Biodegradation of Composite Materials. Tri-Service Committee on CorrosionProceedings

摘要

The matrix- and interface-dominated properties of fiber-reinforced polymercomposites are known to be sensitive to absorbed moisture. In addition there is a potential for electrochemical corrosion when a carbon fiber composite is mechanically coupled with a metal, such as aluminum, in an aqueous environment. When these composite materials are exposed to aqueous solutions of nutrients, a substantial amount of biological activity is noted on and around the composites. The biological species has been identified as a fungus which is believed to be present in the as-sectioned composite specimens. In light of these observations the question arises of whether composite degradation in humid environments may be assisted or enhanced by biological microorganisms. A study was conducted to investigate this premise wherein biologically-active and sterile composite specimens were immersed in distilled water and a solution of nutrients. The growth of microorganisms was investigated using scanning electron microscopy, and their influence on mechanical property degradation was determined from measurements of interfacial and interlaminar shear strengths on model glass/epoxy composites and unidirectional graphite/epoxy composites, respectively. Mechanical couples of aluminum and a graphite/BMI laminate were also subjected to similar treatments in aqueous salt solutions, and corrosion of the laminates at the liquid/air interface was compared by SEM.