Dissertation > Excellent graduate degree dissertation topics show

Thermal Conductivity and Its Characterization of PP/Al（OH）3/Mg（OH）2 Composites

Author: QiuYuLin
Tutor: LiangJiZhao
School: South China University of Technology
Course: Chemical Process Equipment
Keywords: polypropylene composites thermal conductivity coefficience thermal conductivity model aluminium hydroxide magnesium hydroxide
CLC: TB332
Type: Master's thesis
Year: 2010
Downloads: 191
Quote: 2
Read: Download Dissertation

Abstract


Polymer materials with high thermal conductivity has good thermal capability, excellent resistance to chemical corrosion and high temperature performance, which was widely used in the modern industrial and high-tech. However, the vast majority of polymer materials are low thermal conductivity material. Filling polymer with high thermal conductivity filler could obtain high thermal conductivity composites. It is very important to study on heat conduction mechanism of filled thermal conductivity polymer composites.Derived from Fourier’s law, a particle filled polymer composites thermal conductivity theoretical model is based on the law of minimum thermal resistance, the law of the same specific equivalent thermal conductivity and the homogenization theory. The corresponding thermal conductivity prediction formulas are derived. Reference literature experimental data were compared with the thermal conductivity prediction formulas, results show that the calculations and measurements are close to each other, especially in the case of the filler content is low. Preliminary verification of the correctness of the thermal conductivity prediction formulas which derived in this paper.According to the mechanism of heat transfer, the heat transfer in a composite unit is simulated by using a finite element analysis software ANSYS. A 3-dimension model of the composites was structured by finite element software ANSYS, meshed, loaded boundary conditions and solved. According to the simulation results, analysis of the element body’s temperature distribution and heat flux distribution, and obtain thermal conductivity of simulated values of PP/Al(OH)3/Mg(OH)2 composite. The result shows that the composite’s thermal conductivity with the increase of filler content; Thermal conductivity of simulated values of composites which filled with larger size particle are slightly higher.Polypropylene (PP) thermal composites filled with Al(OH)3 and Mg(OH)2 were prepared. The thermal conductivity coefficient of the composites was measured by stable flat measuring instrument NF-7 for thermal conductivity in different testing temperature. The effects on thermal conductivity property of the filler content, testing temperature and filler particle size were analyzed. The results show that the addition of Al(OH)3 and Mg(OH)2 increased thermal conductivity of PP. Thermal conductivity coefficient of PP/Al(OH)3/Mg(OH)2 composites presents a nonlinear increase with an increase of the filler content, a nonlinear increase with an increase of the testing temperature, as well as a nonlinear increase with an increase of the filler diameter. Experimentally measured thermal conductivity coefficient of the PP/Al(OH)3/Mg(OH)2 composites were compared with the predicted. The results show that the predicted and measured values matched well when the filler content is low. Experimentally measured thermal conductivity coefficient of the PP/Al(OH)3/Mg(OH)2 composites were compared with the simulated. We can simulate the thermal conductivity coefficient of composites when filler content is low, thus reducing the cost of experiments and material development.The photos of impact fracture section of specimens are taken to study PP/Al(OH)3/Mg(OH)2 composites’microstructure by using Scanning Electronic Microscopy (SEM). The photos show that small particles more easily dispersed within PP, large particles are more likely to touch each other, accumulate into particle groups. The particles are dispersed more evenly in PP when Filler content is low. The probability of the particles contact with each other and then accumulation into particle groups is increase with increase of the filler content.

Related Dissertations

  1. Study on Characteristics of Contiuous Fiber-Reinforced Metal Matrix Composites under Hypervelocity Projectile Impact,TB332
  2. Preparation and Tribological Properties of TZ3Y20A-SrSO4 Ceramic Matrix Composites,TB332
  3. Reactive Hot-Pressing and Mechanical Properties of （ZrB2-ZrO2）/BN Composites,TB332
  4. Schiff base Synthesis, Characterization and Antibacterial Properties,O641.4
  5. Closed thin-walled beams composite modal damping prediction,TB33
  6. Carbon fiber reinforced epoxy resin surface treatment and interfacial properties of composite materials,TB332
  7. The Modification of Polypropylene by Melt Grafting and Blending and Its Fatigue Resistance,TQ325.14
  8. Process Safety Research of Polypropylene Plant,TQ325.14
  9. Synthesis and Visible Light-Driven Photocatalytic Performances of Silver Halide/Conducting Polymer Nanocomposites,TB383.1
  10. Reaction Sintering Preparation of Titaniferous Compound Ceramic Composites by Two-step Method,TQ174.1
  11. Preparation and Investigation on the Properties of Three-Dimensional Braided Quartz Fiber Reinforced Composites,TB332
  12. Studies on Damping Modification of Fiber Reinforced Composites,TB332
  13. Studies on Genotoxicity of Two Novel Contraceptive Materials,R114
  14. Large composite structures falling weight impact test technique,TB302
  15. Wood composite viscoelastic constitutive heat and thermal forming simulation study,TB332
  16. Preparation of Fe3O4-MWCNTs Nanocomposites by Microwave Assisted Polyol Method and Their MRI Enhancement Properties,TB383.1
  17. Research of Preparation Technology of High Performance and Low Cost Aluminum Composite Materials,TB331
  18. Fabrication of Microscale Ordered-reinforced Composite and Its Mechanical Characterization,TB33
  19. Composite materials by mechanical shear load connector pin load distribution of,V229.7
  20. Marine research early age cracking of high performance concrete,TU528
  21. Polypropylene initial crystal structure of the pressure -induced flow-forming role in regulating,TQ325.14

CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Composite materials > Non-metallic composite materials
© 2012 www.DissertationTopic.Net  Mobile