Reworkable Polyhydroxyurethane Films with Reversible Acetal Networks Obtained from Multifunctional Six-Membered Cyclic Carbonates

Article abstract of DOI:10.1021/jacs.7b11824

Multifunctional 6-membered cyclic carbonates (6-CCs) comprising acetal structures have been synthesized via phosgene-free routes and utilized for the fabrication of reworkable networked poly(acetal-hydroxyurethane) (PAHU) films. Dibenzoyl-protected di(tri

Full text of DOI:10.1021/jacs.7b11824

Subscriber access provided by UNIV OF NEW ENGLAND ARMIDALE
Communication
Re-workable Polyhydroxyurethane Films with Reversible Acetal Networks
Obtained from Multi-functional Six-membered Cyclic Carbonates
Hiroyuki Matsukizono, and Takeshi Endo
J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.7b11824 • Publication Date (Web): 09 Jan 2018
Downloaded from http://pubs.acs.org on January 9, 2018
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Journal of the American Chemical Society is published by the American Chemical
Society. 1155 Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 5
Journal of the American Chemical Society
1
2
3
4
5
6
7
8
9
Re-workable Polyhydroxyurethane Films with Reversible Acetal
Networks Obtained from Multi-functional Six-membered Cyclic
Carbonates
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
Hiroyuki Matsukizono,* and Takeshi Endo
Molecular Engineering Institute, Kindai University11ꢀ6 Kayanomori, Iizuka, Fukuoka, Japan
Eꢀmail: hmatsukizono@moleng.fuk.kindai.ac.jp
Supporting Information Placeholder
ABSTRACT: Multiꢀfunctional 6ꢀmembered cyclic carbonates
6ꢀCCs) comprising acetal structures have been synthesized via
Scheme 1. a) Synthesis of Tri-functional 6-CC (Tri-
DTMPC) via phosgene-free routes. b) Chemical structures
of tetra- and hexa-functional 6-CCs (Tetra-DTMPC and
Hexa-DTMPC).
(
phosgeneꢀfree routes and utilized for the fabrication of reꢀ
workable networked poly(acetalꢀhydroxyurethane) (PAHU) films.
Dibenzoylꢀprotected di(trimethylolpropane) (DTMP) reacts with
multiꢀfunctional aldehydes derived from nonꢀexpensive alcohols
to afford protected multiꢀfunctional DTMPs. After deprotection,
the multiꢀfunctional DTMPs can react with diphenyl carbonate to
efficiently form multiꢀfunctional 6ꢀCCs. The polyaddition of the
6ꢀCCs and diamines effectively proceeds in DMF to give netꢀ
worked PAHU films with good transparency and flexibility. Theꢀ
se films possess the reꢀworkability based on acidꢀcatalyzed reꢀ
versibility of acetal linkages. In particular, the film fabricated
using large amounts of hexaꢀfunctional 6ꢀCCs can reꢀform reproꢀ
ducibly with maintaining to some degree its mechanical properties.
Poly(hydroxyurethane)s (PHUs) have been attracting huge atꢀ
tentions as the promising alternatives of widelyꢀused polyureꢀ
thanes because PHUs can be synthesized by the ringꢀopening
polyaddition of diꢀfunctional cyclic carbonates and diamines
1ꢀ5
without using toxic isocyanates. PHUs reported are basically
synthesized from 5ꢀmembered cyclic carbonates (5ꢀCCs) because
5ꢀCCs can be derived from epoxides and CO under environmenꢀ
2
1
ꢀ4
tally benign conditions. Furthermore, various epoxides includꢀ
1
ꢀ4
ing multiꢀfunctional structures are commercially available. Usꢀ
ing these epoxides, multiꢀfunctional 5ꢀCCs have been designed
1
a,4
and used to build networked PHU materials. On the other hand,
PHUs from 6ꢀmembered cyclic carbonates (6ꢀCCs) are not reportꢀ
1a,6
5,8
ed much. Although 6ꢀCCs are highly reactive, they are basiꢀ
cally synthesized from the corresponding 1,3ꢀdiols using toxic
phosgene or its derivatives except a few cases.
1
a,5
Moreover,
commerciallyꢀobtainable 1,3ꢀdiols are structurally limited. In
particular, multiꢀfunctional 6ꢀCCs requires special designs and
7
multiꢀstep synthetic procedures. These problems hinder the pracꢀ
tical usage of 6ꢀCCs and their application to PHU–based materiꢀ
als.
i) DPC, 140°C, 2 d. ii) Benzaldehyde/TsOH/MeOH, 50°C,
We have previously reported that trimethylolpropane (TMP)
and di(trimethylolpropane) (DTMP) efficiently react with dipheꢀ
nyl carbonate (DPC) to afford the corresponding 6ꢀCCs in good
overnight. iii) DPC/MgCl /DMF, 100°C, overnight. iv)
2
BzCl/pyridine/CH Cl , 0°C to r.t., overnight. v) Neopentylglyꢀ
2
2
col/TsOH/MeOH, 50°C, overnight. vi) TsCl/pyridine, 0°C to r.t.,
d. vii) Vanillin/K CO /DMF, 100°C, 3 d. viii) TsOH/CH Cl , 40
8
yields. DPC can be synthesized without phosgene and its derivaꢀ
2
°
9
2
3
2
2
tives and thus, the synthesis of 6ꢀCCs using DPC is one of phosꢀ
C, 2 d. ix) NaOH/THF/MeOH. r.t., overnight.
geneꢀfree routes. The excellent formative ability of these alcohols
to 6ꢀCCs helps us to design the unique strategy in synthesizing
ACS Paragon Plus Environment

Journal of the American Chemical Society
Scheme 2. Synthesis of networked PAHUs by the ring-
Page 2 of 5
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
opening polyaddition of multi-functional 6-CCs and DAP.
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
multiꢀfunctional 6ꢀCCs. Based on this concept, we designed the
synthetic route to multiꢀfunctional DTMPꢀbased 6ꢀCCs via the
acetal linkages (Scheme 1). Using these 6ꢀCCs bearing acetal
structures
and
diamines,
networked
poly(acetalꢀ
hydroxyurethane)s (PAHUs) comprising acetal and hydroxyureꢀ
thane structures are obtainable (Scheme 2). Generally, acetal
bonds are reversible under acidic conditions with H O and/or
2
1
0
alcohols and, therefore, there are many efforts to develop acetalꢀ
based functional polymers such as chemical recyclable materials
11
1
0,12
and pHꢀresponsive drug/geneꢀdelivery carriers
. In our system,
Figure 1. MALDIꢀTOFꢀmass spectra of multiꢀfunctional 6ꢀCCs.
a) Tri-DTMPC. b) Tetra-DTMPC. c) Hexa-DTMPC.
the acetalꢀincorporated networks potentially show reversible
crosslinking/deꢀcrosslinking functions based on acetal linkages,
i.e., PAHU materials expect to show reꢀworkable properties. Here
we report the phosgeneꢀfree synthesis of multiꢀfunctional DTMPꢀ
based 6ꢀCCs from commerciallyꢀavailable polyols and the fabriꢀ
cation of reꢀworkable networked PAHU films.
Multiꢀfunctional 6ꢀCCs were synthesized according to the route
shown in Scheme 1a. Details are summarized in Figure S1ꢀ25 and
Table S1. Our strategy utilizes the acetal formations between 1,3ꢀ
diols of DTMP and multiꢀfunctional aldehydes to build multiꢀ
functional polyols. During this reaction, to avoid the generation of
undesired polyacetals, the protection of one 1,3ꢀdiol of DTMP is
required. Besides, relativelyꢀstable 6ꢀmembered cyclic acetals
formed from 1,3ꢀdiols and aromatic aldehydes are favorable to
construct reꢀworkable PAHU networks. From these needs, we
synthesized benzoyl (Bz) protectedꢀDTMP (DTMP-Bz ) and
2
multiꢀfunctional aldehydes (Tri-Van) derived from vanillin and
1
3
TMP . After that, three DTMP-Bz arms were introduced into
2
14
Tri-Van core and then a triꢀfunctional polyol (Tri-DTMP) was
obtained by deꢀprotection. The model reaction of monoꢀfunctional
Ph-DTMP and DPC with MgCl proceeded without the cleavage
2
of acetal structures and consequently, Ph-DTMPC was obtained
in high yields (Figures S3 and S4), which suggests that multiꢀ
functional 6ꢀCCs are also obtainable by the same procedure. Acꢀ
tually, the MALDIꢀTOFꢀmass spectrum of the product from the
Figure 2. a) Fabrication of networked PAHU films (PAHU-
Hexa-n) from Hexa-DTMPC, DTMPC and DAP. Mole fractions
of Hexa-DTMPC per total carbonate monomer (Hexa-DTMPC
reaction of Tri-DTMP shows one major peak at m/z of 1,334
+
(
(
Figure 1a). This value equals to Mw of Tri-DTMPC with Na
1,312 + 23), indicating that Tri-DTMPC is successfully syntheꢀ
+
DTMPC) were 5 (n = 5), 10 (n = 10), 15 (n = 15), or 20 mol%
(n = 20). b) Representative SꢀS curves of PAHU-Hexa-15,
sized. Similarly, Tetra-DTMP and Hexa-DTMP were syntheꢀ
sized from DTMP and dipentaerythritol (DPE), respectively and
then reacted with DPC. These products also show the peaks which
PAHU-Tetra-15 and PAHU-Tri-15. c) Effect of monomer feed
ratios on averaged tensile strength (bars, left axis) or averaged
elongation (plots, right axis) at fracture points of networked
PAHU films. Top: PAHU-Hexa-n. Middle: PAHU-Tetra-n.
Bottom: PAHU-Tri-n. Error bars denote standard deviations.
equals to M of the corresponding target structures (Figure 1b, c).
w
Apart from these major peaks, minor peaks are confirmed, which
are mainly assigned to multiꢀfunctional 6ꢀCCs having less number
of DTMPC arms and those bearing acyclic carbonate structures
(Figure S22). Although these products contain the byꢀproducts,
the amounts of acetal structures and bis(phenoxycarbonyl) groups
originating from these impurities are extremely lower than those
of target structures (Table S1). Hence, we can conclude that the
multiꢀfunctional 6ꢀCCs can be efficiently synthesized by our apꢀ
proach.
Hexa-DTMPC, [6ꢀCC] /[NH ] = 1/1) were heated at 60°C overꢀ
0
2 0
night. During this treatment, the polyaddition effectively proceedꢀ
ed to form networked PAHU films (PAHU-Hexa-n, n denotes the
feed ratio of multiꢀfunctional 6ꢀCCs used). Hydroxyurethane
structures in these films are confirmed by the appearance of
stretching vibrations ascribed to OH groups and by the slight shift
of stretching vibrations originating from carbonyl groups (Figure
4
S26). Similarly, PAHU-Tetra-n and PAHU-Tri-n were successꢀ
Next, we reacted these 6ꢀCCs with 1,3ꢀdiaminopropane (DAP)
to fabricate networked PAHU films. As shown in Figure 2a, DMF
solutions of Hexa-DTMPC and DTMPC were mixed with the
DMF solution of DAP and then the mixtures (5ꢀ20 mol%
fully obtained from Tetra-DTMPC and Tri-DTMPC, respectiveꢀ
ly. All the resulting films are transparent and flexible (Figure S27)
at 0.084ꢀ0.168 mm thickness and exhibit the similar FTꢀIR spectra
ACS Paragon Plus Environment

Page 3 of 5
Journal of the American Chemical Society
(Figure S28). Although the remaining monomer terminals cannot
1
2
3
4
5
6
7
8
9
be detected in their FTꢀIR spectra, unreacted 6ꢀCC structures and
amino groups in PAHU-Hexa-20 are calculated to be ca. 22
mol%, which are described later. Furthermore, these films swelled
well in MeOH and DMF. In particular, PAHU-Tri-5 showed
higher swelling properties (Figure S29). The weight of these films
decreased by ca. 15% after the immersion in these solvents and
oligomeric PHUs mainly composed of DTMP and DAP were
collected from the supernatant.
Representative stressꢀstrain (SꢀS) curves of these PAHU films
are shown in Figure 2b. The tensile strength of PAHU-Hexa-15
linearly increased at < ca. 1.5% elongation and then nonlinearly
increased and the film was finally broken at ca. 140% elongation.
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
Its averaged tensile strength at the fracture point (σ ) was 26.4
f
MPa and higher than that of other two films. On the other hand,
an averaged tensile strength at the fracture point (ε ) of PAHU-
f
Hexa-15 was the lowest and PAHU-Tri-15 showed the highest εf.
These results suggest that more rigid but fragile films tend to form
with increasing the number of DTMPC arms of multiꢀfunctional
6ꢀCCs. This tendency is adequately rational because multiꢀ
functional 6ꢀCCs bearing greater numbers of monomer units tend
to afford polymer networks at higher densities. SꢀS curves of the
Figure 3. a) Schematic illustration of crosslinking/deꢀcrosslinking
functions of PAHU-Hexa-n under acidic conditions. b) Photoꢀ
graphs of PAHU-Hexa-20. The film was dissolved in DMF conꢀ
taining TsOH monohydrate by heating to afford a pale yellow
solution. After solvents were removed, a transparent and flexible
film formed again. c) Changes in σ and ε obtained from SꢀS
other films were measured (Figure S30ꢀ32) and their σ and ε are
f
f
f
f
summarized in Figure 2c. For all films, σ increased when the
curves of reꢀformed PAHU-Hexa-20. Cycle represents the repetiꢀ
f
molar fraction of multiꢀfunctional 6ꢀCCs increased from 5 to 15
tion number of reꢀformation processes.
mol%. On the other hand, ε tended to decrease in this range.
f
to form reꢀworkable films. By the solubilization of these films, we
can obtain detailed information about their networked structures.
As mentioned above, the remaining amino groups in PAHU-
Hexa-20 are determined to be approximate 20% (Table S2). Since
these amino groups trap acids, the cleavage of networked strucꢀ
tures needed slightly larger amounts of TsOH at the following deꢀ
crosslinking treatment (0.4 equiv. per acetal structure). The reꢀ
workable treatment was carried out 10 times and each reꢀformed
film was analyzed for its mechanical properties by tensile tests
However, σ decreased or remained unchanged with an increase in
f
the molar fraction of multiꢀfunctional 6ꢀCCs to 20 mol%. This
would be due to that excessive amounts of multiꢀfunctional 6ꢀCCs
sterically hinder the proceeding of the polyaddition and the forꢀ
mation of polymer networks.
Finally, we describe the reꢀworkable properties of these films.
As these films involve reversible acetal bonds, it is expected that
these films can be dissolved in solvents containing acids and H O
2
and then can be reꢀformed by the elimination of H O (Figure 3a).
2
(
Figure S41). The σ and ε of each reꢀformed film are plotted in
f f
As a preliminary study, we synthesized a linear PAHU (LPAHU)
and investigated its reversible fragmentation/extension behavior
(Scheme S1 and Figure S33ꢀ39). After LPAHU was heated in
Figure 3c. After the 1st reꢀformation process, its σ decreased,
f
while its ε marginally decreased. This change suggests that the
f
film became more flexible by the decrease in the amount of crossꢀ
DMF containing TsOH monohydrate at 60°C, its M decreased
n
ꢀ
1
1
linking points. After that, its σ and ε varied at the range at 6.0ꢀ
f f
dramatically from 9,300 to 1,600 g mol (Figure S38). In its H
NMR spectrum, the signal of acetal proton at 5.3 ppm apparently
decreased to ca. 60%, while the signal of aldehyde proton newly
appeared at 9.8 ppm (Figure S39). These result obviously indicate
the fragmentation of LPAHU chains via the formation of aldeꢀ
21.5 MPa and 74ꢀ143%, respectively. There are no relationship
and tendency between its mechanical properties and the repetition
number of the reꢀformation process. Because acetalꢀbased netꢀ
works are strongly affected by coexisting H O, we consider that
2
the changes in its mechanical properties would be caused by the
hydes. After all solvents (H O and DMF) were removed at 60 °C
2
humidity. The averaged σ and ε of the film during 1stꢀ10th reꢀ
f
f
under reduced pressure, the signal of acetal proton adequately
recovered and its SEC trace gave a peak based on higher molecuꢀ
formation processes are 13.0 MPa and 112%, respectively. Comꢀ
pared to the nonꢀreꢀformed film, the decreases in its σ and ε are
f
f
lar mass structures with a relativelyꢀnarrow polydispersity (M =
n
ꢀ1
only 3 and 33%, respectively. Therefore, we conclude that the
film maintains to some extent mechanical properties after the
repetitive reꢀformation process and has a potential to be applied to
a reꢀworkable film.
4
,600 g mol , M /M = 2.86). These results indicate that the
w
n
fragmented LPAHU chains are partially extended by acetal forꢀ
mations between their aldehyde and 1,3ꢀdiol chain ends.
Similar to LPAHU, networked PAHU films were examined for
their crosslinking/deꢀcrosslinking properties. These films were
dissolved to afford pale yellow solutions (Figure 3b) by heating in
DMF containing TsOH monohydrate (0.2ꢀ0.4 equiv. per acetal
structure). Because these films were insoluble in DMF without
acids, this solubilization clearly indicates the partial cleavage of
In this paper, we designed multiꢀfunctional DTMPꢀbased 6ꢀ
CCs bearing acetal structures from nonꢀexpensive materials and
used them for the fabrication of reꢀworkable networked PAHU
films. Our strategy utilizing acetal linkages makes it possible to
extend the variation of the design of 6ꢀCCs via phosgeneꢀfree
conditions. In addition, the resulting acetal linkages are stable in
basic condition and therefore, PHUs can be obtained without the
cleavage of acetal bonds. Furthermore, these acetal linkages can
serve as reversible crosslinking points under acidic conditions,
which affords reꢀworkable properties. Although remendable PHU
1
PAHU networks. The H NMR spectrum of dissolved PAHU-
Hexa-20 reveals that ca. 60% acetal bonds converted to aldehydes
(Figure S40). After the elimination of the solvents, PAHU-Hexa-
20 was again obtained as a transparent and flexible film (Figure
3b). This result suggests the crosslinking of partiallyꢀcleaved netꢀ
4
d
materials utilizing DielsꢀAlder reactions have been reported , our
films need catalytic amounts of acids, water and thermal energy,
i.e., our system does not work by a simple addition of thermal
energy and is applicable under higher temperature conditions. To
works caused by the elimination of H O. Unfortunately, selfꢀ
2
standing films were not reproducibly obtained for other films,
which implies that larger amounts of acetal linkages would need
ACS Paragon Plus Environment

Journal of the American Chemical Society
Page 4 of 5
our best knowledge, our study is the first report discussing netꢀ
worked PHU materials comprising acetal linkages and their reꢀ
workable feature based on their acetal linkages. Our approach will
be one of the fundamental for designing multiꢀfunctional 6ꢀCCs
under phosgeneꢀfree conditions and for fabricating reꢀworkable
networked PHU materials.
Phys. Chem. 2012, 116, 10607. c) Nishihara, R. Catal. Surv. Asia
010, 14, 140.
10) a) Liu, B.; Thayumanavan, S. J. Am. Chem. Soc. 2017, 139, 2306.
b) Gillies, E. R.; Goodwin, A. P.; Frechét, J. M. J. Bioconjugate
Chem. 2004, 15, 1254.
11) Yamaguchi, A.; Hashimoto, T.; Kakichi, Y.; Urushisaki, M.;
Sakaguchi, T.; Kawabe, K.; Kondo, K.; Iyo, H. J. Polym. Sci.
PartA: Polym. Chem. 2015, 53, 1052.
(12) a) Louage, B.; Steenbergen, M. J.; Nuhn, L.; Risseeuw, M. D. P.;
Karalic, I.; Winne, J.; Calenbergh, S. V.; Hennink, W. E.; Geest,
B. G. D. ACS Macro Lett. 2017, 6, 272. b) Huang, D.; Yang, F.;
Wang, X.; Shen, H.; You, Y.; Wu, D. Polym. Chem. 2016, 7,
2
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
(
(
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the
6
154.
(13) a) Laliberté, D.; Maris, T.; Sirois, A.; Wuest, J. D. Org. Lett.
003, 5, 4787. b) Deng, G.; Tang, C.; Li, F.; Jiang, H.; Chen, Y.
ACS
Publications
website:.
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
Experimental details including spectroscopic data, characterizaꢀ
tion of polymers and networked films: photographs, spectroscopic
measurements, swelling properties and tensile tests (PDF)
2
Macromolecules 2010, 43, 1191.
(
14) a) Pemba, A. G.; Rostagno, M.; Lee, T. A.; Miller, S. A. Polym.
Chem. 2014, 5, 3214. b) Llevot, A.; Grau, E.; Carlotti, S.; Grelier,
S.; Cramail, H. Macromol. Rapid Commun. 2016, 37, 9.
AUTHOR INFORMATION
Corresponding Author
hmatsukizono@moleng.fuk.kindai.ac.jp.
Notes
The authors declare no competing financial interests.
ACKNOWLEDGMENT
This work was financially supported by JSR Co., Ltd.
REFERENCES
(
1) a) Cornille, A.; Auvergne, R.; Figovsky, O.; Boutevin, B.; Caillol,
S. Eur. Polym. J. 2017, 87, 535. b) Maisonneuve, L.; Lamarzelle,
O.; Rix, E.; Grau, E.; Cramail, H. Chem. Rev. 2015, 115, 12407.
c) Nohra, B.; Candy, L.; Blanco, J.ꢀF.; Guerin, C.; Raoul, Y.;
Mouloungui, Z. Macromolecules 2013, 46, 3771. d) Kathalewar,
M. S.; Joshi, P. B.; Sabnis, A. S.; Malshe, V. C. RSC Adv. 2013,
3, 4110.
(
2) a) Beniah, G.; Chen, X.; Uno, B. E.; Liu, K.; Leitsch E. K.; Jeon,
J.; Heath, W. H.; Scheidt, K. A.; Torkelson, J. M. Macromole-
cules 2017, 50, 3193. b) Ochiai, B.; Kojima, H.; Endo, T. J.
Polym. Chem. PartA: Polym. Chem. 2014, 52, 1113.
(
3) a) Schmidt, S.; Gatti, F. J.; Luitz, M.; Ritter, B. S.; Bruchmann,
B.; Mülhaupt, R. Macromolecules 2017, 50, 2296. b) Lamarzelle,
O.; Durand, P.ꢀL.; Wirotius, A.ꢀL.; Chollet, G.; Grau, E.; Cramail,
H. Polym. Chem. 2016, 7, 1439. c) MazurekꢀBudzyńska, M. M.;
Rokicki, G.; Drzewicz, M.; Guńka, P. A.; Zachara, J. Eur. Polym.
J. 2016, 84, 799. d) Annunziata, L.; Diallo, A. K.; Fouquary, S.;
Michaud, G.; Simon, F.; Brusson, J.ꢀM.; Carpentier, J.ꢀF.; Guilꢀ
laume, S. M. Green Chem. 2014, 16, 1947.
(4) a) Schimpf, V.; Heck, B.; Reiter, G.; Mülhaupt, R. Macromole-
cules 2017, 50, 3598. b) Blattmann, H.; Mülhaupt, R. Macromol-
ecules 2016, 49, 742. c) Grignard, B.; Thomassin, J.ꢀM.; Gennen,
S.; Poussard, L.; Raquez, J.ꢀM.; Dubois, P.; Tran, M.ꢀP.; Park, C.
B.; Jerome, C.; Detrembleur, C. Green Chem. 2016, 18, 2206. d)
Dolci, E.; Michaud, G.; Simon, F.; Boutevin, B.; Fouquary, S.;
Caillol, S. Polym. Chem. 2015, 6, 7851.
(
5) a) Pyo, S.ꢀH.; Wang, P.; Hwang, H. H.; Zhu, W.; Warner, J.;
Chen, S. ACS Appl. Mater. Interfaces 2017, 9, 836. b) Gregory,
G. L.; Jenisch, L. M.; Charles, B.; KociokꢀKöhn, G.; Buchard, A.
Macromolecules, 2016, 49, 7165. c) Maisonneuve, L.; Wirotius,
A.ꢀL.; Alfos, C.; Grau, E.; Cramail, H. Polym. Chem. 2014, 5,
6
142.
(6) a) Tomita, H.; Sanda, F.; Endo, T. J. Polym. Sci. PartA: Polym.
Chem. 2001, 39, 162. b) Tomita, H.; Sanda, F.; Endo, T. J.
Polym. Sci. PartA: Polym. Chem. 2001, 39, 860.
(7) Goodwin, A. P.; Lam, S. S.; Fréchet, J. M. J. J. Am. Chem. Soc.
2007, 129, 6994.
(8) a) Matsukizono, H.; Endo, T. Macromol. Chem. Phys. 2017, 218,
1
9
700043. b) Matsukizono, H.; Endo, T. Polym. Chem. 2016, 7,
58. c) Matsukizono, H.; Endo, T. RSC Adv. 2015, 5, 71360. d)
Matsukizono, H.; Endo, T. J. Appl. Polym. Sci. 2015, 132, 41956.
9) a) Kanega, R.; Hayashi, T.; Yamanaka, I. ACS Catal. 2013, 3,
(
3
89. b) Murayama, T.; Hayashi, T.; Kanega, R.; Yamanaka, I. J.
ACS Paragon Plus Environment

Page 5 of 5
Journal of the American Chemical Society
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
5
5
6
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
5
ACS Paragon Plus Environment