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Preparation and Investigation of Ziegler-natta Catalyst with Nano MoS2 Support in UHMWPE Synthesis

Amini, Majed | 2017

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 49654 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Ramazani Saadat Abad, Ahmad
  7. Abstract:
  8. Ultra high molecular weight polyethylene has attracted the attention of numerous researchers and industries. This polymer due to its strong properties can be used in advanced military industries, medical engineering and cases in which high strength and high abrasion resistance is required. Present study aims to fabricate UHMWPE/Molybdenum disulfide composites, using in-situ polymerization. Before carrying out the polymerization process, nanoparticles of molybdenum disulfide underwent various processes such as oxidation, pickling, ultrasonic and thermal shock, in order to increase the interlayer distance and creating functional groups on the surface, then various analyzes, such as XRD, FESEM, TEM, Raman, FTIR, etc. were performed in order to confirm the created functional groups and increased interlayer distance. in order to perform polymerization, Ziegler-Natta catalytic system with molybdenum disulfide and magnesium ethoxide as supports were used. Titanium tetrachloride (TiCl4) was used as catalyst and tri-isobutyl aluminum (TiBA) as co-catalyst. Since the activity of Ziegler-Natta catalyst system is highly sensitive to weather, all the stages of catalyst and nanocomposite fabrication were conducted under inert argon gas atmosphere. In order to fabricate nanocomposites with different percentages of filler, all the process parameters were constant but time. SEM images show the efficient distribution of nanoparticles in the polyethylene matrix. A significant increase of the mechanical properties such as modulus and yield stress confirmed proper distribution and effective interaction between nanoparticles and polyethylene. Thermal properties of fabricated nanocomposites analyzed by TGA and DSC tests. The results indicate the increased crystallinity, melting temperature and enhanced thermal stability of samples. Mechanical tests show a significant increase in modulus and tensile strength of nanocomposite containing filler compared to pure polymer. In order to evaluate the abrasion properties of samples, abrasion of pin on disk analysis was conducted and results showed the increased abrasion resistance of samples
  9. Keywords:
  10. Nanocomposite ; In-situ Polymerization ; Ultra High Molecular Weigh Polyethylene (UHMWPE) ; Ziegler-Natta Catalyst ; Molybdenum Sulfur

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