Undiscovered Potential: Ge Catalysts for Lactide Polymerization

Ruth D. Rittinghaus, Jakub Tremmel, Ales Ruzicka, Christian Conrads, Pascal Albrecht, Alexander Hoffmann, Agnieszka N. Ksiazkiewicz, Andrij Pich, Roman Jambor*, Sonja Herres-Pawlis*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Polylactide (PLA) is a high potential bioplastic that can replace oil-based plastics in a number of applications. To date, in spite of its known toxicity, a tin catalyst is used on industrial scale which should be replaced by a benign catalyst in the long run. Germanium is known to be unharmful while having similar properties as tin. Only few germylene catalysts are known so far and none has shown the potential for industrial application. We herein present Ge complexes in combination with zinc and copper, which show amazingly high polymerization activities for lactide in bulk at 150 degrees C. By systematical variation of the complex structure, proven by single-crystal XRD and DFT calculations, structure-property relationships are found regarding the polymerization activity. Even in the presence of zinc and copper, germanium acts as the active site for polymerizing probably through the coordination-insertion mechanism to high molar mass polymers.

Original languageEnglish
Pages (from-to)212-221
Number of pages10
JournalChemistry: a European journal
Volume26
Issue number1
DOIs
Publication statusPublished - 2 Jan 2020

Keywords

  • bioplastics
  • germanium
  • lactide
  • ring-opening polymerization
  • zinc
  • RING-OPENING POLYMERIZATION
  • UNSUPPORTED SILVER-GERMANIUM
  • ZETA VALENCE QUALITY
  • BOND COVALENT RADII
  • ZINC-COMPLEXES
  • BASIS-SETS
  • STRUCTURAL-CHARACTERIZATION
  • EXPANSION POLYMERIZATIONS
  • EPSILON-CAPROLACTONE
  • ALKOXIDE COMPLEXES

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