Issue 18, 2019

Tuning a robust system: N,O zinc guanidine catalysts for the ROP of lactide

Abstract

Non-toxic, highly active and robust complexes are the holy grail as ideal green catalysts for the polymerisation of biorenewable and biodegradable polylactide. Four new zinc guanidine complexes [ZnCl2(TMG4NMe2asme)], [ZnCl2(TMG5Clasme)], [ZnCl2(TMG5Measme)] and [ZnCl2(TMG5NMe2asme)] with different electron-donating and electron-withdrawing groups on the ligand's aromatic backbone have been synthesised. Ligands are derived from low-cost commercially available compounds and have been converted by a three- or four-step synthesis process into the desired ligand in good yields. The compounds have been fully characterised and tested in the ROP of rac-LA under industrially relevant conditions. The complexes are based on the recently published structure [ZnCl2(TMGasme)] which has shown high activity in the polymerisation of lactide at 150 °C. Different substituents in the para-position of the guanidine moiety significantly increase the polymerisation rate whereas positioning substituents in the meta-position causes no change in the reaction rate. With molecular weights over 71 000 g mol−1 being achievable, the best system produces polymers for multiple industrial applications and its polymerisation rate approaches that of Sn(Oct)2. The robust systems are able to polymerise non-purified lactide. The initiation of the polymerisation is suggested to occur due to impurities in the monomer.

Graphical abstract: Tuning a robust system: N,O zinc guanidine catalysts for the ROP of lactide

Supplementary files

Article information

Article type
Paper
Submitted
15 дек 2018
Accepted
29 яну 2019
First published
29 яну 2019

Dalton Trans., 2019,48, 6071-6082

Tuning a robust system: N,O zinc guanidine catalysts for the ROP of lactide

P. M. Schäfer, P. McKeown, M. Fuchs, R. D. Rittinghaus, A. Hermann, J. Henkel, S. Seidel, C. Roitzheim, A. N. Ksiazkiewicz, A. Hoffmann, A. Pich, M. D. Jones and S. Herres-Pawlis, Dalton Trans., 2019, 48, 6071 DOI: 10.1039/C8DT04938F

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