Premium
Highly Active N,O Zinc Guanidine Catalysts for the Ring‐Opening Polymerization of Lactide
Author(s) -
Schäfer Pascal M.,
Fuchs Martin,
Ohligschläger Andreas,
Rittinghaus Ruth,
McKeown Paul,
Akin Enver,
Schmidt Maximilian,
Hoffmann Alexander,
Liauw Marcel A.,
Jones Matthew D.,
HerresPawlis Sonja
Publication year - 2017
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201701237
Subject(s) - lactide , polymerization , dispersity , ring opening polymerization , catalysis , zinc , polymer chemistry , monomer , chemistry , solvent , organic chemistry , polymer
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 [ZnCl 2 (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 complex C1 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.