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Ring‐opening polymerization of ε‐caprolactone by a new yttrium complex: Y[2,2′‐ethylidene‐bis(4,6‐di‐ tert ‐butylphenoxy)] 2 (ethylene glycol dimethyl ether)Na(ethylene glycol dimethyl ether) 3
Author(s) -
Wu Guangming,
Liu Jiachu,
Sun Weilin,
Shen Zhiquan,
Ni Xufeng
Publication year - 2010
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.2708
Subject(s) - ethylene glycol , polymerization , ring opening polymerization , polymer chemistry , chemistry , yttrium , caprolactone , ether , bimetal , materials science , organic chemistry , polymer , oxide
The main aims of the work reported here were to synthesize and characterize a new 2,2′‐ethylidene‐bis(4,6‐di‐ tert ‐butylphenol) (EDBPH 2 )‐based bimetal yttrium complex, Y(EDBP) 2 (DME)Na(DME) 3 (1c; where DME is ethylene glycol dimethyl ether), which was employed as an efficient initiator for the ring‐opening polymerization of ε‐caprolactone (ε‐CL). From single‐crystal X‐ray diffraction, the solid structure of this new bimetal initiator was well established. Experimental results show that 1c initiates the ring‐opening polymerization of ε‐CL to afford poly(ε‐CL) with a narrow molecular weight distribution ( M w / M n = 1.09–1.36, 65 °C). Based on an in situ NMR study, a plausible coordination–insertion mechanism is then proposed. The bimetal complex 1c can be used as an initiator for the ring‐opening polymerization of ε‐CL with some living characteristics. A study of the mechanism reveals that DME displacement in 1c by ε‐CL is involved in the initiation process and the propagation may proceed through three pathways by NaO insertion or YO insertion. Copyright © 2009 Society of Chemical Industry