Chain Transfer Kinetics of Acid/Base Switchable N-Aryl-N-Pyridyl Dithiocarbamate RAFT Agents in Methyl Acrylate, N-Vinylcarbazole and Vinyl Acetate Polymerization

Keddie, Daniel; Guerrero-Sanchez, Carlos; Moad, Graeme; Mulder, Roger J; Rizzardo, Ezio; Thang, San H

doi:10.1021/ma300616g

Author(s)

Keddie, Daniel

Guerrero-Sanchez, Carlos

Moad, Graeme

Mulder, Roger J

Rizzardo, Ezio

Thang, San H

Publication Date

2012

Abstract

The structures of the "Z" and "R" substituents of a RAFT agent (Z-C(S)S-R) determine a RAFT agent's ability to control radical polymerization. In this paper we report new acid/base switchable N-aryl-N-pyridyl dithiocarbamates (R = -CH₂CN, Z = -N(Py)(Ar)) which vary in substituent at the 4-position of the aryl ring and the use of these to control molecular weight and dispersity. In their protonated form, the new RAFT agents are more effective in controlling polymerization of the more activated monomer, methyl acrylate (MA), whereas in their neutral form they provide more effective control of the polymerization of less activated monomers, N-vinyl carbazole (NVC) and vinyl acetate (VAc). For each polymerization, the apparent chain transfer coefficient (Ctrapp) shows a good correlation with Hammett parameters. Dithiocarbamates with more electron-withdrawing aryl ring substituents have the higher Ctrapp. This demonstrates the influence of polar effects on Ctrapp and supports the hypothesis that the activity of these RAFT agents is determined by the availability of the lone pair of the dithiocarbamate nitrogen.

Citation

Macromolecules, 45(10), p. 4205-4215

ISSN

1520-5835

0024-9297

Link

https://hdl.handle.net/1959.11/12023

Language

en

Publisher

American Chemical Society

Title

Chain Transfer Kinetics of Acid/Base Switchable N-Aryl-N-Pyridyl Dithiocarbamate RAFT Agents in Methyl Acrylate, N-Vinylcarbazole and Vinyl Acetate Polymerization

Type of document

Journal Article

Entity Type

Publication

Author(s)	Keddie, Daniel Guerrero-Sanchez, Carlos Moad, Graeme Mulder, Roger J Rizzardo, Ezio Thang, San H
Publication Date	2012
Abstract	The structures of the "Z" and "R" substituents of a RAFT agent (Z-C(S)S-R) determine a RAFT agent's ability to control radical polymerization. In this paper we report new acid/base switchable N-aryl-N-pyridyl dithiocarbamates (R = -CH₂CN, Z = -N(Py)(Ar)) which vary in substituent at the 4-position of the aryl ring and the use of these to control molecular weight and dispersity. In their protonated form, the new RAFT agents are more effective in controlling polymerization of the more activated monomer, methyl acrylate (MA), whereas in their neutral form they provide more effective control of the polymerization of less activated monomers, N-vinyl carbazole (NVC) and vinyl acetate (VAc). For each polymerization, the apparent chain transfer coefficient (Ctrapp) shows a good correlation with Hammett parameters. Dithiocarbamates with more electron-withdrawing aryl ring substituents have the higher Ctrapp. This demonstrates the influence of polar effects on Ctrapp and supports the hypothesis that the activity of these RAFT agents is determined by the availability of the lone pair of the dithiocarbamate nitrogen.
Citation	Macromolecules, 45(10), p. 4205-4215
ISSN	1520-5835 0024-9297
Link	https://hdl.handle.net/1959.11/12023
Language	en
Publisher	American Chemical Society
Title	Chain Transfer Kinetics of Acid/Base Switchable N-Aryl-N-Pyridyl Dithiocarbamate RAFT Agents in Methyl Acrylate, N-Vinylcarbazole and Vinyl Acetate Polymerization
Type of document	Journal Article
Entity Type	Publication

Chain Transfer Kinetics of Acid/Base Switchable N-Aryl-N-Pyridyl Dithiocarbamate RAFT Agents in Methyl Acrylate, N-Vinylcarbazole and Vinyl Acetate Polymerization

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