The double bonds and aromaticity that impart high thermal stability in fibers often increase the absorption of LTV radiation, resulting in greater susceptibility to photodegradation. This study compares the resistance of three high-performance fibers (Nomex aramid, Kynol novoloid, and PBI) to accelerated light exposure. X-ray photoelectron spectroscopy (XPS) was used to evaluate the photochemical changes on the surfaces of the fibers. On the basis of the C 1 s core-level spectra and oxygen/carbon atomic ratios, the Nomex aramid fibers were photo-oxidized more rapidly than Kynol novoloid and PBI fibers. Similarly, Nomex aramid fibers exhibited more rapid strength losses than the other fibers. We propose that tautomerization inhibited photodegradation in the Kynol novoloid and PBI fibers. XPS core-level and valence-band spectra interpreted by ab initio calculations are shown to be valuable probes of photo-oxidation in fibers.

The influence of type of silk, age, and weighting agent on the physical and chemical deterioration of silk fabrics was evaluated by comparing t4e strength, elongation, amino acid content, viscosity, and infrared spectra of 54 undyed, historic silk fabrics with new silk plain weave fabric. Fiber fracture patterns also were characterized. Metallic elements present on the silks in various amounts, as determined by neutron activation analysis, were tin and to a lesser extent iron, aluminum, chromium, copper, barium, and arsenic. In general, tenacity, elongation, and viscosity were inversely related to the age of the silk. The variety of fiber fracture patterns in the historic silks reflected the diverse histories and causes of deterioration.

The potential of using 2450-MHz microwave radiation to dry and sterilize polyester and cotton fabrics was evaluated against Staphylococcus aureus, Escherichia coli, and Bacillus cereus. B. cereus spores were the most tolerant microorganisms of microwave radiation, and E. coli were the most sensitive. All S. aureus and E. coli cells were killed within seven minutes of exposure to microwave radiation. Fabric conditions of steam released and steam retained did not affect the percentage reduction in microorganisms. Microwave drying was substantially more effective than convection oven drying. Microwave exposure had no effect on the elongation of polyester and cotton, but cotton's strength decreased 10% after five minutes of microwave exposure.

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