Issue 45, 2021

Role of thiol oxidation by air in the mechanism of the self-initiated thermal thiol–ene polymerization

Abstract

A spontaneous thiol–ene polymerization has been reported in the literature for a broad range of monomers, generally under conditions avoiding solvents, heating and the intentional formation of radicals. In the search for a mechanism accounting for the self-initiated thiol–ene polymerization, this study demonstrates the significant role played by thiyl radicals produced by thiol oxidation through dissolved atmospheric oxygen in the thiol–ene mixture. To determine the factors underlying the reactivity, self-initiated polymerization kinetics, thiol solvation and the nature of initiating radicals are studied by means of various techniques including real-time FTIR, 1H NMR spectroscopy and spin-trapping experiments. Our data support that the driving force for thiol air oxidation is the polarization of the S–H bond. Thiol substituents with electron-withdrawing properties and/or hydrogen-bonded thiol–solvent (or thiol–alkene) complexes favor self-initiation by increasing S–H bond polarization, thereby easing the electron transfer to molecular oxygen.

Graphical abstract: Role of thiol oxidation by air in the mechanism of the self-initiated thermal thiol–ene polymerization

Supplementary files

Article information

Article type
Paper
Submitted
28 ก.ย. 2564
Accepted
28 ต.ค. 2564
First published
29 ต.ค. 2564

Polym. Chem., 2021,12, 6594-6605

Role of thiol oxidation by air in the mechanism of the self-initiated thermal thiol–ene polymerization

C. M. Q. Le, F. Morlet-Savary and A. Chemtob, Polym. Chem., 2021, 12, 6594 DOI: 10.1039/D1PY01301G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements