Accession Number : ADA302686

Title :   Investigation of Degradation Mechanisms in Composite Matrices.

Descriptive Note : Contract rept. 25 Jul 78-25 Mar 80,

Corporate Author : IIT RESEARCH INST CHICAGO IL

Personal Author(s) : Giori, C. ; Yamauchi, T.

PDF Url : ADA302686

Report Date : JUN 1982

Pagination or Media Count : 111

Abstract : Degradation mechanisms have been investigated for graphite/polysulfone and graphite/epoxy laminates exposed to ultraviolet and high-energy electron radiations in vacuum up to 960 equivalent sun hours and 10(exp 9) rads respectively. Based on GC and combined GC/MS analysis of volatile by-products evolved during irradiation, several free radical mechanisms of composite degradation have been identified. The radiation resistance of different matrices has been compared in terms of G values and quantum yields for gas formation. All the composite materials evaluated have shown high electron radiation stability and relatively low ultraviolet stability as indicated by low G values and high quantum yields for gas formation. Mechanical property measurements of irradiated samples did not reveal significant changes, with the possible exception of UV exposed polysulfone laminates. Hydrogen and methane have been identified as the main by-products of irradiation, along with unexpectedly high levels of CO and CO2.

Descriptors :   *DEGRADATION, *COMPOSITE MATERIALS, *MATRIX MATERIALS, *EPOXY LAMINATES, *GRAPHITE EPOXY COMPOSITES, *POLYSULFONES, MEASUREMENT, RADIATION, MECHANICAL PROPERTIES, STABILITY, ULTRAVIOLET RADIATION, EXPOSURE(GENERAL), LAMINATES, VACUUM, HYDROGEN, GASES, HIGH ENERGY, ELECTRON ENERGY, SAMPLING, QUANTUM EFFICIENCY, VOLATILITY, IRRADIATION, CARBON MONOXIDE, ELECTRON IRRADIATION, METHANE, FREE RADICALS, CARBON DIOXIDE, GAS CHROMATOGRAPHY, MASS SPECTROMETRY, RADIATION RESISTANCE.

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE