Effects of space radiation on a chemically modified graphite-epoxy composite material. Interim report

Technical Report · Wed Oct 01 00:00:00 EDT 1986

OSTI ID:6856575

Reed, S M; Herakovich, C T; Sykes, G F

The effects of the space environment on the engineering properties and chemistry of a chemically modified T300/934 graphite-epoxy composite system are characterized. The material was subjected to 1.0 x 10 to the 10th power rads of 1.0 MeV electron irradiation under vacuum to simulate 30 years in geosynchronous earth orbit. Monotonic tension tests were performed at room temperature (75 F/24 C) and elevated temperature (250 F/121 C) on 4-ply unidirectional laminates. From these tests, inplane engineering and strength properties (E sub 1, E/sub 2/, Nu/sub 12/, G/sub 12/, X/sub T/, Y/sub T/) were determined. Cyclic tests were also performed to characterize energy dissipation changes due to irradiation and elevated temperature. Large diameter graphite fibers were tested to determine the effects of radiation on their stiffness and strength. No significant changes were observed. Dynamic-mechanical analysis demonstrated that the glass transition temperature was reduced by 50 F(28 C) after irradiation. Thermomechanical analysis showed the occurrence of volatile products generated upon heating of the irradiated material. The chemical modification of the epoxy did not aid in producing a material which was more radiation resistant than the standard T300/934 graphite-epoxy system. Irradiation was found to cause crosslinking and chain scission in the polymer. The latter produced low molecular weight products which plasticize the material at elevated temperatures and cause apparent material stiffening at low stresses at room temperature.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (USA). Langley Research Center
• OSTI ID: 6856575
• Report Number(s): N-87-10977; NASA-TM-89232; NAS-1.15:89232; CCMS-86-06; VPI-E-86-19; IR-60; TRN: 87-005282
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBON FIBERS
PHYSICAL RADIATION EFFECTS
COMPOSITE MATERIALS
ELECTRON BEAMS
EPOXIDES
EXPERIMENTAL DATA
GRAPHITE
HIGH TEMPERATURE
HIGH VACUUM
TENSILE PROPERTIES
BEAMS
CARBON
DATA
ELEMENTAL MINERALS
ELEMENTS
FIBERS
INFORMATION
LEPTON BEAMS
MATERIALS
MECHANICAL PROPERTIES
MINERALS
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PARTICLE BEAMS
RADIATION EFFECTS
360605* - Materials- Radiation Effects