Poly fiber

ETHYLENE We discussed ethylene production in an earlier boxed essay (Section 5 1) where it was pointed out that the output of the U S petrochemi cal industry exceeds 5 x 10 ° Ib/year Approximately 90% of this material is used for the preparation of four compounds (polyethylene ethylene oxide vinyl chloride and styrene) with polymerization to poly ethylene accounting for half the total Both vinyl chloride and styrene are polymerized to give poly(vinyl chloride) and polystyrene respectively (see Table 6 5) Ethylene oxide is a starting material for the preparation of ethylene glycol for use as an an tifreeze in automobile radiators and in the produc tion of polyester fibers (see the boxed essay Condensation Polymers Polyamides and Polyesters in Chapter 20)... 

The production of polyester fibers leads that of all other types Annual United States production of poly ester fibers is 1 6 million tons versus 1 4 million tons for cotton and 1 0 million tons for nylon Wool and silk trail far behind at 0 04 and 0 01 million tons re spectively... 

Fluorinated ethylene-propylene resin Poly(vinylidene fluoride) Ethylene-tetrafluoroethylene copolymer Ethylene- chlorotrifluoro- ethylene copolymer Cellulose- filled Glass-fiber- reinforced... 

Low viscosity 30% glass-fiber reinforced Poly(butylene terephthalate) Poly(ethylene terephthalate) ... 

Poly(methyl Ultra high- Glass-fiber- Ethylene-... 

Properties Unfilled 20% glass-fiber- reinforced Unfilled 20% glass-fiber- reinforced Poly(ether sulfone) Poly(phenyl sulfone)... 

Poly(vinyl chloride) and poly(vinyl acetate) Poly(vinyl chloride), 15% glass-fiber-reinforced Chlorinated poly(vinyl chloride) Poly(vinyl butyral), flexible ... 

Solid-phase microextractions also have been developed. In one approach, a fused silica fiber is placed inside a syringe needle. The fiber, which is coated with a thin organic film, such as poly(dimethyl siloxane), is lowered into the sample by depressing a plunger and exposed to the sample for a predetermined time. The fiber is then withdrawn into the needle and transferred to a gas chromatograph for analysis. 

The ethylene glycol liberated by reaction (5.L) is removed by lowering the pressure or purging with an inert gas. Because the ethylene glycol produced by reaction (5.L) is removed, proper stoichiometry is assured by proceeding via the intermediate, bis(2-hydroxyethyl) terephthalate otherwise the excess glycol used initially would have a deleterious effect on the degree of polymerization. Poly(ethylene terephthalate) is more familiar by some of its trade names Mylar as a film and Dacron, Kodel, or Terylene as fibers it is also known by the acronym PET. 

PVDFmonofilament [FLUORINECOMPOUNDS,ORGANIC - POLY(VINYLIDENEFLUORIDE)] (Volll) -carbon fibers in [CARBON AND GRAPHITE FIBERS] (Vol 5)... 

Poly(vinylidene fluoride), tangential flow. Regenerated cellulose hoUow fiber. Polyacrylonitrile hoUow fiber. 50-nmhead, 150-nm tail. 

The protonated form of poly(vinyl amine) (PVAm—HCl) has two advantages over many cationic polymers high cationic charge densities are possible and the pendent primary amines have high reactivity. It has been appHed in water treatment, paper making, and textiles (qv). The protonated forms modified with low molecular weight aldehydes are usehil as fines and filler retention agents and are in use with recycled fibers. As with all new products, unexpected appHcations, such as in clear antiperspirants, have been found. It is usehil in many metal complexation appHcations (49). 

The majority of xylenes, which are mostly produced by catalytic reforming or petroleum fractions, ate used in motor gasoline (see Gasoline and other MOTORFUELs). The majority of the xylenes that are recovered for petrochemicals use are used to produce PX and OX. PX is the most important commercial isomer. Almost all of the PX is converted to terephthaUc acid and dimethylterephthalate, and then to poly(ethylene terephthalate) for ultimate use in fibers, films, and resins. 

The beater additive process starts with a very dilute aqueous slurry of fibrous nitrocellulose, kraft process woodpulp, and a stabilizer such as diphenylamine in a felting tank. A solution of resin such as poly(vinyl acetate) is added to the slurry of these components. The next step, felting, involves use of a fine metal screen in the shape of the inner dimensions of the final molded part. The screen is lowered into the slurry. A vacuum is appHed which causes the fibrous materials to be deposited on the form. The form is pulled out after a required thickness of felt is deposited, and the wet, low density felt removed from the form. The felt is then molded in a matched metal mold by the appHcation of heat and pressure which serves to remove moisture, set the resin, and press the fibers into near final shape (180—182). 

However, because of the low melting poiats and poor hydrolytic stabiUty of polyesters from available iatermediates, Carothers shifted his attention to linear ahphatic polyamides and created nylon as the first commercial synthetic fiber. It was nearly 10 years before. R. Whinfield and J. T. Dickson were to discover the merits of poly(ethylene terephthalate) [25038-59-9] (PET) made from aromatic terephthaUc acid [100-21-0] (TA) and ethylene glycol [107-21-1] (2G). 

Poly(ethylene terephthalate), the predominant commercial polyester, has been sold under trademark names including Dacron (Du Pont), Terylene (ICI), Eortrel (Wellman), Trevira (Hoechst-Celanese), and others (17). Other commercially produced homopolyester textile fiber compositions iaclude p oly (1,4-cyc1 oh exa n e- dim ethyl en e terephthalate) [24936-69-4] (Kodel II, Eastman), poly(butylene terephthalate) [26062-94-2] (PBT) (Trevira, Hoechst-Celanese), and poly(ethylene 4-oxyben2oate) [25248-22-0] (A-Tell, Unitika). Other polyester homopolymer fibers available for specialty uses iaclude polyglycoHde [26124-68-5] polypivalolactone [24937-51-7] and polylactide [26100-51-6],... 

Vinal fibers, or poly(vinyl alcohol) fibers, are not made in the United States, but the fiber is produced commercially in Japan, Korea, and China where the generic name vinylon is used. These materials are the subject of this article (see also Vinyl polymers, vinyl alcohol polymers). 

Vinyl alcohol does not exist as a monomer, but Herrmann and Haehnel (1) were able to obtain the desired product poly(vinyl alcohol) [9002-89-5] (PVA), by polymerizing vinyl acetate and then hydrolyzing the resultant poly(vinyl acetate). This process is employed for the commercial production of PVA even now. The principal concern of the discoverers was development of a suture for surgical operations the fiber then obtained was not suited for clothing use (2). 

In conventional tenter orientation, the sequence of steps is as described above (MD—TD). In some cases it is advantageous to reverse the draw order (TD—MD) or to use multiple draw steps, eg, MD—TD—MD. These other techniques are used to produce "tensilized" films, where the MD tensile properties are enhanced by further stretching. The films are generally unbalanced in properties and in extreme cases may be fibrillated to give fiber-like elements for special textile appHcations. Tensilized poly(ethylene terephthalate) is a common substrate for audio and video magnetic tape and thermal transfer tape. 

Polyester Fibers Containing Phosphorus. Numerous patents describe poly(ethylene terephthalate) (PET) flame-retarded with phosphoms-containing diftmctional reactants. At least two of these appear to be commercial. 

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