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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

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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

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Outline

Introduction

Motivation

Experiment

Result and Discussion

Summary

Polymerization of Divinylbenzene

Cross-linked or Star-branched

Polymer

Soluble Polymer Stable Living Polymer

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Introduction

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Polymerization of Divinylbenzene

Isomers

Crosslinked Polymer

Insoluble Polymer

Ion exchange resin

Column – Packing agents

Pendent vinyl group

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Cross-linked Polymer

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D. J. Worsfold, Macromolecules, 1970, 3, 514

Flory-Huggins Theory Gel Point

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L. J. Fetters, Macromolecules, 1978 11, 899

Star-branched PolymerPoly(isoprenyl) – lithium + m-divinylbenzene

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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)

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Pendent vinyl groupContent

Charge Transfer (DPA)

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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

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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

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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

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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

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Effect of 18-Crown-6, and P4-tBu

18-Crown-6 P4-tBu

Strongly coordinate with K+

Steric bulkiness

Soluble polymer but PDI large

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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

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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 ↓

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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

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Stabilization of Chain-End Anion

1,1-diphenylethylene

tert-butyl methacrylate-78 for 3hr (enolate anion)℃

-78 for 5hr℃ (diphenyl)

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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

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Thank you for your attention !