Biodeterioration of coated nylon fabric

Biodegradation characteristics of nylon fabric coated with fluorocarbon pol ymer (oil and water repellent) and thiourea-formaldehyde (fire retardant) w ere studied. The fabric was exposed to soil burial, air exposure, and stand ard culture media for various intervals of time and evaluated for changes i n physicomechanical properties, oil and water repellency, air permeability, as well as flame-retardant properties. Significant falls in these properti es were observed, the extent of which was found to be maximum in the case o f soil burial followed by air medium and standard culture. Themogravimetric analysis showed enhanced heat stability of the unexposed fabric compared w ith base nylon. Exposure of the coated fabric to various biomedia caused ex tensive damage of the fire retardant material and also resulted in a signif icant reduction in the flame-resistant properties. Fluorocarbon material, o n the other hand, did not degrade on bioexposure and its presence improved the thermal stability of the coated fabric. Fourier transform infrared spec troscopy showed remarkable changes, e.g., peak shifts, intensity variations , as well as elimination of peaks in the case of soil burial compared with the unexposed sample. Scanning electron microscopy was used to investigate the changes in the surface topography associated with the degradation of th e coated fabric vis-a-vis those of the controlled one. (C) 2000 John Wiley & Sons, Inc.