MICROBIAL-GROWTH ON FIBER-REINFORCED COMPOSITE-MATERIALS

Microorganisms may be responsible for physical and chemical changes in composite materials. Inoculation of a fungal consortium to pre-steril ized coupons of five composites resulted in deep penetration into the interior of all materials at a temperature of approximately 22 degrees C within 5 weeks. Scanning electron microscopy (SEM) showed that the inoculated composites were etched by the microorganisms. None of the f ive composites tested resisted fungal attack, Inoculation of extracts of these composites with the same fungi resulted in higher growth comp ared to the control, suggesting that chemical compounds leached from t he composites were utilized by microorganisms as a source of carbon an d energy. Studies with pure fibers used in the manufacture of composit e materials showed that the fungi grew rapidly on both glass and carbo n fibers in the presence of the fungal consortium. Our study indicates that microorganisms pose a threat to composite materials. We are curr ently investigating chemical and physical changes induced in these mat erials by the growth of fungi. Copyright (C) 1996 Published by Elsevie r Science Limited