Clothing degradation

Figure 6. Reflectance as a function of wavelength of contemporary cotton print cloth degraded by a 100-Mrad dose of high-voltage electrons before and after Turnbults Blue test for carboxyl groups...

Figure 8. Relative concentration of carboxyl groups measured by Turrit bulVs Blue test in cotton print cloth degraded by heating at 168°C as a function of heating time. The concentrations of carboxyl groups in fabrics degraded by hydrolyzing 16 hr in 40% sulfuric acid at room temperature and by high-voltage electron irradiation at doses of 50 and 100 Mrad are also indicated.

Cotton Print Cloth Degraded by Electron Irradiation... 

Table III. Add-on and Strength of Cotton Print Cloth Degraded by Exposure to 100 Mr ad of Ionizing Radiation and Treated with Cotton Fibrils and Resins...

PPS fiber has excellent chemical resistance. Only strong oxidising agents cause degradation. As expected from inherent resia properties, PPS fiber is flame-resistant and has an autoignition temperature of 590°C as determined ia tests at the Textile Research Institute. PPS fiber is an excellent electrical iasulator it finds application ia hostile environments such as filter bags for filtration of flue gas from coal-fired furnaces, filter media for gas and liquid filtration, electrolysis membranes, protective clothing, and composites. 

They may be incompatible with the clothing or equipment being decontaminated (e.g., some organic solvents can permeate or degrade protective clothing)... 

The potential for wastes to permeate, degrade, or penetrate materials used for personal protective clothing and equipment, vehicles, tools, buildings, and structures... 

The spectral ratios (S.R.) given in Tables II and III show that Nuclepore filters and copper discs have the highest S.R., indicating that less degradation of the spectra, and hence, highest energy resolution, occurs. It should be noted, that except for cotton cloth (Table II), there seems to be a correlation between the S.R. and the activity plated-out on the material. 

In another, similar study, Mukundan et al. [260] performed 100 freeze-thaw cycles (from -40 to 80°C) with different types of CFPs and CCs. After 100 cycles, no obvious degradation was observed in the carbon cloth DL in fact, the performance of the fuel cell slightly improved. On the other hand, after 45 cycles, the CFPs showed significant breakage of the carbon fibers at the edges between the flow channels and the landing widths (or ribs). Thus, it was concluded that this breakage could potentially become a serious failure mechanism in PEM fuel cells when the system was started at subzero temperatures. 

An example of this kind of work involves the enzyme subtilisin, frequently used as an additive in laundry detergents because it attacks the proteins that soil clothing. The problem, however, is that subtilisin is easily destroyed by bleaches with which a detergent is often used. Research showed that subtilisin is sensitive to bleach because a single amino acid in its primary structure—a methionine at position 22—is destroyed by bleach. By replacing this methionine with an amino acid that is not sensitive to attack by bleach, then, researchers were able to synthesize a new form of subtilisin that did not degrade in the presence of bleach for use in laundry detergents. 

In addition, the shapes of the curves are the same as those found from measurements of degree of polymerization, color change and tear strength for the degradation of cotton, linen and rayon cloth artificially aged under the same conditions (12. 14. 21). 

It was further shown that treatment with sodium borohydride (1) effectively reduces the extent and rate of degradation of both new and aged Cellophane films, in agreement with previous reports on cotton cloth, and (2) reduces both UV and IR absorbance to negligible levels indicating that acid moieties on the cellulose chains, if present, are in negligible quantities. 

Air aging after 31 hours leaves the cloth in a friable and brittle state where the extent of degradation is very high. 

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