Selective synthesis of cyclic-polymer-free poly(ether sulfone)s with OH ends or F ends by non-stoichiometric, reversible polycondensation
Reversible polycondensation of bis(phenol) silyl ether 1 and bis(4-fluorophenyl) sulfone 2 with an excess of one monomer in the presence of base was investigated for the synthesis of telechelic poly(ether sulfone) (PES) end-capped with the excess monomer, without the formation of cyclic polymer. In...
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Published in | Polymer chemistry Vol. 15; no. 27; pp. 2747 - 2752 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge
Royal Society of Chemistry
09.07.2024
|
Subjects | |
Online Access | Get full text |
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Summary: | Reversible polycondensation of bis(phenol) silyl ether
1
and bis(4-fluorophenyl) sulfone
2
with an excess of one monomer in the presence of base was investigated for the synthesis of telechelic poly(ether sulfone) (PES) end-capped with the excess monomer, without the formation of cyclic polymer. In the polycondensation of an excess of bisphenol A bis(trimethylsilyl ether) (
1a
) and
2
in the presence of K
2
CO
3
in
N
-methyl-2-pyrrolidone (NMP) ([
2
]
0
= 1.0 M) at 145 °C, PES having a phenol moiety derived from
1a
at both ends (designated as HO/OH) was obtained. The molecular weight increased up to
M
n
= 8380 as the excess ratio of
1a
was decreased, but the product was contaminated with cyclic polymer; this issue was overcome by increasing the monomer concentration ([
2
]
0
= 4.0 M). On the other hand, in the polycondensation using an excess of
2
, CsF was an effective base to obtain PES with a fluorophenyl sulfone moiety at both ends (designated as F/F). The polycondensation using 1.05 equivalents of
2
in
N
,
N
-dimethylacetamide (DMAc) ([
1a
]
0
= 4.0 M) at 165 °C afforded high-molecular-weight PES with F/F ends (
M
n
= 11 200), free from cyclic polymer. Furthermore, other compounds
1
were polymerized with
2
under the optimized conditions established for the polycondensation of
1a
with
2
. The polycondensation of 1.1 equivalents of
1c
, having a bis(trifluoromethyl) group, with 1.0 equivalent of
2
afforded PES with HO/OH ends, whereas the polycondensation of 1.0 equivalent of
1b
, bearing a cyclohexylidene group, with 1.1 equivalents of
2
afforded PES with F/F ends. In the polycondensation of unsubstituted bisphenol silyl ether
1d
with
2
, gelation occurred when an excess of either
1d
or
2
was used.
Non-stoichiometric, reversible polycondensation of bisphenol disilyl ether and bis(4-fluorophenyl) sulfone is a convenient approach to synthesize telechelic PES end-capped with the excess monomer, without the formation of cyclic polymers. |
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Bibliography: | 1 https://doi.org/10.1039/d4py00348a H NMR spectra, GPC profiles, MALDI-TOF mass spectra, and DSC charts. See DOI Electronic supplementary information (ESI) available: Experimental procedures |
ISSN: | 1759-9954 1759-9962 |
DOI: | 10.1039/d4py00348a |