Synthetic fiber-forming polymers

Polyesters. The first synthetic fiber forming polymer produced by Carothers and coworkers was an aliphatic polyester made from trimethylene glycol and a hexadecamethylene dicarboxylic acid. This polymer was low-melting (70°C) and hydrolytically unstable. In 1941, Whinfield and Dickson synthesized the first high-melting symmetrical linear aromatic polyester, polyethylene terephthalate, and found it to be a very useful product. ... 

Synthetic fiber-forming polymers Polyethylene terephthalate... 

Microcellular foams can be obtained by flash spinning and are usually prepared at relatively high polymer concentrations in the spinning solution, i.e., at least 40% synthetic fiber-forming polyolefin. 

Synthetic fibers are generally made from polymers whose chemical composition and geometry enhance intermolecular attractive forces and crystallization. A certain degree of moisture affinity is also desirable for wearer comfort in textile applications. The same chemical species can be used as a plastic, without fiber-like axial orientation. Thus most fiber forming polymers can also be used as plastics, with adjustment of molecular size if necessary to optimize properties for particular fabrication conditions and end u.ses. Not all plastics can form practical fibers, however, because the intermolecular forces or... 

Chemical Abstracts (19) will probably satisfy most requirements for literature on research in fiber-forming materials. The first United States articles on synthetic fibers and fiber-forming polymers appeared largely in the J ournal of the American Chemical Society (32), The rapid growth of polymer science fostered the establishment of the Journal of Polymer Science (35) in 1945. The usefulness of this monthly journal as a medium for the publication of fundamental research papers has also been enhanced by the fact that details appear in this journal that would ordinarily be edited out of other journals. 

For the purpose of discussion of the chemistry and technology of man-made, fiber-forming polymers, the term "synthetic fiber" will be used to denote all man-made fibers manufactured from noncellulosic raw materials. The term "cellulosics" will apply to those man-made fibers that are manufactured from cellulosic raw materials. The term "man-made fibers" will apply to all fibers except the naturally occurring cellulosic and protein fibers. 

Textile products are also finally bleached and then dyed. Physical and/or chemical processes participate in dying processes and discussion of these is more a domain for textile chemistry. Here, the dyeability of synthetic fibers can be increased by polymerizing in small quantities of certain comonomers which have a better affinity to the dyestuffs than the monomeric units of the actual fiber forming polymer. For example, certain acidic comonomers I and II in PET and PA for basic dyestuffs, basic comonomer III in PET and PA for acidic dyestuffs, acidic comonomers IV-VI in PAN for basic dyestuffs, and basic comonomers VII-IX in PAN for acidic dyestuffs ... 

Work in our own laboratories has shown, however, that in the presence of conventional flame retardants, nanoclays can promote additive and synergistic effects in PA6, PA6,6 Aims that have been used as models for respective fibers. This work has provided evidence that significant reductions in flame retardant additive concentrations may be achievable, as has been noted for other polymers in Section 11.3.1. Normally, minimal flame retardant additive contents of about 15 to 20% w/w are required, which are too high for inclusion in conventional synthetic fibers. This is because for fusible fiber-forming polymers snch as PA6, PA6,6, PET, and polypropylene, flame retardant property trends versns concentration are not linear but follow an S-shaped curve. " This phenomenon is believed to be a consequence of the need to generate a threshold char level having an extended coherence throughout the polymer. It follows that this will... 

Research continued into fiber-forming polymers, but the next new fully synthetic yam was not discovered until the 1930s, when Wallace Hume Carothers, working for DuPont, discovered and developed nylon. This was first commercialized in 1938 and was widely developed during the 1940s to become one of the major yam types used. Continuing research led to the discovery of polyester in 1941, and over the ensuing... 

Olefin fibers, also called polyolefin fibers, are defined as manufactured fibers in which the fiber-forming substance is a synthetic polymer of at least 85 wt % ethylene, propjiene, or other olefin units (1). Several olefin polymers are capable of forming fibers, but only polypropylene [9003-07-0] (PP) and, to a much lesser extent, polyethylene [9002-88-4] (PE) are of practical importance. Olefin polymers are hydrophobic and resistant to most solvents. These properties impart resistance to staining, but cause the polymers to be essentially undyeable in an unmodified form. 

The Textile Eiber Product Identification Act (TEPIA) requires that the fiber content of textile articles be labeled (16). The Eederal Trade Commission estabhshed and periodically refines the generic fiber definitions. The current definition for a polyester fiber is "A manufactured fiber ia which the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of an ester of a substituted aromatic carboxyUc acid, including but not restricted to terephthalate units, and para substituted hydroxyben2oate units."... 

Synthetic fiber producers have attempted to minimise the tendency for pilling by several methods, one of which is to reduce polymer molecular weight. The resulting lower strength fiber would break away from the fabric surface more readily. Another method for reducing pilling is to notch or etch the fiber surface either before or after incorporation in fabric form. 

It is difficult for dye solutions in water to penetrate synthetic fibers such as polyester, cellulose triacetate, polyamides, and polyacryUcs which are somewhat hydrophobic. The rate of water imbibition differs with each fiber as shown in Table 1 as compared to viscose (see Fibers, regenerated CELLULOSics), which imbibes water at the rate of 100% (1). The low imbibition rate is attributed to the high T obtained when the polymeric fibers are drawn. During this drawing operation the polymer chains become highly oriented and tightly packed, forming a stmcture practically free of voids. 

Why Do We Need to Know This Material The existence of compounds is central to the science of chemistry and by seeing how bonds form between atoms, we come to see how chemists design new materials. Research into artificial blood, new pharmaceuticals, agricultural chemicals, and the polymers used in materials such as compact discs, cellular phones, and synthetic fibers is based on an understanding of how atoms link together. 

Abandoning the hunt for linear, fiber-forming molecules, he turned to polymer ring compounds. Before Carothers, cyclic compounds were so difficult to make that no one studied them, but his group had tasted scientific blood and was happily publishing papers. When they discovered a series of ring compounds that produce synthetic scents, Du Pont sold the compounds to the perfume industry. The cyclic compounds were the last of Carothers fundamental scientific studies. After completing them, he drifted for a while, unclear as to what direction his research should take. 

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