Production and characterization of polyacrylonitryl based nanocomposite fiber

Polyacrylonitrile (PAN) is a thermoplastic polymer produced via polymerization of acrylonitrile monomers. Thanks to the polar acrylonitrile groups, many strong secondary interactions are found in its structure and those lead to superior properties such as good mechanical properties and strong thermal strength. Because of so called superior properties, polyacrylonitrile has become a highly demanding polymer by the fiber industry. PAN fibers are produced by solution spinning technique in the industrial scale. PAN solution which dissolves in appropriate solvent is released from fiber spinning system in the form of gels and after that gels are solidified in the precipitation bath. The fibers obtained by this method are generally in the micron size. In addition to microfibers PAN is widely used for nanofiber production. Electro-spinning method is one of the most effective methods used for nanofiber production. As in traditional PAN fiber production, solution spinning technique is used in electro spinning method. The fibers are obtained by using electrical force from the polymer solution that has proper viscosity. Besides PAN nanofibers, nanocomposite PAN fibers can also be produced. Both PAN and nanocomposite PAN fibers have a wide range of applications such as drug release, tissue engineering, filtration, fireproof outerwear, carpet and curtain fabric. Halloysites are nano-sized and have tubular structure. These nanotubes obtained from nature were first used by Berthier in 1826 in history. Pristine halloysite nanotubes are usually white in color and rock- shaped materials can easily be powdered. Halloysite nanotubes have many advantages such as easy accessibility, high functionality, high mechanical strength. Thanks to these properties, it can be used as catalyst, adsorbent and polymer filling material. Compared to other clay-derived nanofiller materials, the halloysite nanotubes have more hydrophobic structure due to the relatively low hydroxyl group content on the surface. Therefore, it can be dispersed easily in non-polar polymers. It is an ideal filler material for many different polymers due to its high nanoparticle and high aspect ratio. Even in the addition of such low amounts of 5% modulus, hardness, impact resistance of polymers is relatively increased. It also prevents heat and mass transport due to its nanotube structure and it is used as a flame retardant in nanocomposite structure. In this study, nanocomposite PAN fibers containing halloysite nanotubes were produced by using electro-spinning method. First, an optimization study was carried out by PAN solution. After this study, different concentrations of solutions were prepared and nanocomposite fibers were produced. Morphological analysis of the nanocomposite fibers was carried out by scanning electron microscopy (FESEM), and thermal properties were characterized by thermal gravimetric analysis (TGA).