Converting Step growth polymerization to chain growth

7/30/2019 Converting Step growth polymerization to chain growth

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Converting Step-Growth to ChainGrowth Condensation Polymerization

April FogelDahlia Amato

Akihiro Yokoyama & Tsutomu YokozawaMacromolecules, 2007

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Authors Akihiro Yokoyama

Associate Professor of Material and Life Chemistry atKanagawa University, Japan

H-index : 20 PhD in Pharmaceutical Science from University of Tokyo

Postdoctoral research at Osaka Prefecture University

Interests: Development of novel polymerization

Syntheses of polymers and supermolecules with 3Dstructure

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Authors Tsutomu Yokozawa

Professor at Dept. of Material & Life Chemistry Kanagawa

University, Japan

H-index : 18

PhD in Organic Chemistry from Tokyo Institute of Technology

Visiting Scientist at University of Illinois at Urbana-Champaign

Researcher for PRESTO JST

Interests: Controlled synthesis of polymers

Supramolecular chemistry of polymers, and dynamic

covalent chemistry

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Department of Materials and Life Chemistry

Kanagawa University, Japan

Graduate Program

13 research groups

3 courses or specialized fields

Resources

Energy and the environment

Structural and functional materials and bimolecular

engineering

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Step growth: Polymerization that occurs in a stepwise manner

between the function groups of monomers

Introduction

Monomer A

Monomer B

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Step Growth Polymer Characteristics Definite functionality ofend group

Strong intermolecular interaction in the

backbone

High thermal and chemical resistance

PDI close to 2 (too broad distribution).

Hard to control MW

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Living Polymerization Easy control MW

Narrow PDI

Various shapes and properties

Applicable only to addition to vinyl monomers,

ring opening of cyclic monomers

Not: polycondensation

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Differences in step and chain growth

(1) Amato, D. LATENT CYSTEINE RESIDUES FROM POLYMERS PREPARED VIA FREE AND CONTROLLED RADICAL POLYMERIZATIONS, California Polytechnic State University, San Luis Obispo.

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Differences in step and living Monomer in living is unreactive with other

monomers!

Only active site can be polymerized.

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*

Active Site Monomer


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Big Idea

If step growth monomers could only react

with propagating polymer then step growthwould become similar to chain growth!

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Their Goal Synthesize condensation polymers in chain

growth mannerfrom an initiator

Posses controlled MW Narrow PDI and definite end group

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Approach1. Change substituent effect

2. Selective transfer of catalysts to polymer end

group3. Transfer monomer from an unpolymerizable

solid phase to polymerizable solution phase

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Substituent effect

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Resonance Effect

Typical step growth

Yokozawa, T.; Asai, T.; Sugi, R.; Ishigooka, S.; Hiraoka, S. Chain-Growth Polycondensation for Nonbiological Polyamides of Defined Architecture.

J. Am. Chem. Soc. 2000, 122, 83138314.

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Applications

Kevlar block co-polymer

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Inductive Effect Polyamide

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Substituent Effect - Polyester

Yokoyama, A.; Iwashita, K.-I.; Hirabayashi, K.; Aiyama, K.; Yokozawa, T. Investigation of aromatic polyester synthesis by the chain-growth polycondensation method. Macromolecules 2003, 36, 43284336.17


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Substituent Effect - Polyester

*5:1 Monomer : Initiator; using CH2Cl2, R.T.

Yokoyama, A.; Iwashita, K.-I.; Hirabayashi, K.; Aiyama, K.; Yokozawa, T. Investigation of aromatic polyester synthesis by the chain-growth polycondensation method. Macromolecules 2003, 36, 43284336.

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Inductive Effect - Polyester

5:1 (M:I) 10:1 (M:I) 20:1 (M:I)

Yokoyama, A.; Iwashita, K.-I.; Hirabayashi, K.; Aiyama, K.; Yokozawa, T. Investigation of aromatic polyester synthesis by the chain-growth polycondensation method. Macromolecules 2003, 36, 43284336.

Increased transesterification at higher M:I leads to decreased control

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Substituent Effect - Polyether

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Substituent Effect - Polyether Higher molecular weight polymer is not soluble in the

polymerization solvent

Suzuki, Y.; Hiraoka, S.; Yokoyama, A.; Yokozawa, T. Chain-Growth Polycondensation for Aromatic Polyethers with Low Polydispersities: Living Polymerization Nature in Polycondensation.

Macromolecules 2003, 36, 47564765.

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Catalyst-Transfer Condensation

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Catalyst-Transfer Condensation

Yokoyama, A.; Miyakoshi, R.; Yokozawa, T. Chain-growth polymerization for poly (3-hexylthiophene) with a defined molecular weight and a low polydispersity. Macromolecules 2004, 37, 11691171.

Polymerization

is fast!

Still living!

Polymerization of2 with 0.4 mol %

of Ni(dppp)Cl2 in THF at room

temperature ([2]0 ) 0.12 M)

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Biphasic System

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Biphasic System

Yokozawa, T.; Suzuki, H. Condensative chain polymerization in solid-liquid phase. Synthesis of polyesters with a defined molecular weight and a narrow molecular weight distribution by polycondensation. J.

Am. Chem. Soc. 1999, 121, 1157311574.

Mn andMw/Mn values of polymerization obtained with

18-crown-6 in acetone at 25 C

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Summary

Chain-growth condensation polymerization

achieved through:

Substituent effect-assistance

Aromatic polyamides

Aromatic polyesters

Aromatic polyethers

Intramolecular catalyst transfer

Biphasic system

Future work Chain-growth condensation polymerization with

nonaromatic monomers 26

Converting Step growth polymerization to chain growth

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