Asymmetric metallocene catalysts [Elektronische Ressource] : design of ultrahigh molecular weight polypropylene plastomers / vorgelegt von Cecilia Cobzaru

Ccobzaru

Informations

• Publié par: universitat_ulm
• Publié le: 01 janvier 2006
• Nombre de lectures: 7
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

ASYMMETRIC METALLOCENE CATALYSTS
DESIGN OF ULTRAHIGH MOLECULAR WEIGHT
POLYPROPYLENE PLASTOMERS


Dissertation
zur Erlangung des Doktorgrades Dr. rer. nat.
der Fakultät für Naturwissenschaften
der Universität Ulm
vorgelegt von

CECILIA COBZARU

aus GHERAESTI / RUMÄNIEN
2006



















Amtierender Dekan: Prof. Dr. K.-D. Spindler
1. Gutachter: Prof. Dr. B. Rieger
2. Gutachter:
Tag der Promotion: Table of Contents

Chapter 1 Introduction
1.1 Benefits of plastics 1
1.2 Major markets of plastics and thermoplastics 3
1.3 Polypropylene products 5

Chapter 2 Tailor-made polyolefine materials via metallocene catalysts
2.1 Single site catalysts 11
2.2 Activators of the catalyst precursors 13
2.3 Stability of the active species 14
2.4 C - symmetric metallocenes. Strategies of catalyst development 15 1
2.5 Polypropylene microstructure and material properties 17
2.6 Content and significance of the study 18

Chapter 3 Synthesis of plastomeric polypropylenes
3.1 New ligands and complexes toward olefines
homo- and copolymers 20
3.2 Ligand and complex synthesis 25
3.2.1 General procedure 25
3.2.2 Synthesis of indene derivatives 26
3.2.3 Ligand synthesis 27
3.2.4 Synthesis of the bridged complexes 32
3.2.5 Synthesis of the unbridged complexes 33
3.2.6 Solid state structure 34
3.3 Experimental section
3.3.1 General Procedure 39
3.3.2 X-ray Crystallography 39
3.3.3 Preparation of the indenes 39
3.3.4 Preparation of 1-(9-Fluorenyl)-2-bromethane 43
3.3.5 Preparation of the bridged ligands 43
3.3.6 Preparation of the bridged complexes 45
3.3.7 Preparation of the unbridged complexes 46
iChapter 4 Propylene polymerization experiments
4.1 Polymerization mechanism 47
4.2 Activity and molecular weight 51
4.3 Polymerization studies with catalyst 12 52
4.4 Experimental section 53
4.4.1 Polymerization reactions in toluene solution 53
4.4.2 Polymerization reactions in liquid propylene 53
4.4.3 Polymer analysis 53

Chapter 5 Propylene/ethylene copolymerization reactions
5.1 Background and motivation 54
5.2 Copolymerization results 56
5.3 Experimental section 59
5.3.1 Copolymerization reactions under controlled conditions 59
5.3.2 Copolymer analysis 60

Chapter 6 Homopolypropylenes. Solid state properties
6.1 Solid state properties 61
6.1.1 Morphology of polypropylene 61
6.1.2 Crystalline structure 62
6.1.3 Crystalline modifications 64
6.2 Impact of the isotactic blocks length on material properties 66
6.2.1 Background and motivation 66
6.2.2 Isotactic block lengths from NMR 68
6.2.3 Isotactic block lengths from DSC 71
6.2.4 n and polymer crystalline structure 77 iso
6.2.5 n and viscoelastic properties 81 iso
6.3 Material properties. Stress-strain behaviour 84
6.4 n of low to high isotactic polymers prepared iso
by C and C catalysts 87 1 2
6.5 Experimental section 91
6.5.1 General procedure 91
ii
6.5.2 Molecular weights and molecular
weight distributions 91
6.5.3 Nuclear magnetic resonance spectra 91
6.5.4 Film preparation 91
6.5.5 Differential scanning calorimetry 91
6.5.6 Wide angle X-ray diffraction 92
6.5.7 Dynamic mechanical analysis 92

Chapter 7 Summary 93
Zusammenfassung 99

Literature 105

Acknowledgments 112

Curiculm Vitae 115
iiiAbbreviations and symbols



Å Angström
ABS Acrylonitrile butadiene styrene plastics
AlCl Aluminiumtrichloride 3
B(C F ) Triphenyl borane 6 5 3
BuLi n-Butyllithium
BOPP Biaxially oriented polypropylene
C Carbon
[C ] Ethylene concentration 2
[C]Propyleneconcentration 3
CaH Calcium hydride 2
CAO Computer-assisted optimization
CDCl Deuterated chlorophorm3
C D Cl Deuterated tetrachlorethane 2 2 4
CH Cl Dichlomethane 2 2
C Cyclopentadienyl p
∆ Chemical shift
dDoublet
DMA Dynamic Mechanical Analysis
DSC Differential Scanning Calorimetry
EA Elemental analysis
EtEthyl
EtODiethylether2
FDA Food and Drug Administration
Flu Fluorenyl
F Formula weight w
gGram
GC-MS Gas-chromatographic Mass Spectrometry
GPC Gel Permeation Chromatography
h hour
HHydrogen
HfCl Hafnium tetrachloride 4
ivHMS-PP High melt strength polypropylene
Ind Indenyl
KKelvin
K CO Potassium carbonate 2 3
kN Kilonewton
Strain λ
LiAlH Lithium aluminium hydride 4
LiCl Lithium chloride
mMultiplet
MMetal
MAC Methacrylic acid chloride
MAO Methyl aluminoxane
MeMethyl
MeOHMethanol
MPa MegaPascal
m/zMass/charge
M Molecular Weight w
NaBH Sodium borhydride 4
Na SO Sodium sulfate 2 4
NOESY Nuclear Overhauser Effect Spectroscopy
NMR Nuclear Magnetic Resonance
OEM Original equipment manufacturer
OPP Oriented polypropylene
pPressure
PAPolyamide
PBT Polybutylene terephtalate
PCPolycarbonate
PETPolyethyleneterephtalate
Ph Phenyl
PMMAPolymethylmethacrylate
POMPolyoxymethylene
PP Polypropylene
PPAPolyphosphoricacid
PPEPoly(p-phenyleneethynylene)
vppm Parts per million
PS Polystyrene
PTFEPolytetrafluoroethylene
p-Tos-OH Para-toluene sulfonic acid
PVC Polyvinylchloride
PURPolyurethane
r Reactivity ratio of propylene P
s Singlet
SiSilicium
tTriplet
T Glass transition temperature g
T Melting point m
THF Terahydrofurane
TIBATriisobutylaluminum
TPThermoplastic
TPE PP Thermoplastic elastic polypropylene
UHM Ultrahigh molecular weight w
WAXS Wide Angle X-ray Scattering
ZrCl Zirconium tetrachloride 4
ZN Ziegler Natta
viChapter 1 Introduction
1 INTRODUCTION
1.1 Benefits of plastics
In order to face today's very competitive environment, manufacturers put a lot of emphasis on
product differentiation while maintaining good margins and low cost. This differentiation is
done by design, visual appearance or by development of new functionalities requiring
miniaturized or more sophisticated systems. Part rationalization is another significant trend in
industries such as automotive, appliances, electronics and medical, as it increases end product
reliability and significantly decreases inventories. For these reasons the use of plastics to
replace metal and other traditional materials is continuously becoming a key strategy in many
markets all over the world.

Benefits of thermoplastics versus metals





This trend is expanding rapidly due to the multiple benefits provided by plastics compared to
metal. All of them lead to significant productivity improvements and/or product diffe-
rentiation.
1Chapter 1 Introduction
Compared to plastics, metals still have some advantages such as: higher strength and stiffness,
inherent thermal and electrical conductivity and inherent flame retardance.
There is enormous potential for metal replacement across all industries. Plastic applications
cover today 15% of their capability in metal replacement. The development of high
performance materials with tailor-made property profiles combined with the development of
advanced CAO (computer aided optimization) tools to optimize design and mold tools will
probably accelerate this trend.
For many years glass was extensively used, however, nowadays it is being replaced more and
more by transparent polymers providing much higher design flexibility, much easier
processability, better colorability/decoration and significant weight savings.

Benefits of Plastics versus Glass


The combination of transparency with other performances such as gas barrier, flame
retardancy, dimensional stability, and chemical resistance, raises the interest of many
manufacturers.

2