TY - JOUR
T1 - "Liquid chromatography at critical conditions (LCCC): Capabilities and limitations for polymer analysis,
T2 - Capabilities and limitations for polymer analysis
AU - Molnar, Kristof
AU - Helfer, Carin A.
AU - Kaszas, Gabor
AU - Krisch, E.
AU - Chen, Dongjie
AU - McKenna, Gregory
AU - Kornfield, Julia A.
AU - Puskas, Judit E.
N1 - Funding Information:
The Authors would like to thank Dr. Prajakatta Mulay, Mauricio Azevedo de Freitas and Andres Munoz Salgado for their contribution to this work. This work was supported by the U.S. Department of Energy , Office of Science, Basic Energy Sciences under Award # DE-SC0018891 .
Publisher Copyright:
© 2020 Elsevier B.V.
PY - 2021/1/15
Y1 - 2021/1/15
N2 - This paper investigates liquid chromatography at critical condition (LCCC) for polymer analysis. Based on controversial claims on the separation of cyclic polymers from linear analogues in the literature, the efficiency of LCCC for separation and purity analysis is questioned. Polyisobutylene (PIB) and poly(3,6-dioxa-1,8-octanedithiols) (polyDODT) were used for the study. The structure of low molecular weight cyclic and linear polyDODT was demonstrated by MALDI-ToF. NMR did not show the presence of thiol end groups in higher molecular weight PIB-disulfide and polyDODT samples, so they were considered cyclic polymers. When a low molecular weight polyDODT oligomer with only traces of cycles, as demonstrated by MALDI-ToF, was mixed with an Mn = 27 K g/mol cyclic sample, LCCC did not detect the presence of linear oligomers at 6 wt%. Based on the data presented here, it can be concluded that the LCCC method is not capable of measuring <6 wt% linear contamination so earlier claims for cyclic polystyrene (PS) samples purified by LCCC having <3% linear contaminants are questioned.
AB - This paper investigates liquid chromatography at critical condition (LCCC) for polymer analysis. Based on controversial claims on the separation of cyclic polymers from linear analogues in the literature, the efficiency of LCCC for separation and purity analysis is questioned. Polyisobutylene (PIB) and poly(3,6-dioxa-1,8-octanedithiols) (polyDODT) were used for the study. The structure of low molecular weight cyclic and linear polyDODT was demonstrated by MALDI-ToF. NMR did not show the presence of thiol end groups in higher molecular weight PIB-disulfide and polyDODT samples, so they were considered cyclic polymers. When a low molecular weight polyDODT oligomer with only traces of cycles, as demonstrated by MALDI-ToF, was mixed with an Mn = 27 K g/mol cyclic sample, LCCC did not detect the presence of linear oligomers at 6 wt%. Based on the data presented here, it can be concluded that the LCCC method is not capable of measuring <6 wt% linear contamination so earlier claims for cyclic polystyrene (PS) samples purified by LCCC having <3% linear contaminants are questioned.
KW - Critical conditions
KW - Disulfide cyclic polymers
KW - Liquid chromatography
KW - Poly(3,6-dioxa-1,8-octanedithiol)
KW - Polyisobutylene
KW - Sensitivity
UR - http://www.scopus.com/inward/record.url?scp=85097708759&partnerID=8YFLogxK
U2 - 10.1016/j.molliq.2020.114956
DO - 10.1016/j.molliq.2020.114956
M3 - Article
SN - 0167-7322
VL - 322
SP - 114956
JO - Journal of Molecular Liquids
JF - Journal of Molecular Liquids
M1 - 114956
ER -