Tenacity poly fibers

Poly(a, -dimethyl-j3-thiopropiolactone) has been melt-spun at 185°C to give a fiber which, after drawing, had a tenacity of 1.4 g/den. (polyethylene terephthalate, 4-7 g/den.) and an initial modulus of 12 g/den. (30-130 g/den.) (16). Tensile recovery at 10% elongation was 80%. No information is available about poly (thiol esters) with higher melting points, such as poly(hexamethylene dithiolterephthalate). 

Poly[2,2 -(m-phenylene)-5,5 -bisbenzimidazole] was chosen as the most promising candidate for further development as a fibrous material. Under the terms of an Air Force contract, DuPont was able to spin fibers from both dimethyl-sulfoxide and dimethylacetamide solutions to form relatively strong, thermally stable fibers. In 1963, an Air Force contract was awarded to Celanese Research Co. for the development of a manufacturing process for the scale-up of PBI production. PBI fiber of tenacities 0.31-0.44 N/tex (3.5-5.0 gfiden) were produced in sufficient quantity for large-scale evaluation. The fiber was discovered to have... 

Poly(tetramethylenediamine-co-adipic acid), nylon-4,6 [24936-71-8], polymer introduced as Stanyl by Dutch State Mines is spim into a high-temperature-resistant, high-tenacity filament yam, Stanylenka 460 HRST, by Akzo Nobel Faser AG in Wuppertal, Germany. Stanylenka is intended for industrial applications including tire cord and automotive airbags because of its enhanced heat capacity, improved chemical resistance, better dimentional stability, and higher modulus than nylon-6,6 (176). The fiber melts at 285°C and has a density of 1.18 g/cm . 

Poly(bis-[p-aminocyclohexyl]methane-co-dodecanedioic acid), PACM-12 [24936-74-1], introduced by DuPont as Qiana in 1968 was later withdrawn from the market. This diamine exists in several cis-trans and trans-trans isomeric forms that influence fiber properties, such as shrinkage and tenacity. The product offered silk-like hand and luster, dimensional stability, 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 required a carrier for elFective dyeing. 

Figure 8.1. Overview of high performance fibers mechanical properties. PET = poly(ethylene terephthal-ate), UHMWPE = ultra high molecular weight polyethylene, PBO = poly(benzoxazole), M5 = PIPD or poly[di-imidazo-pyridinylene-(dihydroxy phenylene)]. The p-aramids included in the area are Kevlar, Twaron, Technora and SVM (Armos, Rusar) fibers. The latter fiber tjipe accounts for the high mod-ulus/high tenacity area of aramids (Adapted from ref. [6]). For chemical structures see Scheme 8.1...

Figure 2 shows the correlation between the fiber tenacity of poly(pheny1-1,4-phenylene terephthalate) and melt viscosity, which is a measure of the polymer molecular weight. Melt-spun fibers were heat-treated in an oven at 300 C and at 320°C for various times, removed and chopped, and then compression molded into sample disks for use in determining the melt viscosity of the remelted fibers with a Rheometrics Mechanical Spectrometer in the... 

Fig. 2. Correlation of fiber tenacity and melt viscosity of poly(phenyl-1,4-phenylene terephthalate).

Aromatic polyhydrazides are well known from the work of Frazer, Wallenberger and Sweeny (1,2) as precursors to poly-1,3,4-oxadiazoles. Poly-amide-hydrazides have been described in detail by Black, Preston, and coworkers (3,4,5) and by Culbertson and Murphy (6). High tenacity, high modulus fibers have been made from poly(terephthalie hydrazide)(7) and from polyamide-hydrazides with ordered structures (5). 

In this subsection, on-line studies of fibers and films will be discussed concentrating on applications to poly(ethylene terephthalate) (PET) and polypropyene (PP) by the work of Chase [17], Van Wijk et al. [72], and Cakmak and Pelletier (unpublished work). As in other process applications, the motivation for this work is to move to on-line analysis so that real-time monitoring of a process in order to maximize certain properties is possible. In the fiber industry, some of the important fiber properties are breaking tenacity, elongation at break, level of shrinkage, or suitability for dye uptake. 

There are many polymers with high-temperature resistant fibers, most of them with textile properties (low tenacity, high elongation) (see Table 17.7). Their application is in insulation, hot gas filtration, and suchlike. Large products are meta-meta aramid (Nomex, Teijin-Conex) and polybenzimidazole (PBI). Smaller products are poly(phenylene sulfide) (PPS), several aromatic polyketones (for example poly(ether ether ketone), PEEK) and aromatic polysulfones see Reference 9, Chapters 8 and 9. 

High speed spinning Flat filaments fine denier filaments (< 1.7 dtex) bicomponent filaments (conjugated and blended filaments) spun-dyed filaments high tenacity filaments (> 50 cN/tex) elastomeric filaments textured yarns UDY-DTY, FDY-ATY, POY-DTY, POY-ATY blow texturing staple fiber (higher titer) poly filaments (BCF) (200-1600 dtex)... 

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