ma050600o_si_002.cif (20.23 kB)
Synthesis, Characterization, and Catalytic Studies of Lithium Complexes: Efficient Initiators for Ring-Opening Polymerization of l-Lactide
dataset
posted on 2005-11-15, 00:00 authored by Mao-Lin Hsueh, Bor-Hunn Huang, Jincai Wu, Chu-Chieh LinThe reaction of 2,2‘-ethylidenebis(4,6-di-tert-butylphenol) (EDBP-H2) with nBuLi in tetrahydrofuran (THF), giving [(EDBP-H)Li(THF)3] (1) in high yield. However, the reaction of EDBP-H2
with nBuLi in the presence of benzyl alcohol (BnOH) in diethyl ether or tetrahydrofuran produces
compounds [(EDBP-H)Li(BnOH)]2 (2) and [(EDBP-H)Li(BnOH)(THF)2] (3), respectively. Further reaction
of 2 with excess of THF produces 3. Alternatively, 3 can also be prepared by the reaction of benzyl alcohol
with 1 in toluene. Experimental results show that 2 and 3 efficiently initiate the ring-opening
polymerization (ROP) of l-lactide in a controlled fashion, yielding polymers with very narrow polydispersity
indexes in a wide range of monomer-to-initiator ratios. Block copolymers, polystyrene-b-poly(l-lactide),
have also been prepared from the ring-opening polymerization of l-latide catalyzed by 3 using polystyrene
as a macroinitiator.