Date post: | 12-Jun-2015 |
Category: |
Technology |
Upload: | malcolmmackley |
View: | 674 times |
Download: | 0 times |
1
Some brilliant Polymer Scientist and brilliant Polymer Science.
ByProfessor Malcolm Mackley
Department of Chemical Engineering and Biotechnology
University of Cambridge UK
Nantes September 2011
2
3
Brilliant Polymer Scientist, 1
1940s
W and H Kuhn
Swiss Physical Chemists
4
1940s, Werner and Hans Kuhn
Werner Kuhn Hans Kuhn1900 1950 2000 2010
WK HK
5
d)rb(b
d)z,y,x(P 222/3
3
R0
a
n links
Root mean square end to end distance
1/20
1/22 n a Rr
1934 Kuhn Random Coil
d))z,y,x(Pln(kS
22rkbcS
22
na2
3b
Probability distribution
Entropy
6
Rubber Elasticity Kuhn and Treloar 1950s
1
2
3
N crosslinks /unit volume
)3(NkT2
1W 2
322
21
)3(Nk2
1S 2
322
21
STw
1dw 1321
)1
(NkT21
1
Entropy change
Energy change entropic
Incompressible Mechanical work
Constitutive equation
Molecular - Macro
7
Brilliant Polymer Scientist, 2
1950- 70s
Andrew Keller
Hungarian Physical Chemist
8
Andrew Keller
1900 1950 2000 2010AK
9
Andrew Keller
• Polymer crystallisation
10
Polyethylene single crystals
11
1955-1990s Polyethylene solution crystallisation
12
1980 Polyethylene nano and microstructure
13
Low density polyethylene AFM
14
Brilliant Polymer Scientist, 3
1970- 2000s
Pierre de Gennes
French Physicist
15
Pierre de Gennes
1900 1950 2000 2010PdG
16
Pierre de Gennes
• Superconductivity
• Liquid crystals
• Polymers
• Soft Matter
17Graphic courtesy of Alexi Likhtman, University of Reading
18
Polymer Reptation
3n 0
19
Linear viscoelasticty of polymer melt
10
100
1000
10000
100000
0.1 1 10 100 1000frequency (rad/s)
G' (
Pa
), G
'' (P
a),
*
(Pa
.s)
G'G''eta*
1
10
100
1000
10000
100000
0.001 0.01 0.1 1 10 i (s)g
i (P
a)
20
Multimode Pom-Pom model
Viscoelastic stress:
Backbone orientation:
Stretch:
Time scales:
1988 McLeish and Larson
McLeish, TCB Larson, RC J. Rheol. 42, 1 81-110 (1998)
21
22dP = 3.96 bardP = 3.76 bar
Vp = 0.44 mms-1
3D simulation Experiment
3D EUsolve
Polystyrene (PS2)
10mm depth
LHS Pom Pom
RHS Experiment
23
Brilliant Polymer Scientist, 4
1950- 1980s
Sir Charles Frank
English Physicist
1900 1950 2000 2010FCF
24
Sir Charles Frank
25
Sir Charles Frank
• Dislocations; Frank-Read source
• Liquid crystals; Frank elasticity
• “Meson catalysed Cold fusion”
• Polymer crystallisation
• High modulus polyethylene
26
Polyethylene
Diamond
ExpectE=285 GPaNot usualE=1 GPa
Frank 1970
Bunn 1934
27
The stretching of Polymer; Chains Peterlin and Ziabicki 1960s
PolymerChain extension
chainpolymer of time relaxation chain τrate, strain γ γ β
number criteria for polymer chain extension 1
Kinetic Theory of Kuhn and Kuhn 1940s
Kuhn and Kuhn 1940s
28
Chain extension with opposed jets
B number criteria for chain extension 1
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)
30
x0 ,y0
x1 , y1
31
1
0 t
B number criteria for chain extension
Strain criteria for chain extension
32
Shish KebabCore;Extended chain
Shish Kebab Polyethylene fibrous crystalsSolution processing.
Mackley 1970
33
Brilliant Polymer Scientists, 5
1980s
Piet Lemstra and Paul Smith
Dutch Polymer Scientists
34
Paul Smith.Now ETH
Piet LemstraNow TU Eindhoven
Smith and Lemstra 1980
1900 1950 2000 2010
35P. Smith, and P.J.Lemstra, J. Material. Sci. 1980, 15, 505
1. Low entanglement UHMWPE polymer gel
2. Unoriented Gel fibre
Quench bath
3. Unoriented Low entanglement semi crystalline fibre
4. Hot draw
5. Oriented High Modulus Polyethylene
Solvent recovery
Piston
Low entanglement,Gel Drawing
36
Continuous processing of UHMWPE Dyneema
Screw extruder
UHMWPE Polymer powder SolventLow entanglement polymer gel
Spinneret
Gel fibres
Quench bath
Low entanglement semi crystalline fibre
Hot draw
Solvent recovery
High Modulus Polyethylene
Smith and Lemstra J Mat Sci 1980
37
2000Whitstable UK
Mackley 2000
DyneemaHigh moduluspolyethyleneropes
38
Common Factors
• Intelligence
• Genuine interest, motivation
• Physical and Scientific insight
• Appreciation of both experimental and theoretical aspects
• Something special