Fiber tensile properties

Mechanical properties of the blends were investigated in fiber form. The as-spun fiber tensile properties are summarized as shown in Table 4. These fibers were further drawn at elevated temperatures at various draw ratios. These drawn fibers were stronger than the as-spun fibers. Table 5 illustrates the effects of temperature and draw-ratio on the fiber properties. Drawing at 400 °C at a ratio... 

Some work has been undertaken towards the optimization of the AN/VBr precursor. The work extends into all four relevant areas, viz. polymerization, spinning, stabilization and carbonization. Although probably far from a complete optimization, considerable improvement has been obtained with regard to the key factors — stabilization time, and carbon fiber tensile properties — as compared to the screening conditions . 

FIGURE 10.84 Structure and fiber formation influence of structural units on fiber tensile properties. 

The structure of the fiber formed in the spin bath strongly influences the tensile properties of the final product. Knudsen [268] has demonstrated that the influence of the coagulation bath variables on the fiber tensile properties can be rationalized in terms of the uncollapsed fiber structure. As the spin-bath temperature is lowered and a denser and finer structure is... 

Very recently, Perez [23] obtained melt-spxm fibers of PP reinforced with different contents of submicron-sized quartz particles. Remarkable improvements in the fibers tensile properties were foxmd as a result of the introduction of quartz particles. Particularly, significantly higher values of strain at failure were observed for the composite fibers in comparison with neat PP fibers. 

Although many attempts have been made to produce a more crystalhne polymer with improved fiber tensile properties, success has been limited and, invariably, the teehniques used would not be commercially viable. Similarly, attempts by Allen, Ward and Bashir [162] to produce a high modulus PAN fiber (55GPa) by gel spinning, were not sueeessful and it was concluded that an ultrahigh modulus PAN fiber eaimot be made by any teehnique, due to the intrinsic chain properties, where the strong intramolecular nitrile repulsions cause the PAN to adopt a semi-extended rod-like conformation, thereby not allowing the chain to unravel from its semi-extended form. 

RELATION OF CARBON FIBER TENSILE PROPERTIES TO PROCESS CONDITIONS... 

PET (100-90)/LCP (0-10) (Unitika LC3000) TSE at 290 °C/DSC/SEM/capillary rheometry/WAXD/NMR/fiber tensile properties/dibutyltin dilaurate catalyst (0-0.1 wt%) Hong et al. 1997... 

A fiber is selected for a specific product based on its ability to be processed and converted into the desired finished device and its potential for assisting the product in effectively performing the required function. There are six primary physical characteristics that are considered essential for this purpose. These are fiber size and shape fiber tensile properties fiber bending properties fiber thermal transitions and heat setting properties fiber surface energetics and fiber moisture absorption... 

The stress-strain curve showed good linearity over a considerable strain, but did not show a typical yield point characteristic of polymer films and macrofibers. An elastic modulus of 45 MPa was determined for the PEO nanofibers (Tan et al. 2005a). A similar approach based on using AFM for assessing the single-fiber tensile properties of PAN was reported by Buer et al. (2001). 

Table 3. Fiber Tensile Properties of Aromatic Poly(anhydride)s as a Function of Draw Ratio...

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