Nylon-3 fibers

Also called aramid fibers. See High Performance Reinforcements, Aramid Fibers in this chapter. 

Rutishauser et al. (1972) demonstrated that the binding of cells to antigen fibers is inhibited by soluble antigen. Kiefer (1973) studied the conditions of release of cells from the fibers and he reported that cells bound at 4° C for more than twelve hours can be released quantitatively from the fiber at temperatures above 22° C within two hours in a fully viable state. Kiefer suggests that capping of lymphocytes is involved in the release of cells from the fibers. Functional studies on the ability of the retained and depleted cells 

Antibody Response Reference anti-SRC anti-ChRC 

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Nylon apparel Nylon bearings Nylon blends Nylon-cellulose Nylon-clay hybrid Nylon-cotton Nylon-cotton blends Nylon engineering Nylon fibers Nylon hollow fibers Nylon-6,1 [25722-07-0]... 

The physical properties of these fibers are compared with those of natural fibers and other synthetic fibers in Table 1. Additional property data may be found in compilations of the properties of natural and synthetic fibers (1). Apart from the polyolefins, acryhcs and nylon fibers are the lightest weight fibers on the market. Modacryhcs are considerably more dense than acryhcs, with a density about the same as wool and polyester. 

Resistance to Microorganisms and Insects. Resistance of triacetate to microorganisms, based on soil-burial tests, is high, approaching that of polyester, acryUc, and nylon fibers. Sod-burial test results on acetate, triacetate, and cotton are shown in Figure 8. Neither acetate nor triacetate fiber is readdy attacked by moths or carpet beedes. 

Fig. 1. (a) World production of nylon fiber (11) (b) world consumption of nylon resins (12). 

Tensile Properties. Tensile properties of nylon-6 and nylon-6,6 yams shown in Table 1 are a function of polymer molecular weight, fiber spinning speed, quenching rate, and draw ratio. The degree of crystallinity and crystal and amorphous orientation obtained by modifying elements of the melt-spinning process have been related to the tenacity of nylon fiber (23,27). 

Because of water s plasticizing effect, the water content of nylon fibers and fabrics must be known and controlled when measuring physical properties. Prior to the measurement, samples are conditioned at a specified temperature and rh for at least 24 h. 

Fig. 13. Typical nylon fiber cross-section shapes.

Bicomponent technology has been used to introduce functional and novelty effects other than stretch to nylon fibers. For instance, antistatic yams are made by spinning a conductive carbon-black polymer dispersion as a core with a sheath of nylon (188) and as a side-by-side configuration (189). At 0.1—1.0% implants, these conductive filaments give durable static resistance to nylon carpets without interfering with dye coloration. Conductive materials such as carbon black or metals as a sheath around a core of nylon interfere with color, especially light shades. 

Phloroglucinol is Hsted in the Colourindex as Cl Developer 19. It is particularly valuable in the dyeing of acetate fiber but also has been used as a coupler for azoic colors in viscose, Odon, cotton (qv), rayon, or nylon fibers, or in union fabrics containing these fibers (157). For example, cellulose acetate fabric is treated with an aromatic amine such as (9-dianisidine or a disperse dye such as A-hydroxyphenylazo-2-naphthylamine and the amine diazotizes on the fiber the fabric is then rinsed, freed of excess nitrite, and the azo color is developed in a phloroglucinol bath at pH 5—7. Depending on the diazo precursor used, intense blue to jet-black shades can be obtained with excellent light-, bleach-, and mbfastness. 

The early yellow disperse dyes were based on phenolic coupling components, eg, Cl Disperse Yellow 3 (92) (diazotized 4-arninoacetanihde coupled to -cresol) which is still used today for the coloration of cellulose acetate and nylon fibers. 

Nylons have a variety of uses ranging from tire cord to carpet to hosiery. The most important application is cord followed by apparel. Nylon staple and filaments are extensively used in the carpet industry. Nylon fiber is also used for a variety of other articles such as seat belts, monofilament finishes, and knitwear. Because of its high tenacity and elasticity, it is a valuable fiber for ropes, parachutes, and underwear. 

The 1997 U.S. production of nylon fibers was approximately 2.9 billion pounds. 

The elasticity of nylon fibers is due in part to hydrogen bonds between adjacent polymer chains. These hydrogen bonds join carbonyl oxygen atoms on one chain to NH groups on adjacent chains (Figure 23.4). 

Nylon fibers are semicrystalline, that is, they consist of crystallites separated by amorphous regions. Hydrogen bonding is an important secondary valence interaction in nylon-6 and nylon-6,6. Individual chains in the microcrystalline regions of nylons are held together by hydrogen bonds. Nylons are resistant to aqueous alkali but deteriorate more readily on exposure to mineral acids. 

FIGURE 19.12 A rather crude nylon fiber. can be made by dissolving the salt of an amine in water and dissolving the acid in tfcg a layer of hexane, which floats on the water. The polymer forms at the interface f of the two lavers, and a long string can be slowly pulled out. 

FIGURE 19.13 The strength of nylon fibers is an indication of the strength of the hydrogen bonds between neighboring polyamide chains. 

A typical nylon fiber has a molecular mass of approximately 12 000 amu. Approximately how many monomer units are present in this fiber ... 

A nylon fiber has uniaxial orientation in which the polymer chains are parallel to the fiber axis. Is Et greater than ET1 Is Gr/ greater than G, 7 Why ... 

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