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Acrylics fiber formation

Peebles, L. H., Carbon fibers from acrylic precursors. In Carbon Fibers Formation, Structure, and Properties. CRC Press, Boca Raton, FL, 1995, pp. 7 26. [Pg.136]

Acrylamide with a demand of 200,000 tons year" is one of the most important commodities in the world. It is used for the preparation of coagulators, soil conditioners, stock additives for paper treatment, and in leather and textile industry as a component of synthetic fibers. Conventional chemical synthesis involving hydration of acrylonitrile with the use of copper salts as a catalyst has some disadvantages rate of acrylic acid formation higher than acrylamide, by-products formation and polymerization, and high-energy inputs. To overcome these limits since 1985, the Japanese company Nitto Chemical Industry developed a biocatalyzed process to synthesize... [Pg.400]

Crosslinking by chemical bond formation was tried with maleic anhydride. It is known that the addition of dienophiles such as maleic anhydride or acrylamide reduces color formation ( discoloration ) in acrylic fibers. A reasonable explanation for this phenomenon has been given by Marien It is based on a Diels-Alder reaction of the dienophile with cis-dienic structures created during the oligomerization of the... [Pg.42]

Acrylics and Modacrylics Polybenzimidazole and Carbon Fibers Polymerization Process Technology Fiber Formation... [Pg.441]

Of the fibers listed in Table II only the polyesters, polyamides, spandexes, acetates, and rayon are discussed in this chapter. While the acrylics and modacrylics are the third most important class of commercial fibers because their polymerization chemistry is also discussed in other chapters concerned with vinyl addition emulsion polymerizations, it will only be briefly summarized here. For the same reason polypropylene polymerization chemistry is also not covered in this section. However, two additional topics, carbon fiber formation and polybenzimidazoles have been included on the basis of the current Interest in high-performance fibers for composite materials. [Pg.442]

MAJOR USES Manufacture of chemicals including acrylic fiber, plastics, rubber elastomers, plasticizers, solvents, polymeric materials, dyes, pharmaceuticals, insecticides and nylon formation of high impact resins such as styrene acrylonitrile and acrylonitrile butadiene styrene. [Pg.12]

Polyester fibers are composed of linear chains of polyethylene terephthalate (PET), which produces benzene, benzoic acid, biphenyl, and vinyl terephthalate on pyrolysis. Acrylic fibers comprise chains made up of acrylonitrile units, usually copolymerized with less than 15% by weight of other monomers, e.g., methyl acrylate, methyl methacrylate, or vinylpyrrolidone. Thermolysis results in the formation of acrylonitrile monomer, dimers, and trimers with a small amount of the copolymer or its pyrolysis product. In this case, the acrylic is Orion 28, which contains methyl vinyl pyridine as comonomer. Residual dimethyl formamide solvent from the manufacturing process is also found in the pyrolysis products. Cotton, which is almost pure cellulose, comprises chains of glucose units. The pyrolysis products of cellulose, identified by GC/MS, include carbonyl compounds, acids, methyl esters, furans, pyrans, anhydrosugars, and hydrocarbons. The major pyrolysis products are levoglucosan (1,6-anhydro-B-D-glucopyranose) and substituted furans. [Pg.189]

The pyrolysis derivatization approach may also be used. THM results in the formation of dimethyl terephthalate when PET fibers are subjected to the procedure. Tetrabutyl ammonium hydroxide may be used to replace TMAH in the reaction to confirm the presence of vinyl acetate in acrylonitrile-vinyl acetate copolymer acrylic fibers. The derivatized product is butyl acetate. ... [Pg.189]

Figure 4.13 Crimp formation (microcrimp) and folding (macrocrimp). Source Reprinted with permission from von Falkai B, Dry Spinning Technology, Masson JC ed., Acrylic Fiber Technology and Applications, Marcel Dekker, New York, 143, 1995. Copyright 1995, CRC Press, Boca Raton, Florida. Figure 4.13 Crimp formation (microcrimp) and folding (macrocrimp). Source Reprinted with permission from von Falkai B, Dry Spinning Technology, Masson JC ed., Acrylic Fiber Technology and Applications, Marcel Dekker, New York, 143, 1995. Copyright 1995, CRC Press, Boca Raton, Florida.
Prasad G, Wet spinning of acrylic fiber and effects of spinning variables on fiber formation. Synthetic Fibers, 616, Jan and Mar 1985. [Pg.177]

Daumit GP, Ko YS, Slater CR, Venner JG, Young CC, Formation of melt-spun acrylic fibers which are particularly suited for thermal conversion to high strength carbon fibers, BASF, U.S. Pat., 4,921,656 1 May 1990. [Pg.178]

Takaku A, Shimazu J, Volume contraction and its significance in structural 1319, formation during the thermal stabilization of acrylic fibers, J Appl Polym Sci, 29, 1984. [Pg.266]

The production of many organic compounds requires the chlorination of feedstock chemicals (Table 3.3). This yields untreated wastewater that contains significant amounts of chlorinated methanes, ethanes, propanes, ethylenes, and propylenes. Other related processes such as chlorohydrina-tion and oxychlorination result in similar wastewater products. Furthermore, the use of vinyl chloride in the production of acrylic fibers and polyvinyl chloride resins yields chlorinated ethanes and ethylenes, whereas the production of epoxy resins results in the formation of dichloropropane and dichloropropylene through the use of epichlorohydrin (Wise and Fahrent-hold, 1981). [Pg.21]

Antistatic Agents Polar hydrophilic polymers applied as finishes or added to the polymer melt prior to fiber formation improve the static buildup characteristics of polyamides. Polyethylene glycols and acid-containing vinyl and acryl ic copolymers have been used, as have insoluble salts of amphoteric and cationic detergents. [Pg.208]

The fibrillar nature of drawn monofilaments becomes apparent in Figure 8.22. The filament ends of two different fracture events show a strong axial splitting. As concluded from the formation of small heads at the ends of some microfibrils the fibrillation must have occurred before the catastrophic fracture took place. Strong axial splitting is also known from polyamide 66, Kevlar [148], PETP, acrylic fibers, wool, human hair, and cotton fibers [85]. [Pg.201]

Uses Dispersant for calcareous soaps, dyestuffs, pigments, oils, and soivs. in textile industry aids level dyeing with good penetration and rubbing fastness protective colloid prevents bronzing and lacquers formation in acrylic fiber dyeing with basic dyestuffs... [Pg.309]

Although there are many variations on how carbon fibers are made, the typical process starts with the formation of PAN fibers from a conventional suspension or solution polymerization process between a mixture of acrylonitrile plastic powder with another plastic, such as methyl acrylate or methyl methacrylate, and a catalyst. The product is then spun into fibers, with the use of different methods, in order to be able to achieve the internal atomic structure of the fiber. After this, the fibers are washed and stretched to the desired fiber diameter. This step is sometimes called "spinning" and is also vital in order to align the molecules inside the fiber and thus provide a good basis for the formation of firmly bonded carbon crystals after carbonization [7]. [Pg.197]


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