Post-Polymerisation Oxyfunctionalisation of Styrene and Butadiene-Based (Co-)Polymers using a Homogeneous Manganese Catalyst

Abstract

Post-polymerisation modification of commodity hydrocarbon-based polymers provides access to functional polymers not readily available through bottom-up synthesis methods. Here, we demonstrate the oxyfunctionalisation of different styrenic and rubbery (co-)polymers using a well-established and robust manganese-based homogeneous catalyst, MnTACN, a 1,4,7-trimethyl-1,4,7-triazacyclononane ligand bearing di-nuclear tri-μ-oxo bridged Mn(IV) compound, and hydrogen peroxide as green oxidant. Using various grades of polystyrene (PS) and polybutadiene (PBD), we successfully oxyfunctionalised the polymer backbones with alcohol (PS and PBD), ketone (PS) and epoxide (PBD) functional groups. Under optimised conditions, total functionalisation degrees up to 5% for PS and 18% for PBD can be achieved. Next to the homopolymers, we also show oxyfunctionalisation degrees as high as 11%, of the butadiene-derived part of a styrene-butadiene-styrene block-co-polymer (SBS). These results underscore the versatility of a single catalytic system for the oxyfunctionalisation of various C-H bonds as well as the C=C bonds found in these commodity hydrocarbon polymers. Detailed analysis of the oxidised polymers before and after subsequent oxidative cleavage of the installed diol moieties on the PBD backbone suggest that the functional groups are randomly spaced along the polymer backbone. Moreover, this second oxidative cleavage also offers the possibility to selectively break down the polymer backbone after oxyfunctionalisation into a mixture of dialdehydes oligomers consisting of 4 up to 32 monomeric units. For PBD and low/mid Mw PS, oxyfunctionalisation coincided with minimal backbone cleavage or crosslinking, as evidenced by gel permeation chromatography (GPC). For the high molecular weight PS samples and SBS, GPC analysis suggests that backbone cleavage is in contrast more pronounced upon oxyfunctionalisation. The thermal properties of the oxyfunctionalised materials are largely unchanged, with decomposition temperatures decreasing with increasing functionalisation degrees, but overall remaining in the high thermal stability regime.

Supplementary files

Article information

Article type
Paper
Submitted
01 Jun 2025
Accepted
11 Jul 2025
First published
11 Jul 2025
This article is Open Access
Creative Commons BY license

Faraday Discuss., 2025, Accepted Manuscript

Post-Polymerisation Oxyfunctionalisation of Styrene and Butadiene-Based (Co-)Polymers using a Homogeneous Manganese Catalyst

M. Otten, J. Hendriks, N. Kalános, A. Thevenon and P. C. A. Bruijnincx, Faraday Discuss., 2025, Accepted Manuscript , DOI: 10.1039/D5FD00093A

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements