Open AccessNeodymium‐based catalysts bearing phosphate ligands for ring‐opening polymerization of ɛ‐caprolactone
Author(s) -
Ren Yixin,
Kularatne Ruvanthi N.,
Miller Justin T.,
Polderman Stefanie T.,
Vo Trinh D.,
Biewer Michael C.,
Stefan Mihaela C.
Publication year - 2018
Publication title -
journal of polymer science part a: polymer chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.768
H-Index - 152
eISSN - 1099-0518
pISSN - 0887-624X
DOI - 10.1002/pola.29010
Subject(s) - chemistry , polymer chemistry , ring opening polymerization , dispersity , caprolactone , benzyl alcohol , catalysis , polymerization , monomer , ligand (biochemistry) , copolymer , phosphate , polymer , organic chemistry , biochemistry , receptor
Neodymium‐based catalysts coordinated with phosphate ligands (NdCl 3 ·3L), where L = triethyl phosphate (TEP) or tris(2‐ethylhexyl) phosphate (TEHP), were synthesized. The ring‐opening polymerizations (ROP) of ɛ‐caprolactone (ɛ‐CL) with these catalysts in the presence of benzyl alcohol initiator were performed, yielding polymers with well‐defined molecular weights and relatively narrow polydispersity index (PDI = 1.22–1.65). In situ NMR analysis of the reaction between NdCl 3 ·3TEP and benzyl alcohol indicated that ROP proceeds through a coordination‐insertion mechanism. The end groups of the resultant polymers were determined using MALDI‐ToF mass spectrometry and NMR spectroscopy. The quasi‐living nature of this catalytic system was demonstrated by kinetic studies and the successful synthesis of the block copolymer poly(ɛ‐caprolactone)‐ block ‐poly( l ‐lactide) by sequential monomer addition. Kinetic studies revealed that the catalyst with the bulkier TEHP ligand increased the rate of ROP of ɛ‐CL as compared to the TEP ligand. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56 , 1289–1296