Dissertation > Excellent graduate degree dissertation topics show

Research on a Emulsion-Based Spherical Self-supported Ziegler-Natta Catalyst for Polymerization of Propylene and Ethylene

Author: ZhaoLiNa
Tutor: JiangTao
School: Tianjin University of Science and Technology
Course: Applied Chemistry
Keywords: Ziegler-Natta catalyst morphology emulsion propylene ethylene
CLC: TQ426
Type: Master's thesis
Year: 2012
Downloads: 2
Quote: 0
Read: Download Dissertation

Abstract


This paper was established in the research on the spherical Ti-based Ziegler-Natta catalysts. The research was aimed to prepare novel spherical Ti-based Ziegler-Natta catalyst for propylene or ethylene polymerization via emulsion technique. The effects of the components and their amounts as well as the conditions during the preparation of the catalyst on catalyst average particle size(APS), particle size distribution(PSD) and morphology were investigated in order to control the APS. PSD and morphology of the catalyst and the polymer.The effects of the amount and injection method of the emulsifier, adding ternpreture and time of the Mg-Complex. mixing speed, and BuCl on catalyst morphology. APS, and PSD were studied. Effects influencing the polymerization performances were also investigated:alkylaluminu/Ti molar ratio, external donors/Ti molar ratio, polymeric temperature and pressure. The ester, elements, APS, PSD, morphology, and structure of the catalysts were characterized by GC, GC/MS, XRD, SEM, BET, Coulter counter analysis, and UV. The polymer was characterized by SEM and DSC.Investigative results indicated that the morphology of catalyst was mainly determined by the amount and injection method of the emulsifier.And then APS and PSD were mainly determined by the adding tempreture and mixing speed. One optimal method produced spherical catalyst with less fines and narrower PSD was after addtion of Mg-Complex to TiCl4at-25℃, then polyester(2.2wt%) and T803B were added, finally the temperature was increased in a controled way. During all the preparation the mixing speed kept200rpm.Results show that the polymerization activity of the catalyst with low surface area was nevertheless high. The polyolefins replicated the shape and PSD of the catalyst. The low surface had few effects on the kinetics of catalyst system; activity for polymerazation firstly increased then decreased when polymeric temperature increased; activity for polymerazation increased when polymeric pressure increased. The effects of alkylaluminu/Ti molar ratio and external donors/Ti molar ratio on the catalyst’s performance accord with the conventional Ziegler-Natta Catalyst. The highest activity obtained with different alkylaluminu/Ti molar ratio based on the characteristic structure of the alkylaluminu in propylene polymerization. And the molar ratio increased with increasing alkyl group size in the cocatalyst. Furthermore the catalyst showed a higher stereospeeificity responsibility in propylene polymerization with CHMDMS rather than DCPDMS.

Related Dissertations

  1. Tongue Feature Extraction and Research of Fusion Classification,TP391.41
  2. Studies on Leaf Epidermal and Pollen Micro-morphology and Geographical Distribution of the Genus Euonymus of Henan,Q944
  3. Sagitta Morephology, Distribution, Biology and Stock Assessment of Four Prlagic Species in the Mouth of Beibu Gulf,S932.4
  4. Preparation and Characteration of Composite Microspheres with Dual-, Triple- Responsive Properties,O631.3
  5. The Evolvement of Quartzs and Phytoliths in Basalt-Derived Chronosequence Soils in Tropics Area of China,S153
  6. Radiation Transfer Characteristics and Radiation Use Efficiency of Rice,S511
  7. Effects of Processing Conditions and Frozen on Emulsifying Properties of Pork Myofibrillar Proteins,TS251.1
  8. Effect of Flaxseed Gum on Pasting and Retrogradation of Corn Starch and Application on Flaxseed Gum on Emulsion-Type Sausage,TS231
  9. Cross-Talk between Ethylene and Heme-Heme Oxygenase Signal System in Primary Root Growth Inhibition of Etiolated Tomato Seedlings,S641.2
  10. Genotypic Variation for Root Morpha and Potassium Accumulation in Maize Inbred Lines under Potassium Stress Condition,S513
  11. Water in oil emulsion of water hit the harmonic the demulsification dynamics analysis and its mechanism,X703
  12. Implanted in mouse endometrium during early morphological and Galectin-3, expression of integrin α4,R321
  13. Special morphology precursor synthesis route inorganic oxide,TB383.1
  14. Study on Film Morphology, Surface Properties and Film Formation Mechanism of Amino Silicone Oils,TS195.23
  15. Study on the Preparation and Applications of Inhibitor for Coal Dust,TD714
  16. Synthesis of Polymer Containing Hydroxamic Acids Group by Inverse Emulsion Polymerization and Its Application,X703.5
  17. Synthesis, Characterization and Properties of One-dimensional Silicon Carbide Nanomaterials,TB383.1
  18. An Analysis of Image Segmentation Based on Otsu Method and Mathematic Morphology,TP391.41
  19. The Synthesis and Characteristic of Metal Sulfide or Oxide (M=Fe, Co, Ni) Nanostructures,TB383.1
  20. Cultural factors on the impact of foreign language teaching grammar,H195
  21. Synthesis and Application of Biomedical Magnetic Nanoparticles,TB383.1

CLC: > Industrial Technology > Chemical Industry > Reagents and the production of pure chemicals > Catalyst ( catalyst )
© 2012 www.DissertationTopic.Net  Mobile