Fungal degradation of fiber-reinforced composite materials

Book · Sun Dec 01 04:00:00 EST 1996

OSTI ID:397839

Gu, J D; Lu, C; Mitchell, R ^[1]; Thorp, K; Crasto, A ^[2]

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1. Harvard Univ., Cambridge, MA (United States)
2. Univ. of Dayton Research Inst., OH (United States). Nonmetallic Materials Div.

The authors described in a previous report that a fungal consortium isolated from degraded polymeric materials was capable of growth on pre-sterilized coupons of five composites, resulting in deep penetration into the interior of all materials within 5 weeks. Data describing the utilization of composite constituents as nutrients for the microflora are described in this paper. Increased microbial growth was observed when composite extract was incubated with the fungal inoculum at ambient temperatures. Scanning electron microscopic (SEM) observation of carbon fibers incubated with a naturally developed population of microorganisms showed the formation of bacterial biofilms on the fiber surfaces, suggesting possible utilization of the fiber chemical sizing as carbon and energy sources. Electrochemical impedance spectroscopy (EIS) was used to monitor the phenomena occurring at the fiber-matrix interfaces. Significant differences were observed between inoculated and sterile panels of the composite materials. A progressive decline in impedance was detected in the inoculated panels. Several reaction steps may be involved in the degradation process. Initial ingress of water into the resin matrix appears to be followed by degradation of fiber surfaces, and separation of fibers from the resin matrix. The authors` investigation suggested that composite materials are susceptible to microbial attack by providing nutrients for growth.

• OSTI ID: 397839
• Report Number(s): CONF-960389--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BACTERIA
BIODEGRADATION
CARBON FIBERS
COMPOSITE MATERIALS
DAMAGE
ELECTROCHEMISTRY
EPOXIDES
EXPERIMENTAL DATA
FUNGI
IMPEDANCE
INTERFACES
SCANNING ELECTRON MICROSCOPY
SPECTROSCOPY