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Brilliant Polymer Scientist-Nantes-2011

This presentation was given at Ecole Centale Nantes in 2011 and describes a number of brilliant polymer scientists who have influenced my own work.

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Brilliant Polymer Scientist-Nantes-2011

  1. 1. Nantes September 2011Some brilliant Polymer Scientist and brilliant Polymer Science. By Professor Malcolm Mackley Department of Chemical Engineering and Biotechnology University of Cambridge UK 1
  2. 2. 2
  3. 3. Brilliant Polymer Scientist, 1 1940s W and H Kuhn Swiss Physical Chemists 3
  4. 4. 1940s, Werner and Hans Kuhn Werner Kuhn Hans Kuhn1900 1950 2000 2010 WK HK 4
  5. 5. 1934 Kuhn Random Coil R0 n links 2 3 b = 2na 2 a b3Probability distribution P ( x , y, z ) dτ = ( − b 2 r 2 ) dτ π3 / 2 2 1/2Root mean square r = R 0 = a n1/2end to end distance Entropy S = k ln(P( x , y, z))dτ S = c − kb 2 r 2 5
  6. 6. Rubber Elasticity Kuhn and Treloar 1950s λ2 λ1 λ3 N crosslinks /unit volume 1Entropy change ∆S = − Nk (λ2 + λ2 + λ2 − 3) 1 2 3 2 1Energy change entropic ∆w = −T∆S ∆W = NkT(λ2 + λ2 + λ2 − 3) 1 2 3 2Incompressible λ1λ 2 λ 3 = 1 Mechanical work ∆w = σdλ1 1Constitutive equation σ = NkT(λ1 − ) λ2 1 Molecular - Macro 6
  7. 7. Brilliant Polymer Scientist, 2 1950- 70s Andrew KellerHungarian Physical Chemist 7
  8. 8. Andrew Keller1900 1950 2000 2010 AK 8
  9. 9. Andrew Keller• Polymer crystallisation 9
  10. 10. Polyethylene single crystals 10
  11. 11. 1955-1990s Polyethylene solution crystallisation 11
  12. 12. 1980 Polyethylene nano and microstructure 12
  13. 13. Low density polyethylene AFM 13
  14. 14. Brilliant Polymer Scientist, 3 1970- 2000s Pierre de Gennes French Physicist 14
  15. 15. Pierre de Gennes1900 1950 2000 2010 PdG 15
  16. 16. Pierre de Gennes• Superconductivity• Liquid crystals• Polymers• Soft Matter 16
  17. 17. Graphic courtesy of Alexi Likhtman, University of Reading 17
  18. 18. Polymer Reptation 3 τ =τ0 n 18
  19. 19. Linear viscoelasticty of polymer melt 100000 100000G (Pa), G (Pa), * (Pa.s) 10000 10000 1000 1000 100 gi (Pa) 100 G 10 G eta* 10 1 0.1 1 10 100 1000 frequency (rad/s) 0.001 0.01 λ i (s) 0.1 1 10 19
  20. 20. 1988 McLeish and Larson Multimode Pom-Pom modelViscoelastic stress:Backbone orientation:Stretch:Time scales: McLeish, TCB Larson, RC J. Rheol. 42, 1 81-110 (1998) 20
  21. 21. 21
  22. 22. Vp = 0.44 mms-13D EUsolvePolystyrene (PS2)10mm depthLHS Pom PomRHS Experiment 3D simulation Experiment dP = 3.76 bar 22dP = 3.96 bar
  23. 23. Brilliant Polymer Scientist, 4 1950- 1980s Sir Charles Frank English Physicist1900 1950 2000 2010 FCF 23
  24. 24. Sir Charles Frank 24
  25. 25. Sir Charles Frank• Dislocations; Frank-Read source• Liquid crystals; Frank elasticity• “Meson catalysed Cold fusion”• Polymer crystallisation• High modulus polyethylene 25
  26. 26. Frank 1970 PolyethyleneBunn 1934 Diamond Expect E=285 GPa Not usual E=1 GPa 26
  27. 27. Kuhn and Kuhn 1940s The stretching of Polymer; Chains Peterlin and Ziabicki 1960s Kinetic TheoryPolymer ofChain extension Kuhn and Kuhn 1940s β = γτ  γ = strain rate, τ = chain relaxation time of polymer chain  Β number criteria for polymer chain extension β = γ τ ≥ 1 27
  28. 28. Chain extension with opposed jetsB number criteria for chain extension β = γ τ ≥ 1 28
  29. 29. Localized Flow Birefringence of Polyethylene Oxide Solutions in a Four Roll Mill 1974 Crowley et al. Journal of Polymer Science: Vol 14 1111-1119 (1976) 29
  30. 30. x0 ,y0 x1 , y1 30
  31. 31. B number criteria for chain extension β = γ τ ≥ 1 Strain criteria for chain extension γ t ≥ γ 0 31
  32. 32. Mackley 1970 Shish Kebab Polyethylene fibrous crystals Solution processing.Shish KebabCore;Extended chain 32
  33. 33. Brilliant Polymer Scientists, 5 1980sPiet Lemstra and Paul Smith Dutch Polymer Scientists 33
  34. 34. Smith and Lemstra 1980 Paul Smith. Piet Lemstra Now ETH Now TU Eindhoven 1900 1950 2000 2010 34
  35. 35. Low entanglement,Gel Drawing Piston 1. Low entanglement UHMWPE polymer gel Solvent recovery2. Unoriented Gel fibre 4. Hot draw Quench bath 5. Oriented High Modulus Polyethylene 3. Unoriented Low entanglement semi crystalline fibreP. Smith, and P.J.Lemstra, J. Material. Sci. 1980, 15, 505 35
  36. 36. Continuous processing of UHMWPE Dyneema UHMWPE Polymer powder Solvent Low entanglement polymer gel Screw extruderSpinneret Solvent recovery Gel fibres Hot draw Quench bath High Modulus Polyethylene Low entanglement semi crystalline fibre Smith and Lemstra J Mat Sci 1980 36
  37. 37. Mackley 2000 Dyneema 2000 High modulus Whitstable polyethylene UK ropes 37
  38. 38. Common Factors• Intelligence• Genuine interest, motivation• Physical and Scientific insight• Appreciation of both experimental and theoretical aspects• Something special 38

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