Qiana fibers

HMD was originally produced by Du Pont as a coproduct in the manufacture of Qiana fiber. Du Pont subsequently sold the product to Bayer. In the 1990s MDA is hydrogenated by Air Products for Bayer (see Amines, aromatic-methylenedianiline). Commercial HMDI is a mixture of three stereoisomers. Semicommercial aUphatic diisocyanates include /n j -cyclohexane-l,4-diisocyanate (CHDI) and y -tetramethylxylylene diisocyanate (TMXDI). A coproduct in the production of TMXDI is y -isopropenyl-a,a-dimethylben2yl isocyanate (TMI), which can be copolymerized with other olefins to give aUphatic polyisocyanates. 

Qiana fibers have a high glass transition temperature (135°C, as compared to 90"C for nylon-6,6), which assures that the polymer will remain in the glassy state during fabric laundering and resist wrinkles and creases. 

In the 1970s, DuPont commercialized a silk-like Qiana fiber based on poly(bis[4-aminocy-clohexyljmethane dodecaneamide) or PACM,12 [87]. The base polymer is synthesized from bis(4-aminocyclohexyl)methane and dodecanedioic acid. The diamine exists in three isomeric forms trans-trans, cis-trans, and cis-cis. Its content of trans-trans isomer can be controlled by specific catalysts during its preparation. A normal diamine intermediate contained 51% trans-trans, 40% cis-trans, and 9% cis-cis isomers [88,89]. For Qiana fiber, the trans-trans content was about 70%. The polymer had a melt temperature of 290°C. 

Qiana Fiber from rrans-diamino dicyclohexyl methane + dodecane dicarboxylic acid Du Pont, U.S. 

Qiana, introduced by Du Pont in 1968 but later withdrawn from the market, was made from bis(4-aminocyclohexyl)methane and dodecanedioic acid. This diamine exists in several cis—trans and trans—trans isomeric forms that influence fiber properties such as shrinkage. The product offered silk-like hand and luster, dimensional stabiUty, and wrinkle resistance similar to polyester. The yam melted at 280°C, had a high wet glass-transition temperature of - 85° C and a density of 1.03 g/cm, the last was lower than that of nylon-6 and nylon-6,6. Qiana requited a carrier for effective dyeing (see Dye carriers). 

The polyamide copolymer of dodecanoic acid with methylenedi(cyclohexylamine) (MDCHA, PACM) was sold as continuous filament yam fiber under the tradename QIANA. As late as 1981, over 145,000 t was produced using high percentages, typically 80%, of trans, trans MDCHA isomer. The low melting raffinate coproduct left after t,t isomer separation by fractional crystallisation was phosgenated to produce a Hquid aUphatic diisocyanate marketed by Du Pont as Hylene W. Upon terrnination of their QIANA commitment, Du Pont sold the urethane intermediate product rights to Mobay, who now markets the 20% trans, trans—50% cis, trans—30% cis, cis diisocyanate isomer mixture as Desmodur W. In addition to its use in polyamides and as an isocyanate precursor, methylenedi (cyclohexyl amine) is used directiy as an epoxy curative. The Hquid diamine mixture identified historically as PACM-20 is marketed as AMICURE PACM by Anchor Chemical for performance epoxies. 

Qiaiia, a polyamide fiber with a silky texture, has the following structure. What are the monomer units used in the synthesis of Qiana ... 

Qiana [Du Pont]. TM for a nylon-type synthetic fiber with properties similar to silk. 

Research and development in fluid jet technology led to its widespread use in film and web processing, mixers, reactors, and fiber processing. Applications to fibers alone includes Taslan bulked yams, jet piddlers, draw-jets, interlaced yams, bulk-crimped carpet fibers (BCF), and spunbonded products such as Reemay polyester, Typar polypropylene (PP), and Tyvek olefins. New fibers also were introduced Nomex aramid, especially suited for high-temperature applications Lycra spandex, an elastic textile yam Qiana nylon, with a silklike appearance and Kevlar aramid, used in products ranging from tires to bullet-resistant vests. 

Polymers have also been prepared from cyclic amines such as piperazine and bis(p-aminocyclohex-yl) methane. The latter amine is condensed with decanedioic acid to produce the silklike fiber Qiana (Du Pont). 

Qiana Du Pont Polyamide fiber firom bis(p-aminocyclohexyl)methane and dodecanedioic acid... 

Qiana /ke-m- o/ (Trade name for silk like fiber material) Fiber from trans-diamino dicyclohexyl methane -I-dodecane dicarboxylic acid, manufactured by DuPont, U.S. New fibers should help the synthetics to capture an even bi er piece of the total. One of them is Qiana, introduced, after 20 years of experimentation, by E. I. du Pont de Nemours and Company, the largest U.S. producer of synthetic fibers. The new fiber has the appearance and feel of silk but has wrinkle-resistant and wash-and-wear properties that are as good or better than... 

Several other polyamides have been introduced for use as fibers in specialty applications where certain combinations of properties are desired. The major specialty nylons include Qiana, nylon 4, nylon 11, nylon 6,10, and biconstituent nylon-polyester. Their particular characteristics are outlined below. 

Qiana is a trade name (duPont) for the luxury nylon fiber formed through step growth polymerization of trans.trans-di(4-aminocvclohexvn methane and a dibasic acid having 8-12 carbon atoms ... 

Qiana has a tenacity of 3-3.5 g/d (27-32 g/tex) and an elongation at break of 20%-30%. It is reported to recover from strain better than nylon 6,6 or polyester. It has a specific gravity of 1.03 and a moisture regain of 2%2.5% which are much lower values than nylon 6 or 6,6. Qiana melts at 275°C and is stable 15) to 185°C. The cross section of the fiber is tri-lobal (Figure 6-3). It shows good chemical stability and is readily dye-able to fast colors. The excellent aesthetic qualities and drapability of Qiana have contributed greatly to its success. 

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