5-substituted triazolinyls as novel counter radicals in controlled radical polymerization [Elektronische Ressource] / by Maxim Peretolchin

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Informations

• Publié par: johannes_gutenberg-universitat_mainz
• Publié le: 01 janvier 2005
• Nombre de lectures: 10
• Langue: English
• Poids de l'ouvrage: 4 Mo

Extrait

5-Substituted Triazolinyls as Novel
Counter Radicals in Controlled
Radical Polymerization

Thesis for completion of the degree
“Doktor der Naturwissenschaften”
in the Department of Chemistry and
Pharmaceutics of Johannes Gutenberg
University, Mainz







by
Maxim Peretolchin















Mainz 2004 The work completed between October 1999 and November 2002 at the Max-
Planck-Institute for Polymer Research, Mainz, Germany under the supervision
of
Prof. Dr. K. Müllen.





































4
Content

9 1 State of the art
1.1 Polymer Chemistry 9
1.1.1 Introduction 9
1.1.2 Characterization of polymers 11
1.2 Coordination polymerization 12
1.3 Ionic polymerization 12
1.4 Free radical polymerization 15
1.4.1 Principles of radical polymerization 15
1.4.2 Kinetics of free radical polymerization 19
1.4.3 Comparison of free radical and ionic (living) polymerization 21
1.5 Controlled (living) radical polymerization 23
1.5.1 Overview 23
1.5.2 Atom transfer radical polymerization (ATRP) 24
1.5.3 Reversible addition fragmentation chain transfer (RAFT) 26
1.6 Stable free radical polymerization (SFRP) 27
1.6.1 Nitroxide mediated radical polymerization (NMRP) 28
1.6.2 Controlled radical polymerization mediated by stable radicals other than
32
nitroxides
1.6.3 Carbon-centered radicals 33
1.6.4 Nitrogen-centered radicals 34
1.7 Triazolinyl radicals 34
1.7.1 Syntheses and properties 34
1.7.2 Triazolinyl mediated controlled radical polymerization 38
1.8 Comparison of ATRP, SFRP, and RAFT 39
1.9 Kinetics of SFRP 39
1.9.1 Self-regulation concept 43
1.10 Materials, academic, and industrial prospects 45
47 2 Goals of the current work
3 Results & discussion 51
3.1 Planning of syntheses of new triazolinyl derivatives 51
3.2 Development of synthetic route to benzhydrylamine derivatives 54
3.2.1 Previously used methods 54
5
3.2.2 Synthetic route via oximes 55
3.3 Syntheses of benzhydrylamine derivatives 56
3.3.1 Synthesis of 4,4`-(perfluoro-n-hexyl)benzophenone (73) and 4,4´-{2-[2-
56
(2-methoxy-ethoxy)-ethoxy]-ethoxy}benzophenone (70)
3.3.2 Syntheses of benzophenone oxime derivatives 57
3.3.3 Syntheses of benzhydrylamine derivatives from oximes 59
3.3.4 Sydrylamine derivatives functinalized by groups
61
sensitive to reduction
3.3.5 Syntheses of triazolins (cyclization step) 62
3.3.6 Syntheses of triazolinyls (oxidation step) 64
3.4 Properties of the synthesized triazolinyl radicals 66
3.4.1 Optical spectroscopy 66
3.4.2 ESR & stability 68
3.4.3 Other properties 86
3.5 Polymerization experiments in the presence of triazolinyl radicals 86
3.5.1 Polymerizations of styrene in the presence of triazolinyl radicals 87
3.5.2 Discussion of the styrene polymerization experiments 104
3.5.3 Polymerizations of methylmethacrylate (MMA) in the presence of
109
triazolinyl radicals
3.5.4 Discussion of MMA polymerization experiments 121
3.6 Polymerization of other monomers (non styrene and MMA) in the presence
126
of triazolinyl radicals
3.6.1 Polymerization of ethylmethacrylate (EMA) in the presence of 1,3–
126
3diphenyl-5,5-di(4-chlorophenyl)-∆ -1,2,4-triazolin-2-yl (77)
3.6.2 Polymerizations of 2,2,2-trifluoroethylmethacrylate (FEMA) in the
128
presence of triazolinyl radicals 77 and 86
3.6.3 Polymerization of n-butylmethacrylate (n-BMA) in the presence of 1,3–
132
3diphenyl-5,5-di(4-chlorophenyl)-∆ -1,2,4-triazolin-2-yl (77)
3.6.4 Polymerization of 4-vinylpyridine (4-VP) in the presence of 1,3-
135
3diphenyl-5,5-bis-4-dimethylaminophenyl-∆ -1,2,4-triazolin-2-yl (82)
3.6.5 Summary of the application of the triazolinyl radicals 77 and 82 for the
137
controlled radical polymerization of the methacrylates and 4-VP
6

3.7 Syntheses of block copolymers 138
3.7.1 Synthesis of block copolymers starting from polystyrene (PS)
140
macroinitiator
3.7.2 Symers initiated from polymethylmethacrylate
145
(PMMA) macroinitiator
4 Conclusions and outlook 154
5 Experimental part: syntheses 161
5.1 Synthesis of N-phenylbenzenecarbohydrazonoyl chloride 161
35.2 164 Synthesis of 1,3,5,5-tetraphenyl-∆ -1,2,4-triazolin-2-yl
35.3 167 Synthesis of 1,3–diphenyl-5,5-di(4-methoxyphenyl)-∆ -1,2,4-triazolin-2-yl
35.4 172 Synthesis of 1,3–diphenyl-5,5-di(4-chlorophenyl)-∆
35.5 Synthesis of 1,3-diphenyl-5,5-bis(4-dimethylaminophenyl)-∆ -1,2,4-
177
triazolin-2-yl
35.6 182 Synthesis of 1,3-diphenyl-5,5-di(4-biphenyl)-∆ -1,2,4-triazolin-2-yl
35.7 186 Synthesis of 1,3–diphenyl-5,5-di(4-fluorophenyl)-∆
35.8 Syntheses of 1,3–diphenyl-5,5-di(4-bromophenyl)-∆ -1,2,4-triazolin-2-yl
191
3and 1,3,5–triphenyl-5-(4-bromophenyl)-∆ -1,2,4-triazolin-2-yl
35.9 Synthesis of 1,3-diphenyl-5,5-di(nitrophenyl)-∆
197
(mixture of isomers)
25.10 Synthesis of 1,3-diphenyl-5,5-di(3-trifluoromethylphenyl)-∆ -1,2,4-
202
triazolin-2-yl
35.11 Synthesis of 1,3-diphenyl-5,5-di(4-(perfluoro-n-hexyl)phenyl)-∆ -1,2,4-
207
triazolin-2-yl
35.12 Synthesis of 1,3-diphenyl-5,5-di(2-thiophenyl)-∆ -1,2,4-triazolin-2-yl 214
25.13 Synthesis of 1,3-diphenyl-5,5-di(2-pyridyl)-∆ -1,2,4-triazolin 221
25.14 223 Synthesis of 1,3-diphenyl-5,5-di(4-acetophenyl)-∆
6 Experimental part: methods 227
6.1 Removal of moisture from a flask prior to water sensitive reactions 227
6.2 Soxhlet extraction 227
6.3 Melting point measurement 228
6.4 Elemental analysis 228
6.5 HCl gas generation 228
6.6 Purification of the chemicals 228
7
6.6.1 Dibenzoyl peroxide (BPO) (10) 228
6.6.2 Water 228
6.6.3 Monomers 228
6.6.4 2,2'-Azobis-iso-butyronitrile (AIBN) (9) 229
6.7 Gravimetrical determination of monomer conversion 230
6.8 GC determination of monomer conversion 230
6.9 Recognition of triazolin spots on TLC plates 232
6.10 Polymer syntheses 232
6.11 Block copolymer synthesis 232
6.12 “Freeze-thaw” technique 233
6.13 Determination of molecular weights of polymers 233
6.14 HPLC 233
6.15 Mass spectroscopy 233
6.16 NMR 234
6.17 ESR 234
6.18 UV-Vis spectroscopy 234
6.19 Polymerizations in supercritical CO 234 2
7 Abbreviations & remarks 235
8 Acknowledgements237
238 9 Supplementary information
9.1 Incomplete syntheses 238
9.1.1 Synthesis of 1,3–diphenyl-5,5-di-(4{2-[2-(2-methoxy-ethoxy)-ethoxy]-
238
2ethoxy}phenyl)-∆ -1,2,4-triazolin
9.1.2 Synthesis of 1´,3´,1´´,3´´-tetraphenyl-dispiro(9,10-dihydroantracene-
241
2[9.5´,10.5´´]-di-(∆ -1,2,4-triazolin)
9.2 Polymerization in supercritical CO 243 2
9.3 Datasheets for polymerization experiments 244
10 Biography 250




8
1. State of the art

1.1. Polymer chemistry

1.1.1. Introduction

Between 1913 and 1915, several reports on the self-condensation of butadiene came from
1,2,3the group of Lebedev. The products obtained were thought to be cyclic dimers of butadiene,
but Lebedev also proposed the possible existence of long chains consisting of butadiene units. In
41920, Staudinger published a paper, in which the polystyrene structure formed by long linear
chains of styrene blocks; similarly, the paraformaldehyde structure of repeating oxymethylene
units was first proposed. This was one of the first ideas, which laid the ground for the
contemporary understanding of polymer structures. Molecules able to add to other molecules of
the same kind to form condensation products with relatively high molecular weight and a
repeating molecular structure are known as monomers.
5The wider scientific community did initially not accept these ideas. Due to incorrect
propositions and erroneous experimental data, the essentially correct concept of Staudinger was
disregarded. However, Staudinger continued the development of his hypothesis and, in 1929,
offered the new idea of the existence of two types of polymer structures: linear polymers and
6networks. The structure of the polymer strongly influences the properties of the polymer such as
solubility, resistance to mechanical shock, and others. After 24 years, the works of Staudinger
7obtained recognition with the award of Nobel Prize for Chemistry in 1953. Subsequently, work
by Carothers, Kuhn, Guth, Mark, and others completely changed generally accepted views in the
field of the polymer science.
Since that time, many new ideas have been brought into polymer science, but the initial
concept that polymers are long chains consisting of many repeating (monomeric) units remains.
New techniques have been developed to enable researchers to visualize and investigate even
8single molecules. Direct observations of macromolecules such as DNA or even smaller objects