Low-temperature and purification-free stereocontrolled ring-opening polymerisation of lactide in supercritical carbon dioxide

Simon P. Bassett, Andrew D. Russell, Paul McKeown, Isabel Robinson, Thomas R. Forder, Vincenzo Taresco, Matthew G. Davidson, Steven M. Howdle

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)

Abstract

A stereoselective, solvent-free ring-opening polymerisation (ROP) of lactide (LA) in supercritical carbon dioxide (scCO2) is reported for the first time. The key aim is to exploit scCO2 to lower the temperature of traditional melt polymerisations, lowering the energy requirement and leading to cleaner polymeric materials. We have utilised a zirconium amine-trisphenolate initiator-stereoselective catalyst [(iPrO)Zr(OPh(tBu)2-CH2)3N] to yield highly heterotactic poly(lactide) (PLA) homopolymer (Pr = 0.74-0.84) from rac-LA, demonstrating control of the PLA microstructure in scCO2. In addition, high monomer conversion (86-93%) was achieved in short reaction time (1 h), affording poly(lactide) with a very low degree of transesterification and narrow molecular weight distribution. Most importantly, all the reactions were performed at only 80 °C, almost 100 °C lower than the conventional melt process (typically performed at 130-180 °C), representing a very significant potential energy saving.

Original languageEnglish
Pages (from-to)2197-2202
Number of pages6
JournalGreen Chemistry
Volume22
Issue number7
Early online date11 Mar 2020
DOIs
Publication statusPublished - 7 Apr 2020

ASJC Scopus subject areas

  • Environmental Chemistry
  • Pollution

Fingerprint Dive into the research topics of 'Low-temperature and purification-free stereocontrolled ring-opening polymerisation of lactide in supercritical carbon dioxide'. Together they form a unique fingerprint.

Cite this