Accession Number : ADA303735

Title :   Development of High Temperature Resistant Graphite Fiber Coupling Agent

Descriptive Note : Contract rept.,

Corporate Author : GENERAL ELECTRIC CO PHILADELPHIA PA

Personal Author(s) : Griffin, Richard N.

PDF Url : ADA303735

Report Date : FEB 1975

Pagination or Media Count : 132

Abstract : Ten surface treatments were investigated as potential coupling agents to improve the elevated temperature shear strength retention of polyimide/graphite and polyphenylquinoxaline/graphite composites. The potential coupling agents were evaluated by fiber strand tensile tests, fiber and composite weight losses at 533 and 588K, and by interlaminar shear strength retention at 533 and 588K. The two surface treatments selected for more extensive evaluation were a coating of Ventromer T-1, a complex organometallic reaction product of titanium tetrachloride and trimethyl borate, and a polyphenylquinoxaline (PPQ) sizing which was pyrolyzed in nitrogen to form a carbonaceous layer on the fiber. Pyrolyzed polyphenylquinoxaline is a very satisfactory coupling agent for polyimide/Thornel 300 graphite fiber composites. During 1000 hours aging at 588K such composites lose a little over half their transverse tensile strength, and suffer a slight loss in flexural modulus. However, no degradation of flexural strength or interlaminar shear strength occurs during 1000 hours aging at 588K. None of the coupling agents examined in the course of this work had a markedly beneficial effect with polyphenylquinoxaline composites. This may indicate simply that none of them were well suited to use with polyphenylquinoxaline, or it may indicate that the weak point of the PPQ composites is not the carbon/resin interface. jg

Descriptors :   *FIBERS, *HIGH TEMPERATURE, *RESISTANCE, *GRAPHITE, *COUPLINGS, TEST AND EVALUATION, TENSILE STRENGTH, AGING(MATERIALS), DEGRADATION, METHYL RADICALS, INTERFACES, LAYERS, POLYMERS, COMPOSITE MATERIALS, SURFACE FINISHING, TENSILE PROPERTIES, ORGANOMETALLIC COMPOUNDS, CARBON, NITROGEN, COATINGS, RETENTION(GENERAL), FLEXURAL STRENGTH, CHLORIDES, LOSSES, LAMINAR FLOW, LOW STRENGTH, STRANDS, PYROLYSIS, BORATES, TRANSVERSE, TITANIUM COMPOUNDS, SHEAR STRENGTH, POLYIMIDE RESINS.

Subject Categories : Inorganic Chemistry
      Polymer Chemistry
      Laminates and Composite Materials
      Textiles

Distribution Statement : APPROVED FOR PUBLIC RELEASE