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Living Anionic Polymerization of
1,4-Divinylbenzene and Its Isomers
Shunsuke Tanaka, Masayoshi Matsumoto, Raita Goseki, Takashi Ishizone, and Akira Hirao,
Macromolecules, 2013, 46, 146
103 學年度台灣大學高分子科學與工程學系 高分子合成特論
Advisor : Professor Guey-Sheng LiouReporter : Tzu-Tien Huang
Date : 2014 / 12 / 26
2
103 學年度台灣大學高分子科學與工程學系 高分子合成特論
Advisor : Professor Guey-Sheng LiouReporter : Tzu-Tien Huang
Date : 2014 / 12 / 26
3
Outline
Introduction
Motivation
Experiment
Result and Discussion
Summary
Polymerization of Divinylbenzene
Cross-linked or Star-branched
Polymer
Soluble Polymer Stable Living Polymer
4
Introduction
5
Polymerization of Divinylbenzene
Isomers
Crosslinked Polymer
Insoluble Polymer
Ion exchange resin
Column – Packing agents
Pendent vinyl group
6
Cross-linked Polymer
6
D. J. Worsfold, Macromolecules, 1970, 3, 514
Flory-Huggins Theory Gel Point
7
L. J. Fetters, Macromolecules, 1978 11, 899
Star-branched PolymerPoly(isoprenyl) – lithium + m-divinylbenzene
8
Growing carbanion ↑ → life time ↓ (Chain transfer by DPA) Reactivity Pendent vinyl groups < DVB monomerGrowing carbanion ↑ → Reactivity ↓(Stabilized 10 π -conjugation.)
Soluble Polymer
Teiji Tsuruta, J. MACROMOL. SCI.-CHEM., 1989, A26(8), 1043
Lithium diisopropylamide (LDA)
9
Pendent vinyl groupContent
Charge Transfer (DPA)
10
Stable Living Polymer
Akira Hirao, Macromolecules, 2011, 44, 4579
In THF at -78 for 1 ℃min
Initiator – Oligo ( α-methylstyryl ) lithium ( sec-BuLi / α-MeSt )Additive - KOBut
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Initiator sec-BuLi sec-BuLi/α-MeSt /KOBut
sec-BuLi/α-MeSt /KOBut
sec-BuLi/α-MeSt /KOBut
12 eq 12 eq 5 eq
DVB-5DVB-4DVB-3DVB-1
Anionic Polymerization of 1 in THF at 78 C for 1 min
SEC profiles of polymers
12
Motivation
Soluble Polymer
High yield
High molecular weightSmall PDI
Stable Living Polymer
Polymerization of Divinylbenzene
Avoid Crossliked or gel(Pendent vinyl group reation)
Time vs TemperaturePendent vinyl group reactivity
Expected Polymerization
13
Experiment
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Synthesis of 1,4-Divinylbenzene
(1)
106 g
THF
1500 ml
(2)
321 gN2
R.T.
stir 20 min
(3) or (4) or (5) / THF
59.6 g / 500 mlTemp ¡Õ 40¢J
R.T.
stir 1 hr
H2O / Ice Extraction (n-hexane)
Dry1200 ml / 800ml
Scheme
Procedure
CH3
OKH3CH3C
P+H3CBr-
O
O
HO
OH
O O
HO OH
O O
HO OH
THF, 40 ¢J
(8)
(7)
(6)
(5)
(4)
(3)
(2)(1)
Potassiumtert - butoixde
MethyltriphenylPhosphonium
Bromide
Phthaladehyde Divinylbenzene
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Preparation of Additives
R OH
Phenol or Alochol
0.3 M THF
Solution A Solution B
K
Potassium naphthalenide
0.5 ~ 0.8 M THF
THF at −78 ℃ Colorimetric
titration
0.05 ~ 0.1 MPotassium Alkoxides
and Phenoxides
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PolymerizationSurrounding - THF -78℃
THF -95 ℃
Initiator - Oligo ( α-methylstyryl ) lithium ( sec-BuLi / α-MeSt )
Additive - Potassium Alkoxides and Phenoxides
Monomer - 1,4 – Divinylbenzene
1,3 – Divinylbenzene
1,2 - Divinylbenzene
Terminator - Methanol
N2
N2
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Result and Discussion
18
Previous - KOBut
Akira Hirao, Macromolecules, 2011, 44, 4579
Atom size : K+ > Li+
Salt effect > Solvation (Abound of K+ )
( ion-pair > ion-dissociated )
Steric bulkiness (tert-Butyl)
Main Chain ↑ → Pendant vinyl group reativity ↓
(The vinyl group of main chain is electron donating)
DVB-5DVB-4DVB-3DVB-1
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Effect of Metal Alkoxides - Metal
x
[Initiator] = 2~3 ×10-3 M ; [Monomer] = 0.2~0.9 M
LiOBut NaOBut KOBut
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Effect of Potassium AlkoxidesReacting alcohol with potassium naphthalenide in THF at −78 (10 eq)℃
CR
R
OR
OR
Acetal Oxygen Atom
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Effect of Potassium AlkoxidesReacting alcohol with potassium naphthalenide in THF at −78 (10 eq)℃
Less of steric hindrance
pKa small
→ The ion is stable
→ Ion-dissociated > Ion-pair
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Effect of Potassium Phenoxides and Potassium Pivalate Potassium Phenoxides Potassium Pivalate
Phenol pKa=10 < Alcohol pKa=16~18
Pivalic acid
pKa= 5 → 70%PDI = 1.04
23
Effect of 18-Crown-6, and P4-tBu
18-Crown-6 P4-tBu
Strongly coordinate with K+
Steric bulkiness
Soluble polymer but PDI large
24
Summary of Additive
Soluble Polmer
Small PDI
Potassium Alkoxides
Potassium Phenoxides
Potassium Salt
(Pivalic acid)
Reacting in THF at −78 ℃
Steric bulkiness
Increase the distance between chain end anion and pendent vinyl
group.
Basicity
Effect the ion stability
(Compare the Interaction between Ion-dissociated and ion-pair
Not Absolutely
25
Effect of Temperature and Polymerization Time In THF at −78 for 5 min ℃
Mn ↑ PDI↑
In THF at −95 for 10~30 ℃min
30 min 10 min 15 min
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Anionic Polymerization of 1,2- and 1,3-Divinylbenzenes
1,2 - Divinylbenzene 1,3 - Divinylbenzene
Bulky group protect ↓
27
1,4 - Divinylbenzene
1,2 - Divinylbenzene
1,3 - Divinylbenzene
Anionic Polymerization of Divinylbenzenes Isomers
10 π, 5 resonace
10 π, 5 resonace
8 π, 4 resonace
1,4 and 1,2 - Divinylbenzene is more stable than 1,3 - Divinylbenzene
28
Stabilization of Chain-End Anion
1,1-diphenylethylene
tert-butyl methacrylate-78 for 3hr (enolate anion)℃
-78 for 5hr℃ (diphenyl)
29
Summary
Soluble Polymer Small PDI High Yield Stable Living
Polymer 30
Additive
Reaction Time and Temperature
Potassium Alkoxides
Potassium Phenoxides
Potassium Salt
(Pivalic acid)
In THF at −78 for 1 min ℃ In THF at −95 for 10~30 min ℃
Divinylbenzenes Isomers
1,4 and 1,2 - Divinylbenzene is more stable than 1,3 - Divinylbenzene
Stabilization of Chain-End Anion
tert-butyl methacrylate
1,1-diphenylethylene
31
Thank you for your attention !