Highly Active N, O Zinc Guanidine Catalysts for the Ring‐Opening Polymerization of Lactide. Issue 18 (19th September 2017)

• Record Type: Journal Article
• Authors: Schäfer, Pascal M.; Fuchs, Martin; Ohligschläger, Andreas; Rittinghaus, Ruth; McKeown, Paul; Akin, Enver; Schmidt, Maximilian; Hoffmann, Alexander; Liauw, Marcel A.; Jones, Matthew D.; Herres‐Pawlis, Sonja
• Is Part Of: ChemSusChem. Volume 10:Issue 18(2017)
• Page Start: 3547
• Page End: 3556
• Publication Date: 2017-09-19
• Subjects: catalysis -- guanidine -- poly(lactide) -- ring-opening polymerization -- zinc; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201701237
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: New zinc guanidine complexes with N, O donor functionalities were prepared, characterized by X‐Ray crystallography, and examined for their catalytic activity in the solvent‐free ring‐opening polymerization (ROP) of technical‐grade rac ‐lactide at 150 °C. All complexes showed a high activity. The fastest complex [ZnCl2 (DMEGasme)] (C1 ) produced colorless poly(lactide) (PLA) after 90 min with a conversion of 52 % and high molar masses ( M w =69 100, polydispersity=1.4). The complexes were tested with different monomer‐to‐initiator ratios to determine the rate constant k p . Furthermore, a polymerization with the most active complexC1 was monitored by in situ Raman spectroscopy. Overall, conversion of up to 90 % can be obtained. End‐group analysis was performed to clarify the mechanism. All four complexes combine robustness against impurities in the lactide with high polymerization rates, and they represent the fastest robust lactide ROP catalysts to date, opening new avenues to a sustainable ROP catalyst family for industrial use. Abstract : Fast and robust ! Four fast robust ring‐opening polymerization (ROP) catalysts polymerize lactide in high yields and good molar masses with potential for industrial application. All four complexes combine robustness against impurities in the lactide with high polymerization rates, and they represent the fastest robust lactide ROP catalysts to date. End‐group analysis was performed to clarify the mechanism.