention of mechanical properties at 315 C (600 deg F). These results compare favorably to those obtained from composites made from amide-acid prepolymers capped with reactive alicyclic rings. Monomeric solutions provide excellent shelf life and improved solubility compared to amide-acid prepolymer solutions.
Descriptors : *THERMAL STABILITY, *MONOMERS, *REACTANTS(CHEMISTRY), *POLYIMIDE RESINS, MECHANICAL PROPERTIES, METHYL RADICALS, FIBER REINFORCED COMPOSITES, GRAPHITE, CARBON FIBERS, AMINES, OXIDATION, ARYL RADICALS, AMIDES, SOLUBILITY, PREPREGS, ESTERS, CARBOXYLIC ACIDS, SHELF LIFE.
Subject Categories : Polymer Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE