Table Of ContentComplex Macromolecular Architectures by Living Cationic
Polymerization
Thesis by
Reem D. Alghamdi
In Partial Fulfillment of the Requirements
For the Degree of
Master of Science
King Abdullah University of Science and Technology,
Thuwal, Kingdom of Saudi Arabia
© May 2015
Reem D. Alghamdi
All Rights Reserved
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EXAMINATION COMMITTEE APPROVAL FORM
The thesis of Reem D. Alghamdi is approved by the examination committee.
Committee Chairperson: Professor Nikos Hadjichristidis
Committee Member: Professor Suzana Nunes
Committee Member: Professor Luigi Cavallo
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ABSTRACT
Complex Macromolecular Architectures by Living Cationic Polymerization
Reem D. Alghamdi
Poly (vinyl ether)-based graft polymers have been synthesized by the combination
of living cationic polymerization of vinyl ethers with other living or controlled/
living polymerization techniques (anionic and ATRP). The process involves the
synthesis of well-defined homopolymers (PnBVE) and co/terpolymers [PnBVE-b-
PCEVE-b-PSiDEGVE (ABC type) and PSiDEGVE-b-PnBVE-b-PSiDEGVE (CAC type)] by
sequential living cationic polymerization of n-butyl vinyl ether (nBVE), 2-
chloroethyl vinyl ether (CEVE) and tert-butyldimethylsilyl ethylene glycol vinyl
ether (SiDEGVE), using mono-functional {[n-butoxyethyl acetate (nBEA)], [1-(2-
chloroethoxy) ethyl acetate (CEEA)], [1-(2-(2-(t-butyldimethylsilyloxy)ethoxy)
ethoxy) ethyl acetate (SiDEGEA)]} or di-functional [1,4-cyclohexanedimethanol
di(1-ethyl acetate) (cHMDEA), (VEMOA)] initiators. The living cationic
0
polymerizations of those monomers were conducted in hexane at -20 C using
[1]
Et3Al2Cl3 (catalyst) in the presence of 1 M AcOEt base. The PCEVE segments of the
synthesized block terpolymers were then used to react with living macroanions (PS-
DPE-Li; poly styrene diphenyl ethylene lithium) to afford graft polymers. The
+ -
quantitative desilylation of PSiDEGVE segments by n-Bu4N F in THF at 0 °C led to
graft co- and terpolymers in which the polyalcohol is the outer block. These co-
/terpolymers were subsequently subjected to “grafting-from” reactions by atom
transfer radical polymerization (ATRP) of styrene to afford more complex
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macromolecular architectures. The base assisted living cationic polymerization of
vinyl ethers were also used to synthesize well-defined α-hydroxyl polyvinylether
(PnBVE-OH). The resulting polymers were then modified into an ATRP macro-
initiator for the synthesis of well-defined block copolymers (PnBVE-b-PS).
Bifunctional PnBVE with terminal malonate groups was also synthesized and used
as a precursor for more complex architectures such as H-shaped block copolymer by
“grafting-from” or “grafting-onto” methodologies, which yielding in well-defined
PVEs segments with control Mn(GPC) = [VE]/[initiator] and narrow MWDs.
Scheme A. Complex macromolecular architectures by combination of living cationic polymerization with other
polymerization techniques.
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ACKNOWLEDGMENTS
With deepest gratitude to “Allah” my lord who awards me the soul of inspiration and
patience to continue working till now, and whom gives His promise to exalt those
who work hard and pursue the path of science,
As his prophet (peace be upon him) said: "the priority of the learned man over the
pious worshipper is such like the full moon comparing to the rest of stars (mean in
brightness), and the learners are the successor of the Prophets”. [At-Tirmidhi, Hadith Hassan]
After that, I would like to thank King Abdullah University of Science and Technology
(KAUST) which gave me the opportunity to meet many capable and eligible persons
and for a huge financial support.
No words will describe my warm gratefulness for all advices and guidance that I
received from my advisor Professor Nikos Hadjichristidis, whom I am not capable to
repay for his kindness, all continuous supporting and insightful comments, as well
as for introducing me to the beautiful field of Polymer Chemistry.
My acknowledgment also goes to the committee members, Professor Suzana Nunes
and Luigi Cavallo, for their criticisms and sharing their precious time in order to
direct this research to the privilege path.
All efforts, help and significant explanations which I learned from Dr.Hassen
Bouchekif during my research is greatly appreciated I can’t thank him enough.
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Also, I would like to thank University of Al-Baha who gives me a chance to complete
my graduate study,
Last but not the least,
I am grateful totally to my lovely husband for supporting me spiritually, for his
patience and endurance my bad mood and dereliction during research period, as
well as my family for enlightening me the first glance of academic life and for their
ceaseless prayer for me,
and I would like to extend my thank to reach all who helped me and my closest lab
mate Reem Alshumrani for the motivational discussions and for all the wakefulness
nights we were working together before deadlines,
Thanks for all whom will read this thesis in order to learn.
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TABLE OF CONTENTS
Page
EXAMINATION COMMITTEE APPROVAL FORM …………………………………………… 2
ABSTRACT ……………………………..…………………………………………………………………… 3
ACKNOWLEDGMENTS ………………………………………………………………………………… 5
CHAPTER 1 INTRODUCTION …………………………………………..…………………………. 13
1.1 Background of the study………………………………………………………………………… 13
1.2 Living cationic polymerization and base assisted living cationic
polymerization…………………………………………………………………………………………… 15
1.2.1 History of living cationic polymerization …………………………..………….. 15
1.2.2 Base assisted living cationic polymerization …………………………………. 17
1.3 Macromolecular engineering by living cationic polymerization of VE
monomers…………………………………………………………………………………………………... 18
1.4 Other controlled/living and living polymerization techniques ………………… 21
1.4.1 Atom transfer radical polymerization (ATRP) ……………………………….. 21
1.4.2 Cationic Ring-Opening polymerization (ROP) ………………………………... 23
1.4.3 Anionic polymerization ………….………...……………………………..................... 24
1.5 Objectives of the work .…..……………………………………………………………………… 25
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1.6 Study questions ...……………….………………………………………………………………….. 26
1.7 Research limitations …………..…………………………………………………………………. 26
CHAPTER 2 EXPERIMENTAL …………………………………………………………………….. 27
2.1 Materials ………………………………………………………………………………………………. 27
2.2 Initiators ………………………………………………………………………………………………. 28
2.2.1 Synthesis of the nBVE-acetic acid adduct (nBEA) …………………………… 28
2.2.2 Synthesis of the SiDEGVE-acetic acid adduct (SiDEGEA) ………………… 29
2.2.3 Synthesis of the CEVE-acetic acid adduct (CEEA) …………………............... 30
2.2.4 Synthesis of the VOEM-acetic acid adduct (VEMOA) ……………………….. 30
2.2.5 Synthesis of cHDMEA ……………………………………………………………………. 33
2.3 Monomers ………………………………….………………………………………………………….. 33
2.3.1 Synthesis of 2-(tert-butyldimethylsilyloxy) diethylene glycol vinyl ether
(SiDEGVE) …………………………………………………………………………………………… 34
2.3.2 Synthesis of (2-(Vinyloxy) ethyl) malonate (VOEM) ….…………………… 35
2.4 General procedures for the homopolymerization of vinyl ethers using mono and
difunctional initiators (nBEA, CEEA, SiDEGEA and VEMOA) ………………………….. 38
2.4.1 Homopolymerization of nBVE using the nBEA initiator ………………….. 39
2.4.2 Homopolymerization of nBVE using CEEA initiator ………………………... 41
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2.4.3 Homopolymerization of nBVE using SiDEGEA initiator (monofunctional
chain-end, a precursor for ROP and ATRP) …………………………………………….. 44
2.4.4 Homopolymerization of nBVE using VEMOA initiator (difunctional chain-
end, a precursor for miktoarms stars) …………………………………………………… 46
2.4.5 Homopolymerization of nBVE using nBEA initiator (chain-end
functionalization, a precursor for miktoarm polymers) ………………………….. 48
2.5 General procedures for the synthesis of block co- and ter-polymers by sequential
monomers addition using the Schlenk technique at −20 °C in n-Hex ………………. 50
2.5.1 Synthesis of PnBVE100-b-P(nBVE80-co-VOEM20)100 in n-Hex at −20 °C .… 52
2.5.2 Synthesis of P(nBVE0.8-co-VOEM0.2)50-b-PnBVE100-b-P(nBVE0.8-co-
VOEM0.2)50 ……………………………………………………………………………………………...... 54
2.5.3 Synthesis of PnBVE200-b-PCEVE216-b-PSiDEGVE192 in n-Hex at −20 °C … 55
2.5.4 Synthesis of PSiEGVE100-b-PnBVE550-b-PSiEGVE100 in n-Hex at −20 °C … 55
2.6 Synthesis of graft triblock quarterpolymer [PnBVE200-b-(P(CEVE0.2-co-(CEVE-g-
PS13)0.8)216-b-PSiDEGVE192] by combination of living cationic polymerization and
living anionic polymerization ……………………………………………………………………… 56
2.6.1 Anionic polymerization of styrene (grafting segments) …………..……… 56
2.6.2 Solvent preparation for “grafting-onto” reaction …………………………… 57
2.6.3 Combination of living cationic polymerization with living anionic
polymerization …………………………………………………………………………………….. 58
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2.7 General procedure for the synthesis of block copolymers and graft terpolymers
by combination of cationic polymerization and ATRP ………….………………………… 59
2.7.1 Blank tests of styrene via ATRP ……………………………………………………… 61
2.7.1.1 Blank tests of styrene via ATRP in bulk ………………………………. 61
2.7.1.2 Blank tests of styrene via ATRP in Toluene ………………............... 62
2.7.2 Synthesis of PnBVEx-b-PSx by combination of cationic polymerization of
end-functionalized homopolymer (SiO-PnBVE) with ATRP of styrene ……… 64
2.7.2.1 Desilylation of the end-functional chain (-OSi) ……………………. 64
2.7.2.2 Synthesis of PnBVE-based ATRP macroinitiator (functionalization
of the end-group) ……………….................................................................................. 66
2.7.2.3 Synthesis of PnBVE50-b-PS200, PnBVE100-b-PS200 by combination of
cationic polymerizetion with ATRP ……………………………………………….. 69
2.7.3 Synthesis of ((PDEGVE1-x-g-PSx)100-b-PnBVE550-b-(PDEGVE1-x-g-PSx)100)
by combination of cationic polymerization of (PSiDEGVE100-b-PnBVE550-b-
PSiDEGVE)100 and ATRP ……………………………………………………..…………………… 71
2.7.3.1 Desilylation of PSiDEGVE blocks …………………………………..……… 71
2.7.3.2 Synthesis of PDEGVE-based ATRP multi-macroinitiator ……….. 73
2.7.3.3 Synthesis of ((PDEGVE1-x-g-PSx)100-b-PnBVE550-b-(PDEGVE1-x-g-
PSx)100) by combination of cationic polymerization and ATRP ............... 74
