Loading…
A base-conjugate-acid pair for living/controlled ring-opening polymerization of trimethylene carbonate through hydrogen-bonding bifunctional synergistic catalysis
The ring-opening polymerization (ROP) of trimethylene carbonate (TMC) using a base-acid binary organocatalyst system of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) and Brønsted acid trifluoromethanesulfonic acid (TFA) with benzyl alcohol (BnOH) as the initiator has been investigated. The MTB...
Saved in:
Published in: | Polymer chemistry 2014-10, Vol.5 (2), p.651-659 |
---|---|
Main Authors: | , , , , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Summary: | The ring-opening polymerization (ROP) of trimethylene carbonate (TMC) using a base-acid binary organocatalyst system of 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) and Brønsted acid trifluoromethanesulfonic acid (TFA) with benzyl alcohol (BnOH) as the initiator has been investigated. The MTBD and its conjugate-acid pair H-bonding bifunctional synergistic activation mechanism was demonstrated by NMR measurements, and the living/controlled nature of MTBD/TFA catalyzed ROP of TMC was confirmed by the kinetic and chain extension experiments. The controlled ROP of TMC with the optimal molar ratio of MTBD/TFA = 2/1 proceeded to afford well-defined PTMC with narrow molecular weight distributions (
M
w
/
M
n
∼ 1.1). The molecular weights determined by
1
H NMR are in precise agreement with the theoretical values.
1
H NMR, SEC, and MALDI-ToF MS measurements confirmed the structure of the obtained homopolymer PTMC. In addition, a diblock copolymer consisting of poly(trimethylene carbonate) and poly(
l
-lactide) (PTMC-
b
-PLLA) was synthesized successfully by the MTBD/TFA binary catalyst system.
Base-conjugate-acid pair in H-bond donor/acceptor organocatalysis in living polymerization was firstly reported as a general workable protocol in the ROPs. |
---|---|
ISSN: | 1759-9954 1759-9962 |
DOI: | 10.1039/c4py00773e |