Fiber applications

High performance fibers are generally characterized by remarkable unit tensile strength and resistance to heat, flame, and chemical agents that normally degrade conventional fibers. Applications include uses in the aerospace, biomedical, civil engineering, constmction, protective apparel, geotextiles, and electronic areas. 

Fiber. High molecular weight linear PPS is weU-suited for fiber applications. The inherent properties of PPS (flame resistance, chemical resistance, and thermal stability) make PPS fiber highly desirable ia textile applications (128). PPS fiber has been designated by the U.S. Federal Trade Commission as a new generic class of materials called sulfar. Typical fiber properties are listed ia Table 7 (see High performance fibers). 

Brasquet, C. and Le Cloirec, P., Adsorption onto activated carbon fibers Application to water and air treatments, Carbon, 1997, 35(9), 1307 1313. 

The spray is based upon either a natural plate-like material, such as vermiculite bound together with cement, or mineral fibers. Application is fast but not precise or clean, and is generally only suitable for areas where the steel will be hidden (by a false ceiling, for example). Sprays for external applications are available. However, the steel must first be provided with a compatible corrosion protection system. 

Polyester chemistry is the same as studied by Carothers long ago, but polyester synthesis is still a very active field. New polymers have been very recently or will be soon commercially introduced PTT for fiber applications poly(ethylene naph-thalate) (PEN) for packaging and fiber applications and poly(lactic acid) (PLA), a biopolymer synthesized from renewable resources (corn syrup) introduced by Dow-Cargill for large-scale applications in textile industry and solid-state molding resins. Polyesters with unusual hyperbranched architecture also recently appeared and are claimed to find applications as crosstinkers, surfactants, or processing additives. 

The number-average molar mass of thermoplastic polyesters varies from about 20,000 for film and fiber applications to 40,000 for injection-molding or blowmolding resins. Relationships between intrinsic or molten viscosity and molar mass have been published for PET,131-136 PBT,135,137 and PEN.138... 

The first use of PAs was in fiber applications, in which fibers were produced by melt spinning. These materials have a high strength and good wear resistance and can be easily dyed. The tension stiffening effect of the PA melt made the production of fibers witii homogeneous thickness possible. 

LED do not have sufficient power for single mode fiber applications which, because of the smaller cross-sections, require more powerful lasers. The CVD of LED and laser materials is described in Ch. 15. 

Fundamental of Polymer for Fiber Applications. American Fiber Manufacturers Association, http //www.fibersource.com/f-tutor/poly.htm... 

The primary crystalline polymer based on CHDM is the terephthalate, poly(1,4-cyclohexylenedimethylene terephthalate) (PCT). This polyester was originally developed for fiber applications but has since found wider utility as a reinforced polymer for injection molding and (when copolymerized with a small amount of isophthalic acid) as a material for crystallized food packaging trays. The key property of PCT which sets it apart from other thermoplastic polyesters in these latter applications is its melting point. 

PBT is easily made into fiber and monofilament and has been used in some fiber applications. For example, PBT fibers are used commercially as toothbrush bristles. Compared to PET, PBT fiber is more resistant to permanent deformation. Compared to nylon, PBT shows almost no change when exposed to moisture. PBT shows much more resistance to staining than nylon and can be colored by the use of pigments. However, PBT is more difficult to color by solution dying than nylon. PBT is not typically used in textile applications due to its perceived high price. 

For a long time, the fiber industry had been aware of PTT having desirable properties for fiber applications. In a 1971 patent [3], Fiber Industries, Inc. found PTT fiber to have a lower modulus, better bending and work recoveries than PET, and was therefore more suitable than PET for making fiberfill and carpets. Ward et al. [4] compared the mechanical properties of the three polyester fibers, and found PTT indeed had a better tensile elastic recovery and a lower modulus than both PET and PBT. These two properties are very desirable and are valued... 

Finally, the use of low-melting polyesters for low-melt fibers (melting point, 110-180 °C) should be pointed out, where TPA is replaced partly by IPA or adipic acid for bond fiber application. 

A suitable matrix for dye immobilization would permit the dye to respond reversibly and sensitively to the concentration of an analyte or several analytes. The ideal matrix for fiber applications is still in the early stages of development. 

Most of the polyester produced in the United States ends up in fiber applications—see the Fibers section below—but the growth of bottling applications, especially for beer, could change the percentages. 

Besides the high tenacity, a number of other properties are considered necessary for most fiber applications. Although no one polymer is superior in all of these categories, the list in Table 17.3 represents ideals for polymers being screened as fibers. 

Table 17.3 Ideal Properties of Polymers for Fiber Applications...

Liger-Belair, G., Voisin, C., and Jeandet, P. (2005b). Modeling non-classical heterogeneous bubble nucleation from cellulose fibers Applications to bubbling in carbonated beverages. /. Phys. Chem. B 109,14573-14580. 

Improved heat-resistant UV compositions for optical fiber applications These compositions are nonurethane UV cure compositions that have neither carbamate moieties nor long-chain poly(alkylene oxide) soft segments and exhibit inherently better thermal stability measured by thermogravimetric analysis (TGA) than typical coatings for optical fibers based on urethane acrylate oligomers. 

Fluorinated Polyimides for Optical, Microelectronic, and Fiber Applications... 

Perinones. The most important pigment in this family is the orange perinone, Pigment Orange 43 [4424-06-0] which is obtained by reaction of naphthalene-1,4,5,8-tetracarboxylic dianhydride with tf-phenylenediamine. The result is a mixture of the cis- and trans-isomers. The commercial product is the orange trans-compound which must be separated from the dull, bluish red cis-isomer, and then conditioned for pigment use. The pigment is fairly weatherfast and heat stable, and is used primarily in plastics and fiber applications. 

---