Nylons fiber studies

Nylon fibers are used extensively in outdoor textiles and as a result are subject to sunlight, varying temperatures and acid precipitation. The degradation of nylon by light, heat, humidity and air polluted with sulfur dioxide has been widely studied (8-13). However, little data is available on the effect of aqueous acid on nylon in the presence of heat, light and moisture (i.e. acid rain conditions). Therefore, the purpose of this work was to determine the effect of acid rain conditions on nylon. The synergistic effects of aqueous acid, light and heat on nylon were also examined. 

Fabric. A plain weave fabric (Testfabrics 361) made from spun, delustered nylon 6,6 was used in this study. The fabric was chosen because it was representative of the type of nylon fiber used outdoors and the type of fabric used in previous photodegradation studies (21-23). 

Another example of the use of a wide-hne NMR for quantitative analyses is in the measurement of surface coating apphed to synthetic fibers and yams (Rodgers, 1994). This surface coating is called finish and serves to lubricate and control static on the fibers. The amount of finish apphed to fibers can be measured directly on a sample of nylon fiber by a low resolution (wide-hne) pulsed benchtop NMR in this study a 20 MHz proton QP20 from Oxford Instmments, Concord, MA, was used. Use of the NMR eliminated the need for costly and time consuming solvent extraction of the finish and subsequent determination by IR spectroscopy or gravimetry. The analyses required only 2-4 g of the sohd fibers and the finish could be determined accurately over a range of 0.5-1.5%. 

Other studies on the use of polypropylene fibers from carpet waste in concrete [81], used tire cords in concrete [82, 83], and using recycled nylon fibers to reduce plastic shrinkage cracking in concrete [84] have also been reported and reviewed [85]. Gordon et al. [86] used the waste nylon fibers and ground carpet to stabilize asphalt concrete. Increase of asphalt content in asphalt concrete is favorable because it leads to more durable roads. But it is limited by the resultant flushing and bleeding of pavements and possible permanent deformation of the pavement. Addition of 0.3 wt% waste fibers increased the allowed asphalt content by 0.3-0.4 wt%. 

Typical polymer materials studied in optical thin section include extrudates or molded parts, such as semicrystalline polyoxymethylene multiphase polymers, such as rubber toughened nylon filled polymers, such as carbon black filled nylon fibers, such as polyester and rayon and films which are too thick to transmit light. Two examples are of nylon imaged in polarized... 

A modified ebonite method was developed [134] to study the interfaces associated with polymer tire cords. Hre cords composed of PET, rayon or nylon fibers are generally bonded to rubber with a resorcinol-formaldehyde-latex (RFL) adhesive. The nature of the interfaces is of interest in tire... 

A nylon fiber is studied in different mounting media and is found to have a parallel refractive index (n ) of 1.575 and a perpendicular refractive index (n ) of 1.525. The fiber is found to have a circular cross section, and under PLM the center of the fiber appears to be a vivid green. What is the diameter of the fiber ... 

One of the most thoroughly researched applications of NIR to textile substrates is the measurement of substrate moisture content. Most of the textile moisture applications are for natural fiber products — wool, cotton, and so forth. For synthetic textile products, Elliott and coworkers [32] studied the spectral locations and the spectral influence of water on synthetic fiber spectra. Rodgers [17,33] measured the moisture content of nylon fibers by NIR spectroscopy both in the laboratory and at-line/ pseudo on-line. 

A modified ebonite method was developed [113] to study the interfaces associated with polymer tire cords. Tire cords composed of PET, rayon or nylon fibers are generally bonded to rubber with a resorcinol-formaldehyde-latex (RFL) adhesive. The nature of the interfaces are of interest in tire cord studies. OSO4 may be used to stain and harden the RFL, but the soft rubber is not affected by this treatment, and, in fact, it forms a barrier to stain penetration. The ebonite reaction hardens the rubber and hardens and stains the RFL while maintaining the geometrical integrity of the composite. 

Studies using gold decoration have been performed in several laboratories [282-286]. Thin solution cast films of nylon were studied by Spit [283], while Krueger and Yeh [284] studied stirred PE solutions which formed shish kebabs. Kojima and Magill [287] studied the morphology of spherulites of block copolymers by gold decorating sections. Shimamura [288] applied this method to the study of the internal structure of PE fibers. 

To undertake this study, a supply of real-world nylon fibers, and information regarding the dyes used to color them, was required. Shaw Industries, Inc. (Dalton, GA) supplied numerous colored nylon carpet samples with the associated dyes used to color the samples, and Collins Aikman (Dalton, GA) provided many colored nylon windings and information regarding the dyes used to color the fibers. Ciba Specialty Chemicals (High Point, NC) provided the dyes used to color those nylon windings. For both carpet- and winding samples, the manufacturers often used identical dye components to produce differenr colors by varying the ratio of dyes mixed. Only a small selection of the fiber and dye samples kindly provided by these manufacturers were used in this study. They are listed in Table 1. 

Further studies were conducted on the bending performance of nylon 6 electrospun nanofibers reinforced dental resin composites and it was revealed that the addition of 5% weight fi action improved the adhesion between nylon fibers and the matrix polymer [89],... 

Nylon-11. Nylon-11 [25035-04-5] made by the polycondensation of 11-aminoundecanoic acid [2432-99-7] was first prepared by Carothers in 1935 but was first produced commercially in 1955 in France under the trade name Kilsan (167) Kilsan is a registered trademark of Elf Atochem Company. The polymer is prepared in a continuous process using phosphoric or hypophosphoric acid as a catalyst under inert atmosphere at ambient pressure. The total extractable content is low (0.5%) compared to nylon-6 (168). The polymer is hydrophobic, with a low melt point (T = 190° C), and has excellent electrical insulating properties. The effect of formic acid on the swelling behavior of nylon-11 has been studied (169), and such a treatment is claimed to produce a hard elastic fiber (170). 

In a study of the adsorption of soap and several synthetic surfactants on a variety of textile fibers, it was found that cotton and nylon adsorbed less surfactant than wool under comparable conditions (59). Among the various surfactants, the cationic types were adsorbed to the greatest extent, whereas nonionic types were adsorbed least. The adsorption of nonionic surfactants decreased with increasing length of the polyoxyethylene chain. When soaps were adsorbed, the fatty acid and the aLkaU behaved more or less independently just as they did when adsorbed on carbon. The adsorption of sodium oleate by cotton has been shown independently to result in the deposition of acid soap (a composition intermediate between the free fatty acid and the sodium salt), if no heavy-metal ions are present in the system (60). In hard water, the adsorbate has large proportions of lime soap. 

The fiber industry has long been aware of PTT s good tensile elastic recovery [3], Ward et al. [4] studied the deformation behavior of PET, PTT and PBT fibers and found the tensile elastic recoveries were ranked in the unexpected descending order of PTT > PBT > PET. Chuah [47] found that the PTT elastic recovery and permanent set nearly tracked that of nylon 66 up to 30% strain (Figure 11.12). 

It is difficult to find any definitive information that indicates ozone damage as extensive as that suggested in the mri report. The latter identified cotton, nylon, and rayon as particularly susceptible to ozone. The oxidation of cellulose fibers by ozone was the subject of a study in 1952 that showed that dry cotton was not seriously degraded by ambient ozone. In more recent studies, these conclusions were confirmed. The only information available on fibers other than cotton addressed the effect of ozone on modacrylic, acrylic. Nylon 66, and polyester fabrics.The results indicated minimal effects on these fibers. 

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