10.1021/acssuschemeng.7b04284.s001
Congkai Ma
Congkai
Ma
Fei Xu
Fei
Xu
Weiguo Cheng
Weiguo
Cheng
Xin Tan
Xin
Tan
Qian Su
Qian
Su
Suojiang Zhang
Suojiang
Zhang
Tailoring Molecular Weight of Bioderived Polycarbonates
via Bifunctional Ionic Liquids Catalysts under Metal-Free Conditions
American Chemical Society
2018
bioderived high-molecular-weight polycarbonates
PIC
anion
1- butyl -3-methylimidazolium
isosorbide
Metal-Free Conditions Synthesis
hydrogen bond formation
IL
Bmim
glass transition temperature
M n
catalyst
Tailoring Molecular Weight
hydrogen bond formation ability
CHOHCOO
diol
2018-01-05 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Tailoring_Molecular_Weight_of_Bioderived_Polycarbonates_via_Bifunctional_Ionic_Liquids_Catalysts_under_Metal-Free_Conditions/5815842
Synthesis
of bioderived high-molecular-weight polycarbonates over
metal-free catalysts is of great importance but also challenging.
In this work, a series of 1-butyl-3-methylimidazolium (Bmim) ionic
liquids (ILs) were prepared as catalysts for a melt polycondensation
reaction of isosorbide and diphenyl carbonate. By modifying the structures
of ILs’ anions, the number-average molecular weight (<i>M</i><sub>n</sub>) of poly(isosorbide carbonate) (PIC) was effectively
tailored. In the presence of a trace amount (0.05 mol % based on isosorbide)
of bifunctional [Bmim][CH<sub>3</sub>CHOHCOO], the synthesized PIC
possessed high <i>M</i><sub>n</sub> of 61,700 g/mol and
a glass transition temperature of 174 °C, both the highest so
far to the best of our knowledge. Besides, it was found that the anions
with stronger electronegativity and hydrogen bond formation ability
were more efficient for the formation of PIC with higher <i>M</i><sub>n</sub>. To modify the flexibility of PIC, poly(aliphatic diol-<i>co</i>-isosorbide carbonate)s with <i>M</i><sub>n</sub> ranging from 34,000 to 75,700 g/mol were also formulated by incorporating
with various aliphatic diols. Additionally, based on the experimental
results and nuclear magnetic resonance spectroscopy, a possible mechanism
of cooperative nucleophilic–electrophilic activation through
hydrogen bond formation and electrostatic interactions by the ILs
catalyst was proposed.