Issue 14, 2015

Methods to prepare quaternary ammonium groups-containing alternating poly(chlorotrifluoroethylene-alt-vinyl ether) copolymers

Abstract

The radical copolymerisation of electron-acceptor chlorotrifluoroethylene (CTFE) with electron-donor vinyl ethers (VEs) produced poly(CTFE-alt-VE) alternating fluorinated copolymers with a high content of functional groups. This article describes methods to synthesise poly(CTFE-alt-VE) copolymers that bear ammonium-groups insensitive to Hofmann degradation. Direct preparation and post-polymerisation functionalisation methods are presented. First, the radical copolymerisation of CTFE with a tertiary amine-carrying vinyl ether led to low molecular weight-copolymers with an imperfect structure. That copolymerisation and the quaternisation of the amino groups using methyl iodide were however accompanied by side reactions, including transfer reactions and significant loss of functionality. In contrast, the second strategy dealt with the post functionalisation of an alternated poly(CTFE-alt-2-chloroethyl vinyl ether) copolymer. Halogen exchange of poly(CTFE-alt-CEVE) copolymers was carried out using the efficient Finkelstein reaction. Then, the nucleophilic substitution of the iodine atoms on the obtained poly(CTFE-alt-IEVE) copolymer led to a poor yield of functionalisation and was accompanied by a substantial amount of side reactions. Then, the iodine atoms in poly(CTFE-alt-IEVE) copolymers were chemically changed quantitatively into azides (especially from microwave activation) and the resulting azido-containing copolymer was reacted with 1-dimethylamino-2-propyne. An optimisation of this Huisgen's or thermal cycloaddition showed that (i) a copper catalyst led to cross-linked copolymers, (ii) whereas in the absence of the copper catalyst, the cycloaddition was slow and only converted ca. 60% of the azides; (iii) then, microwave activation led to high yield in a few minutes. Dimethylamino groups were inserted onto the copolymeric backbone and subsequently quaternised using iodomethane efficiently. Such copolymers, potentially resistant to alkaline media and able to promote hydroxide anion conduction, may exhibit interesting properties as a component of solid alkaline fuel cell membranes.

Graphical abstract: Methods to prepare quaternary ammonium groups-containing alternating poly(chlorotrifluoroethylene-alt-vinyl ether) copolymers

Supplementary files

Article information

Article type
Paper
Submitted
25 Aug 2014
Accepted
23 Dec 2014
First published
23 Dec 2014

RSC Adv., 2015,5, 10243-10253

Author version available

Methods to prepare quaternary ammonium groups-containing alternating poly(chlorotrifluoroethylene-alt-vinyl ether) copolymers

G. Couture, V. Ladmiral and B. Améduri, RSC Adv., 2015, 5, 10243 DOI: 10.1039/C4RA09238D

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