Issue 40, 2020

Functionalization of polyisoprene and polystyrene via reactive processing using azidoformate grafting agents, and its application to the synthesis of dioxaborolane-based polyisoprene vitrimers

Abstract

Vitrimers incorporating dioxaborolane covalent links are permanent polymeric networks that combine the processability of thermoplastics with the thermomechanical and chemical resistance of thermosets. Transforming existing polymers into vitrimers via melt processing, a green and economical process, is a significant challenge that would greatly facilitate the development of these materials. In this study, we investigate the potential of azidoformate derivatives to functionalize and/or crosslink diene- and vinyl-based polymers with dioxaborolane moieties. To this aim, two functional azidoformate grafting agents were prepared, and their efficiency to functionalize polystyrene and polyisoprene via compression molding and reactive extrusion was assessed. Grafting yields superior to 50 and 75% could be obtained for polystyrene and polyisoprene, respectively. Polyisoprene was then transformed into a vitrimer by reactive extrusion, eitheir in the presence of a mono-azidoformate dioxaborolane and subsequent crosslinking with a bis-dioxaborolane, or in a single step using a bis-azidoformate dioxaborolane crosslinker. In particular, the latter appraoch allowed preparation of vitrimers that relax stress at elevated temperatures, show excellent creep resistance at room temperature and present good mechanical properties. While highly insoluble in THF, these vitrimers could be entirely de-crosslinked by selective diolysis of the dynamic dioxaborolane crosslinks, opening a simple and efficient route to chemical recycling of polyisoprene elastomers. The mechanical recycling of these vitrimers was also investigated over multiple cycles. Polyisoprene vitrimers could be efficiently recycled once, but their mechanical properties significantly dropped after the first recycling cycle, due to the oxidative degradation of the polyisoprene chains during reprocessing.

Graphical abstract: Functionalization of polyisoprene and polystyrene via reactive processing using azidoformate grafting agents, and its application to the synthesis of dioxaborolane-based polyisoprene vitrimers

Supplementary files

Article information

Article type
Paper
Submitted
31 yan 2020
Accepted
25 avq 2020
First published
04 sen 2020

Polym. Chem., 2020,11, 6479-6491

Functionalization of polyisoprene and polystyrene via reactive processing using azidoformate grafting agents, and its application to the synthesis of dioxaborolane-based polyisoprene vitrimers

A. Breuillac, F. Caffy, T. Vialon and R. Nicolaÿ, Polym. Chem., 2020, 11, 6479 DOI: 10.1039/D0PY00164C

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