Polymerization of Lactide Catalyzed by Diketiminato Iron (II) Alkoxide Complex

Lactide polymerization were carried out by using diketiminato iron (II) alkoxide complexes HC(C(CH3)N-2,6-iPr2C6H3)2FeOiPr as catalyst. The iron (II) alkoxide complex bearing bulky isopropyl ortho substituents showed moderate activity for the rac-lactide polymerization, and gave the polylactide (PLA) with high molecular weight. In the microstructures of polymers generated with the iron (II) catalyst, no stereoslective polymerization of rac-lactide has been detected. Results have shown that the conversion of lactide depend on the iron complex/monomer feed ratio and the reaction temperature.

[1]  Xuesi Chen,et al.  Enolic schiff base aluminum complexes and their catalytic stereoselective polymerization of racemic lactide. , 2008, Chemistry.

[2]  J. Gallucci,et al.  Complexities in the ring-opening polymerization of lactide by chiral salen aluminum initiators. , 2008, Inorganic chemistry.

[3]  M. Chisholm,et al.  Concerning the relative importance of enantiomorphic site vs. chain end control in the stereoselective polymerization of lactides: reactions of (R,R-salen)- and (S,S-salen)-aluminium alkoxides LAlOCH2R complexes (R = CH3 and S-CHMeCl). , 2005, Chemical communications.

[4]  Xuesi Chen,et al.  Stereoselective polymerization of rac-lactide using a monoethylaluminum Schiff base complex. , 2004, Biomacromolecules.

[5]  J. Feijen,et al.  Controlled and stereoselective polymerization of lactide: kinetics, selectivity, and microstructures. , 2003, Journal of the American Chemical Society.

[6]  M. Chisholm,et al.  Conformational effects in β-diiminate ligated magnesium and zinc amides. Solution dynamics and lactide polymerization , 2003 .

[7]  J. Feijen,et al.  [(salen)Al]-Mediated, controlled and stereoselective ring-opening polymerization of lactide in solution and without solvent: synthesis of highly isotactic polylactide stereocopolymers from racemic D,L-lactide. , 2002, Angewandte Chemie.

[8]  Andrew J. P. White,et al.  A well-defined iron(II) alkoxide initiator for the controlled polymerisation of lactide , 2002 .

[9]  J. Gallucci,et al.  Coordination chemistry and reactivity of monomeric alkoxides and amides of magnesium and zinc supported by the diiminato ligand CH(CMeNC(6)H(3)-2,6-(i)Pr(2))(2). A comparative study. , 2002, Inorganic chemistry.

[10]  M. Hillmyer,et al.  Mechanistic comparison of cyclic ester polymerizations by novel iron(III)-alkoxide complexes: single vs multiple site catalysis. , 2002, Journal of the American Chemical Society.

[11]  G. Coates,et al.  Stereochemistry of lactide polymerization with chiral catalysts: new opportunities for stereocontrol using polymer exchange mechanisms. , 2002, Journal of the American Chemical Society.

[12]  David R. Moore,et al.  Polymerization of lactide with zinc and magnesium beta-diiminate complexes: stereocontrol and mechanism. , 2001, Journal of the American Chemical Society.

[13]  Geoffrey W. Coates,et al.  Stereoselective ring‐opening polymerization of rac‐lactide with a single‐site, racemic aluminum alkoxide catalyst: Synthesis of stereoblock poly(lactic acid) , 2000 .

[14]  A. Attygalle,et al.  Single-Site Catalysts for Ring-Opening Polymerization: Synthesis of Heterotactic Poly(lactic acid) from rac-Lactide , 1999 .

[15]  N. Spassky,et al.  Highly stereoelective polymerization of rac‐(D,L)‐lactide with a chiral schiff's base/aluminium alkoxide initiator , 1996 .

[16]  Dirk W. Grijpma,et al.  Lewis acid catalyzed polymerization of L-lactide. Kinetics and mechanism of the bulk polymerization , 1992 .

[17]  J. M. Smith,et al.  Tuning metal coordination number by ancillary ligand steric effects: synthesis of a three-coordinate iron(II) complex. , 2001, Chemical communications.

[18]  A. White,et al.  A well defined tin(II) initiator for the living polymerisation of lactide , 2001 .

[19]  M. Chisholm,et al.  Monomeric metal alkoxides and trialkyl siloxides: (BDI)Mg(OtBu)(THF) and (BDI)Zn(OSiPh3)(THF). Comments on single site catalysts for ring-opening polymerization of lactides , 2001 .