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Solubility of fluorinated polymers in supercritical carbon dioxide [Elektronische Ressource] / vorgelegt von Medhat Sherif Fahmy

145 pages
Solubility of Fluorinated Polymers in Supercritical Carbon Dioxide Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der Rheinisch-Westfälischen Technischen Hochschule Aachen vorgelegte Dissertation zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von M.Sc. Sherif Medhat Fahmy aus Kairo/Ägypten Berichter: Universitätsprofessor. Dr. Martin Möller Universitätsprofessor. Dr. Franz-Joseph Wortmann Tag der mündlichen Prüfung: 22.12.2005 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar Dedication This thesis is dedicated to the soul of my parents, Mr. Medhat Fahmy and Mrs. Olfat Rashad, for their loving supports throughout my whole life. They are always and forever be in my heart and my mind.
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Solubility of Fluorinated Polymers
in Supercritical Carbon Dioxide





Von der Fakultät für Mathematik, Informatik und Naturwissenschaften der
Rheinisch-Westfälischen Technischen Hochschule Aachen vorgelegte
Dissertation zur Erlangung des akademischen Grades eines Doktors der
Naturwissenschaften genehmigte Dissertation


vorgelegt

von


M.Sc.
Sherif Medhat Fahmy


aus Kairo/Ägypten



Berichter: Universitätsprofessor. Dr. Martin Möller
Universitätsprofessor. Dr. Franz-Joseph Wortmann




Tag der mündlichen Prüfung: 22.12.2005

Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar

Dedication

This thesis is dedicated to the soul of my parents, Mr. Medhat Fahmy and Mrs. Olfat
Rashad, for their loving supports throughout my whole life. They are always and
forever be in my heart and my mind.




Sherif Fahmy



















































“There is no limit in doing chemistry in carbon dioxide,
just because it’s neat and green candidate, and green is
the color of money”



S.K. Ritter in C&EN July 16, 2001

The work presented in this dissertation has been done partially in the time from 01.08.2001 to
31.08.2002 at the Department of Macromolecular Chemistry III/ Materials, University of Ulm,
and in the time from 01.09.2002 to 30.11.2004 at the Chair for Textile Chemistry and
Macromolecular Chemistry, Institute for Technical Chemistry and Macromolecular chemistry,
Aachen University of Technology under supervision of Prof. Dr. rer. nat. Martin Möller.
Content


List of Abbreviation…………………………………………………………………………....i

Chapter 1 :Introduction…………………………………………………………………….....1

1.1 Supercritical fluid technology as a tool for environmental problem solving……....1
1.2 Content of the thesis………………………………………………………………..3
1.3 References.................................................................................................................5

Chapter 2 : Carbon dioxide-polymer interactions; literature overview…………................6
2.1 Fundamentals of supercritical fluids……………………………………………….6
2.2 Thermodynamics of polymer-supercritical fluid systems.......................................10
2.3 Phase diagram of polymer-CO mixtures………………………………………....12 2
2.3.1 Types of binary phase diagrams..........................................................................12
2.3.1.1 Effect of physical properties of the polymer……………………………..….12
2.3.1.2 Effect of polymer concentration…………………………………………......17
2.3.1.3 Effect of the polymers molecular weight.........................................................17
2.3.1.4 ymer solidification……………………………………………...18
2.4 Solubility of (co) polymer in supercritical solvents………………………….…...20
2.5 Fluoropolymers-carbon dioxide interaction behavior………………………….....24
2.6 Effect of co-solvents on the cloud point of polymers in CO ………………….....26 2
2.7 Crystallization techniques from scCO ……………………………………….…..28 2
2.8 References………………………………………………………………….…......31

Chapter 3 : Precipitation/crystallization behaviour of polyvinylidene fluoride
(PVDF) in scCO …………………………………………………………....……35 2

3.1 Introduction……………………………………………………………...…….......35
3.2 Experimental section…………………………………………………………........38
3.3 High pressure experimental setup……………………………………………........39
3.4 Precipitation/crystallization of PVDF in scCO ……………………………….......46 2
3.5 Conclusion……………………………………………………………………........66
3.6 References…………………………………………………………………….........67

Chapter 4 : Phase behavior of novel molecularly designed macromolecular stabilizers
in scCO .……………………………………………………………………….......68 2

4.1 Introduction……………………………………………………………...………....69
4.2 Experimental section……………………………………………………………….70
4.3 Impact of molecular architecture on the solubility in scCO ……………………....74 2
4.4 Solubilization of commercial macromolecular stabilizers …………………….......78
4.5 Conclusion………………………………………………………………………….81
4.6 References………………………………………………………………………….82
4.7 Appendix: on the solubility of novel molecularly designed block and
statistical copolymer in scCO ……………………………………….....84 2

Chapter 5 : Impact of low and high molecular weight additives on the cloud point for
PVDF in cCO …………………………………………………………………....90 2

5.1 Introduction……………………………………………………………...……........ ..90
5.2 Experimental section…………………………………………………………….. .....92
5.3 Impact of some low molecular weight compounds ………………………...…... ......96
5.4 Effect of hexafluoropropene (HFP)…………………………………………….. .....102
5.5 Impact of high molecular weight macromolecules…………….……….…...............105
5.6 Conclusion…………………………………………………………………….... .....108
5.7 References………………..………………………………………………….. ..........109

Chapter 6 : Effect of molecular weight of crystallized PVDF from scCO …………….......111 2

6.1 Introduction……...…………………………….………………………...……. ……111
6.2 Experimental section…………………………..………………………………. .......112
6.3 Effect of the molecular weight on crystallization …….………………………. .......114
5.4 Conclusion………………………………………………………………………. ....120
5.5 References………………………………………………………………….... …......121


Summary ..……………………………………………………………………………………...123

Zussammenfassung………………………………………………………………………….....127

Acknowledgement

Lebenslauf








List of Abbreviations

Chemicals
CO Carbon dioxide 2
PERC Perchloroethylene
PVDF Polyvinylidene fluoride
HFP Hexafluoropropene
PEA Polyethylacrylate
PBA Polybutylacrylate
PEHA Polyethylhexylacrylate
PVAc Polyvinyl acetate
PODA Polyoctadecylacrylate
PMA Polymethylacrylate
EMA Ethylmethacrylate
PEO Polyethylene oxide
PS Polystyrene
PTFE (Teflon) Polytetrafluoroethylene
Tefoln-AF DuPont’s Teflon commercial product 160
PVF Polyvinyl fluoride
F8H2A 1H, 1H, 2H, 2H Perfluorodecylacrylate
DME Dimethyl ether
PMMA Polymethymethacrylate
PLLA Poly(L-Lactide)
sPS Syndiotactic polystyrene
PET Polyethylene terephthalate
DMF N,N- Dimethylformamide
DMAc N, N- Dimethylacetamide
THF Tetrahydrofuran
PFOA 1,1- Dihydrochlorofluorooctylacrylate
Freaon-113 1,2-Trichloro-1,2,2-trifluoroethene
HFX Hexafluoro-m-xylene
PDMS Polydimethylsiloxane
Kynar 741 Polyvinylidene fluoride M =323 kg/mol (Elf Atochem) w
i Abbreviations
Solef1010 Polyvinylidene fluoride M =226 kg/mol (Solvay) w
DMSO Dimethyl sulfoxide
NMP N- methylpyrroldidone
Krytox Perfluoropolyether (DuPont’s Product)

Units & Sympole

PVT Pressure/temperature/volume correlation diagram
T Critical Temperature c
P Critical Pressure c
α()T Temperature viral coefficient
s Second
∆Η Change in Enthalpy on mixing mix
∆S Change in Entropy on mixing mix
∆U Change in internal energy on mixing mix
χ Mole fraction i i
χ Mole fraction j j
Γ (r,T ) Intermolecular pair potential energy ij
g(r, ρ,T ) Radial distribution function
ρ(P,T ) Solution density
ρ(r) Average density
ω Interchange energy
Ζ Coordination number
α Polarizability
D Dipole moment
Q Quadruple moment
L+L (L+L) Liquid/Liquid demixing line
L+S (L+S) Liquid/Solid demi
LLV Liquid/Liquid/Vapour transition line
UCST Upper critical solution temperature
LCST Lower critical solution temperature
LV Liquid/Vapour transition line
P-x Pressure-composition correlation diagram
P-T Pressure-Temperature correlation diagram
iiAbbreviations

T Crystallization Temperature c
M Weight average molecular weight w
M Number average mot n
T Glass transition temperature g
T Melting temperature m
wt% weight percentage
ppm Part per million
δ Chemical shift
dP /dT Change pressure per time (depressurization time)
LCEP Low critical end point
UCEP High critical end point
∆Η Change in Enthalpy on melting m
µm Micrometer
*C Temperature dependent fraction VDF
blockf MMA weight fraction in block copolymer MMA
randomf MMA weight fraction in statistical copolymer MMA
Å Angstrom
*P Intersection pressure
*T Intersection temperature
UCEP Upper critical end point
LCEP Lower critical end point

General

sc Supercritical
VOC Volatile Organic Compound
PRE Peng Robinson equation of state
DSC Differential Scanning Calorimetry
SEC Size Exclusion Chromatography
13 13C C Nuclear Magnetic Resonance
NIST National Institute of Standards
UV/vis Ultraviolet-visible light source
SEM Scanning Electron micrograph
iii Abbreviations
SAFT Statistical Associating Fluid Theory
EU European Union
LPREI/CPREI Laboratory of polymer reaction engineering
AUT Chemical Process Engineering Institute, Aristotle University
of Technology, Hellas
ATRP Atom Transfer Radical Polymerization
GUC German University in Cairo

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