Vectran® fibers

Data given in Table 5.7 shows the effect of polymer composition and heat treatment on the tensile properties of HBA/HNA fibers. The copolymers with approximately a molar ratio of 3/1 of HBA/HNA seem to give the best balance of properties after heat treatment. The properties of a representative Vectran fibers are shown in Table 5.8. 

UENO-LCP (Ueno Fine Chem.) VECTRAN (Fiber)(Kuraray)... 

This periodicity of about 500 nm has been reported for banded textures observed in both the thermotropic copolyesters and the aramids [407, 430, 439-445]. The lateral banded textures exhibited by some of the thermotropes and the pleated sheet textures exhibited by some of the aramids are observed only in materials which have a poorer degree of molecular orientation. The more highly oriented thermotropic and lyotropic fibers do not exhibit these textures. For instance, heat treated Vectran fibers do not exhibit any lateral banding. Likewise, Kevlar 149 exhibits a higher tensile modulus than Kevlar 49 [448], nearly 80-90% of theoretical predicted values. This is consistent with increased crystallinity and crystallite size, and without a pleated sheet structure. The relationship of the optical... 

Fig. 5.110 The in situ structure of a spun Vectran fiber is shown in a TEM micrograph of an ultrathin, longitudinal section. The orientation is shown by the microdiffraction pattern inset.

Fig. 5.113 FESEM images show the internal texture in peeled-back highly oriented (A) Vectran as spun fiber, (B) Vectran heat treated fiber and (C) Kevlar fiber which also exhibits a fibrillar texture. Kink bands are also observed in a Vectran fiber (D). (From Sawyer et al. [435] reproduced with permission.)...

Fig. 5.114 Peeled-back Vectran fibers are shown in a top down view in the STM of a region 500 run in the x and y axes and a maximum z axis range of 50 ran. The fibrillar texture and local disorder is observed. A kink band is observed as are clear discontinuities across individual microfibrils and damaged microfibrils within the kink band. (From Sawyer et al [435] reproduced with permission.)...

LC polyester fibers have high strength and stiffness and are lightweight. Fabrics of LC polyester fibers (such as Vectran fibers) have been used as ballistic garments, helmets, and military flak jackets. Excellent cut/tear resistance and thermal insulation also make LC polyesters fibers desirable for protective gloves and clothing. 

The DSC curve of Vectran fiber, which is a random copolymer of p-hydroxy-benzoic acid (HBA), and 2-hydroxy-6-naphthoic acid (FINA), shows a very broad glass transition at -100 °C, and an extremely broad melting peak... 

Trade names - Ardel U-polymer Vectran (fiber) ... 

Zeng J, Netravali AN. XeCl excimer laser treatment of Vectran fibers. J Adhes Sci Technol 2006 20 387-409. 

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