TY - JOUR
T1 - Insights into Azetidine Polymerization for the Preparation of Poly(propylenimine)-Based CO2 Adsorbents
AU - Sarazen, Michele L.
AU - Jones, Christopher W.
N1 - Funding Information:
Funding for this work was provided as part of UNCAGE-ME, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under Award DE-SC0012577 and by Global Thermostat, LLC.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/12/12
Y1 - 2017/12/12
N2 - The cationic ring-opening polymerization of azetidine to form branched poly(propylenimine) (PPI) is investigated for the purpose of evaluating the utility of PPI/silica composite adsorbents for CO2 capture. The polymerization kinetics and primary:secondary:tertiary amine distribution are monitored with 1H NMR during reaction with varied synthesis conditions (i.e., reaction time 20-150 h), temperature (343-353 K), and monomer to acid initiator (here, HClO4) ratio. It is found that primary amines are converted to tertiary amines with increased polymerization time, while the addition of monomer over the first 6 h of polymerization increases the primary amine content. This suggests a mechanism where the monomer is rapidly consumed, leaving dimers or small oligomers that still contain rings as key reaction centers. The synthesized polymer is neutralized with either NH4OH or a basic resin and impregnated into mesoporous silica (SBA-15). The CO2 capture properties of these composite adsorbents are investigated, giving information about the effectiveness of the acid neutralization processes.
AB - The cationic ring-opening polymerization of azetidine to form branched poly(propylenimine) (PPI) is investigated for the purpose of evaluating the utility of PPI/silica composite adsorbents for CO2 capture. The polymerization kinetics and primary:secondary:tertiary amine distribution are monitored with 1H NMR during reaction with varied synthesis conditions (i.e., reaction time 20-150 h), temperature (343-353 K), and monomer to acid initiator (here, HClO4) ratio. It is found that primary amines are converted to tertiary amines with increased polymerization time, while the addition of monomer over the first 6 h of polymerization increases the primary amine content. This suggests a mechanism where the monomer is rapidly consumed, leaving dimers or small oligomers that still contain rings as key reaction centers. The synthesized polymer is neutralized with either NH4OH or a basic resin and impregnated into mesoporous silica (SBA-15). The CO2 capture properties of these composite adsorbents are investigated, giving information about the effectiveness of the acid neutralization processes.
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U2 - 10.1021/acs.macromol.7b02402
DO - 10.1021/acs.macromol.7b02402
M3 - Article
AN - SCOPUS:85038207321
SN - 0024-9297
VL - 50
SP - 9135
EP - 9143
JO - Macromolecules
JF - Macromolecules
IS - 23
ER -