Dissertation > Excellent graduate degree dissertation topics show

Study on Hollow Porous Polypropylene Fiber with the Separability

Author: HanXiao
Tutor: XuDeZeng
School: Dalian University of Technology
Course: Materials Processing Engineering
Keywords: polypropylene hollow fiber porous separability liquidity toughness
CLC: TQ342.62
Type: Master's thesis
Year: 2010
Downloads: 12
Quote: 0
Read: Download Dissertation

Abstract


Polypropylene hollow fibers have the properties of light weight and keeping warm. Withthe continuous development of science technology and people’s demand for life quality,people have focused on the problem of biomedical and environment pollution. Usingpolypropylene fibers as clothing materials can’t meet the people’s demand, polypropylenehollow porous fibers which have the separation property have arised people’s attention, and italso has been the hot topic of polypropylene fiber research. Polypropylene hollow porousfibers are playing a leading role in the ocean resources development, high efficient ofchemical separation process, artificial hearts application and comprehensive utilization ofindustrial waste etc.Polypropylene is modified based on the method of melting spinning-stretch, and it isblended with β nucleating agent. The dual blend is spinned into hollow fibers through thehollow spinneret. Through the stretch treatment, polypropylene fibers’ lamella crystalstructure which is parallel and perpendicular to the extrusion direction can be stretched intomicropore structure. Polypropylene hollow porous fibers with separation property areprepared by this method, and it can have the new morphology an structure. Polypropylenefibers can have new morphology an structure through this method.The methods and the results of research are as follows:(1) The blend materials of PP and β nucleating agent are prepared by using direct moltenblending method, and its crystallization process is charactered.(2) The composite materials of PP and β nucleating agent are treated by melting, castingand cutting, and its rheology is characterd to determine the spinning process parameters.(3) The preparation of PP and β nucleating agent blending fibers: PP is blended with βnucleating agent in different proportion, and the blend is spinned into hollow fibers by usinghollow spinneret. The process conditions and formula of fibers preparation is researched(4) The blending hollow fibers are stretched, and the stretch process conditions are alsoanalyzed. (5) The hollowness and microstructure of polypropylene hollow porous fibers areobserved and characrtered, and its mechanical properties are also analyzed.(6) The blending fibers are tested and analyzed by using DMA in certain frequencies, andits dynamic mechanical properties are also analyzed.(7) The blending fibers are tested and analyzed by using TGA, and its thermalgravimetryproperties are also analyzed.(8) The hollow porous fibers separate dye and test the light transmittance of filtrate.The research results show that: β nucleating agent can increase the crystallization rateand make the crystal grain more fine. The toughness and ductility of polypropylene areimproved because of the crystallinity increasing which results from the β nucleating agent.Because the crystallinity increases, the polypropylene spherulites are destroyed and thespherulite density becomes lower. The amorphous area can form the micropore structureeasily after the hollow fibers are stretched. The micropore structure not only have the effect offiltration and separation, but also can improve the toughness of blending fibers further. But itsmechanical property will decrease. β nucleating agent results in the blend appears the shearthinning phenomenon, the non-newtonian index n is less than1,and the blend is thepseudoplastic fluid. The blend viscosity decreases and its fluidity become more fine with theincrease of the content of β nucleating agent.

Related Dissertations

  1. Experimental Study of Porous Composite Materials on the Base of Recycled Concrete Powder-Cement,TU528
  2. Gel - Foam Preparation of porous alumina insulation materials,TQ174.1
  3. Investigation of Preparation and Properties of Ordered Porous TiO2,TB383.2
  4. The Modification of Polypropylene by Melt Grafting and Blending and Its Fatigue Resistance,TQ325.14
  5. Process Safety Research of Polypropylene Plant,TQ325.14
  6. Study on Liquid Crystalline Polymers as a New β-crystal Nucleating Agent to Induce Crystallization Behavior of PP,TQ325.14
  7. Study on Sulfonation Surface Treatment of Plasma Alkali Secondary Battery Separator,TM910.5
  8. Preparation and Performances of Polypropylene/LDHs Composites,TB332
  9. Effects of Environments on Fracture Toughness and Fracture Behavior of 304 Stainless Steel,TG142.71
  10. Study on Liquid Crystalline Polysiloxanes as β Nucleator to Induce Crystallization Behavior of PP,TQ325.14
  11. Study on Liquid Crystalline Polyacrylates as a New Nucleator to Induce Crystallization Behavior of PP,TQ325.14
  12. The Dispersion and Its Evaluation of Fiber in the Theroplastic Composites by Wet Process,TB332
  13. Preparation and Characterization of Stainless Steel Hollow Fiber Support Membrane,TB383.2
  14. Research of Material Mechanical Properties by Small Punch Testing,TG115.5
  15. Happiness Course and Practice Based on Psychological Toughness,B844.2
  16. Nanoimprint Using Porous Alumina Template,TB383.1
  17. The Effect of Heterogeneous Microstructure on the Room Temperature Mechanical Properties in Bulk Metallic Glass,TG139.8
  18. The Research of Probabilistic Fracture Mechanics Analysis of Reactor Pressure Vessel with Defects under the Pressurized Thermal Shock Transient,TL351.6
  19. The Impact of Macro-liquidity on Equity Price in Secondary Market: An Empirical Research Based on Chinese Securities Market,F832.51;F224
  20. Research on Listed Companies’ Cash Dividend Policy in China,F276.6
  21. Studies on the Liquidity Risk Management of Chinese Commercial Banks in the Background of Post Financial Crisis,F832.33

CLC: > Industrial Technology > Chemical Industry > The chemical fiber industry > Synthetic fiber > Polyolefin fibers > Polypropylene fibers ( PP)
© 2012 www.DissertationTopic.Net  Mobile