Copolymers fibers

The copolymer fiber shows a high degree of drawabiUty. The spun fibers of the copolymer were highly drawn over a wide range of conditions to produce fibers with tensile properties comparable to PPT fibers spun from Hquid crystalline dopes. There is a strong correlation between draw ratio and tenacity. Typical tenacity and tensile modulus values of 2.2 N/tex (25 gf/den) and 50 N/tex (570 gf/den), respectively, have been reported for Technora fiber (8). 

Combination techniques such as microscopy—ftir and pyrolysis—ir have helped solve some particularly difficult separations and complex identifications. Microscopy—ftir has been used to determine the composition of copolymer fibers (22) polyacrylonitrile, methyl acrylate, and a dye-receptive organic sulfonate trimer have been identified in acryHc fiber. Both normal and grazing angle modes can be used to identify components (23). Pyrolysis—ir has been used to study polymer decomposition (24) and to determine the degree of cross-linking of sulfonated divinylbenzene—styrene copolymer (25) and ethylene or propylene levels and ratios in ethylene—propylene copolymers (26). 

Young s modulus of the block copolymer fibers compared favorably with that of the physical blends as shown in Table 6, and in general they follow the linear rule of mixtures. The modulus data suggested that one does not need very large PBZT molecules to have the reinforcing efficiency. From the tensile data, one clear trend is that the tensile strength of the block copolymer system is much... 

Nevertheless, the migration of water into the fiber is sufficient to produce the above-mentioned plasticization effect. The chain mobility is inaeased, as indicated by a decrease of the glass transition temperature by 35—50 C This is a very fortunate fact, because dyeing of the fibers is possible only above the Tg, where the increased polymer segment mobility permits dye diffusion within the fiber. For the commercial polyacrylonitrile copolymer fibers, the Tg in water hes in the r on of= 80 so that dyeing at, or slightly below, the boiling point of water becomes... 

Recently, we reported (1, 2) a new class of high strength/ high modulus fibers prepared from all-p-phenylene oxadiazole/ N-methyl hydrazide copolymers. Oxadiazole homopolymers and fibers had been described earlier by Iwakura (3), Imai (4), and Frazer (5). All-p-phenylene oxadiazole/N-methyl hydrazide copolymer fibers were shown by us to give tire cord with excellent end use performance including good fatigue characteristics. In concurrent... 

Yoon, K.J., Woo, J.H., Seo, Y.S., 2003. Formaldehyde free cross-linking agents based on maleic anhydride copolymers. Fibers Polym. 4, 182-187. 

Py-GC can therefore be used as an effective means of determining the chemical composition of man-made homopolymer and copolymer fibers, natural fibers, fiber blends, or partly degraded fibers. Pyrograms of polyester, acrylic, and cotton fibers show how these fibers can readily be identified (Figure 8.11). 

Which of the following fibers are synthetic polymers based on cellulose a) acetate b) Kevlar c) Mylar d) polyester e) rayon. Sydney s copolymer fiber combines the incredible strength of cotton with the beauty and versatility of silk. If you actually made a random copolymer of glucose and an amino acid, why wouldn t it be as strong as Sydney s copolymer ... 

Ethylene/tetrafluoroethylene copolymer Nylon 46 Polycarbonate Polyphenylene sulfide resin Polytetrafluoroethylene Vinyl chloride/vinyl acetate copolymer fiber, industrial applies. 

Polytri methylene terephthalate Vinylidene chloride/methyl acrylate copolymer fiber, natural food Wheat (Triticum vulgare) bran fiber, natural pharmaceuticals Wheat (Triticum vulgare) bran fiber, natural supplements Wheat (Triticum vulgare) bran fiber, nonwoven fabrics Polyethylene terephthalate... 

Meng, Q.H. and Hu, J.L. (2008) Study on poly (e-caprolactone)-based shape memory copolymer fiber prepared by bulk polymerization and melt spinning. Polymers for Advanced Technologies, 19, 131-136. 

Fig. 1 Preparation methods for poly[(/J)-3-hydroxybutyrate], P(3HB), and its copolymer fibers. (Reprinted with permission from Iwata 2(X)5. Copyright 2005, Witey-VCH Veriag GmbH Co.)...

The copolymer fibers exhibited high elasticity and resilience, suggesting that the [48] scaffolds could withstand repeated cyclic loading, as occurs in the vascular system. 

The melt-spun monofilament fibers from this triblock material were achieved at temperatures about 10-40°C above the corresponding melting temperatures of the copolymers. An in vivo implantation study of a triblock copolymer fiber (of 5/5/90 feed ratio) in rat up to 240 days showed that the monofilament fibers were morphologically intact at 120 days but fragmented at 150 days. Complete mass absorption was achieved at 240 days in rats which is consistent with the reported complete mass absorption for pure PDS sutures. The tissue reaction observed was typical... 

Other unusual additives include oxetanes, vinylic macromono-mers, silicon carbide, superconductive carbon blacks, silver-coated fly ash, metal oxides, Tb for green emission, antibacterial agents, and organic-inorganic hybrid copolymer fibers. In an interesting reversal, transition element acetylacetonate salts were decomposed in a PDMS matrix to give membranes with catalytic activity. ... 

Swart, M. Olsson, R. T. Hedenqvist, M. S. Mallon, P. E., Organic-Inorganic Hybrid Copolymer Fibers and Their Use in Sihcone Laminate Composites. Polym. Eng. Sd. 2010,50, 2143-2152. 

Kalra V, Mendez S, Lee JH, Nguyen H, Marquez M, Joo YG (2006) Confined assembly in coaxially electrospun block copolymer fibers. Adv Mater 18 3299-3303... 

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