علوم و تکنولوژی پلیمر (Jun 2014)
VVertical Electrospinning of UHMWPE/ZnO Nanocomposite Fibers at High Temperature
Abstract
UHMWPE, as a thermoplastic polymer and especially in the form of high performance fiber, has attracted much interest due to its exceptional tribological and mechanical properties. In this work, electrospinning process, known as a versatile, low cost, highly efficient and suitable technique for continuous production of fine fibers in micron or nanometer scale is employed to fabricate the UHMWPE/ZnO nanocomposite fibers. Electrospinning of UHMWPE has some inherently serious problems and limitations, due to its poor solubility in common solvents and low electrical conductivity of its solution. The most important issue is the necessity of maintaining the system temperature sufficiently high to prevent temperature depression and solution gelation during spinning. Fabrication of UHMWPE/ZnO nanocomposite fibers, containing 2.5, 5 and 7.5 wt% of ZnO nanoparticle, was carried out by self-modified vertical electrospinning at high temperature. An electrospinning system was first equipped with an infrared emitter (IR heaters) and then the conditions for fabrication of bead-free uniform UHMWPE fibers with an average diameter of 1.8±0.25mm were implemented. Under the acquired conditions, uniform and bead-free UHMWPE/ZnO nanocomposite fibers containing various percentages of ZnO nanoparticles were also successfully produced. UHMWPE/ZnO nanocomposite fibers exhibited much higher average diameter proportional to added percentage of nanoparticles. The morphology and the quality of nanoparticles dispersion within nanocomposite fibers were evaluated using field emission scanning electron microscopy (FESEM) equipped with EDAX mapping spectra. The results showed a well dispersed morphology, which was attributed to good compatibility between the ZnO nanoparticles, solvent and UHMWPE matrix.
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