Access to Hydroxy-Functionalized Polypropylene through Coordination Polymerization

Article abstract of DOI:10.1002/anie.201914747

Preparation of polyethylenes containing hydroxy groups has been already industrialized through radical copolymerization under harsh conditions followed by alcoholysis. By contrast, hydroxy-functionalized polypropylene has proven a rather challenging goal

Full text of DOI:10.1002/anie.201914747

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Accepted Article
Title: A Strategy and the Mechanism to Access Hydroxy Functionalized
Polypropylene via Coordination Polymerization
Authors: Yuanhao Zhong, Tiantian Wang, Chunji Wu, Laurent Maron,
and Dongmei Cui
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To be cited as: Angew. Chem. Int. Ed. 10.1002/anie.201914747
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10.1002/anie.201914747
Angewandte Chemie International Edition
COMMUNICATION
A Strategy and the Mechanism to Access Hydroxy Functionalized
Polypropylene via Coordination Polymerization
Yuanhao Zhong,[a,b] Iskander Douair,[c] Tiantian Wang,[a,d] Chunji Wu,*,[a] Laurent Maron*,[c] and
Dongmei Cui*,[a]
Abstract: Preparation of polyethylene containing hydroxyl
groups has been already industrialized through radical
copolymerization under harsh conditions followed by alcoholysis.
On contrary, the hydroxyl functionalized polypropylene has been
a rather challenging project of polymer science. Propylene can’t
be polymerized via radical mechanism, and its coordination
copolymerization with polar monomers is frustrated by the
catalyst poison. Herein we report a new strategy to reach this
target. The coordination polymerization of allenes by rare-earth
metal precursors affords pure 1,2-regulated polyallenes, which
are facilely transferred to poly(ally alcohol) analogues followed
by hydroboration-oxidation. Strikingly, the copolymerization of
allenes and propylene gives the unprecedented hydroxyl
Lewis acid;[5] and the anionic and coordination catalysts react
with the hydroxyl group prior to the C=C bond. The more efficient
manner of getting a linear PAA with high molecular weight (30
kDa) and a block copolymer with styrene P(AA-St) is reported
recently by Hillmyer via the reversible addition-fragmentation
chain transfer (RAFT) radical polymerization of the Boc-
protected (bis(tert-butyloxy carbonate)) vinyl ester or vinyl amide
followed
by
post-polymerization
reduction.[6]
The
copolymerization of propene with allyl acetate, which is another
way to reach PP that includes hydroxyl functionalities after
hydrolysis. While the insertion rate of allyl acetate was poor. [7]
Therefore, coordination polymerization of the only adopted
manner for fabricating PP hasn’t been applied to prepare PAA or
hydroxy containing PP, since even the Boc-protected polar
monomers are poisonous to the employed coordination catalysts.
Allene compounds are widely employed as building blocks in
the field of organic synthesis due to the highly active cumulative
double bonds.[8] They also attract attention of polymer scientists,
since the corresponding polymers possess double bonds that
can be transferred into other functionalities via hydrogenation[9],
epoxidation[10] and hydrosilylation[11] etc post-polymerization
modification. However, the high activity of the cumulative double
bonds arouses difficulty to control polymer microstructures
through either radical or cationic polymerization.[12] The well
controlled polymerization of allenes is achieved by using
functionalized
polypropylene
after
post-polymerization
modification. The mechanism elucidated by DFT simulation
suggests the kinetically favored rather than thermo dynamical
control.
Synthesis of hydroxyl functionalized (co)polymers in particular
polyolefins has been the pursuing target of polymer scientists,
because hydroxyl group endows the materials with hydrophilicity
and excellent surface properties, besides, it is a reactive group
to be facilely transferred into other functionality. For instance,
polyethylene (PE) is the most famous and widely applied
hydrophobic plastics,[1] whilst its hydroxyl functionalized
derivatives such as poly(vinyl alcohol) (PVA) and poly(ethylene-
vinyl alcohol) (EVOH) possess rather unique properties and
apply in different fields.[2] To date the copolymerization of
ethylene with a broad scope of functional vinyl monomers has
been thoroughly investigated and achieved great successes,[3]
coordination catalysts. Of which the Ti[10] based systems, η3-allyl
[13]
NiOCOCF3
and the rare-earth metal[14] catalysts display
almost pure 2,3-selectivity. Nevertheless, the resultant polymers
contain the internal C=C double bonds that are chemically stable
and reluctant to be further transferred. In contrast, the 1,2-
selective polymerization of allenes gives polymers with the
active terminal C=C double bonds, however, which is sterically
disfavored.
except
hydroxyl
functionalization.
Fortunately,
radical
polymerization of vinyl acetate or copolymerization with ethylene
under high temperature and pressure followed by post-
polymerization alcoholysis affords PVA and EVOH, which is a
rather efficient and industrialized method.[4] On contrary, the
synthesis of the corresponding hydroxyl functionalized
polypropylene (PP) from the direct polymerization of allylic
alcohol (AA) or its copolymerization with propylene encounters
serious problems. Although allyl alcohol (AA) is a stable
chemical, it is hard to propagate into a high molecular weight
PAA via radical polymerization even under the assistance of a
Herein, we report the highly active and distinguished 1,2-
selective coordination polymerization of allene monomers (Chart
1) and its copolymerization with propylene by using the rare-
earth metal precursors (Chart 2). The resultant poly(allene)s
have high molecular weights, which are facilely transferred into
analogous PAAs through hydroboration-oxidation reactions
under mild conditions. Strikingly, the copolymerization of
propylene and allene monomers is also successul to afford the
unprecedented hydroxy functionalized PP after post-
polymerization modification. The mechanism for the activity and
1,2-selectivity is elucidated through DFT simulation, indicating a
[a]
Mr. Y. Zhong, Dr. C. Wu, Miss T. Wang, Prof. D. Cui
State Key Laboratory of Polymer Physics and Chemistry,
Changchun Institute of Applied Chemistry, Chinese Academy of
Sciences, Changchun 130022, China.
E-mail: dmcui@ciac.ac.cn
[b]
[c]
Mr. Y. Zhong
University of Chinese Academy of Sciences, Beijing, 100049, P. R.
China
Mr. I. Douair and Prof. Dr. L. Maron
LPCNO, CNRS & INSA, UPS, Université de Toulouse
135 Avenue de Rangueil, 31077 Toulouse (France)
E-mail: Laurent.maron@irsamc.ups-tlse.fr
Miss T. Wang
University of Science and Technology of China. Hefei 230026, China.
Supporting information for this article is given via a link at the end
ofthe document.
[d]
Chart 1. Allene Monomers.
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10.1002/anie.201914747
Angewandte Chemie International Edition
COMMUNICATION
range of  2.0 to 0.5 are attributed to the alkyl C10H21 protons.
The peak at  5.63 assigned to the internal methylene protons
Hc is rather weak. The ratio of the integral intensities of Ha : Hc
indicates a 94% 1,2-tacticity, higher than those obtained from
any other catalysts reported to date. Intrigued by these results,
we investigated in details the catalytic performance of complex 3
under various conditions. The representative data were collected
in Table 2. Changing the n-decylallene-to-Sc ratio from 100:1 to
500:1, the molecular weight of the resultant poly(n-decylallene)
increased correspondingly from Mn = 1.8×104 to 3.6×104 while
the molecular weight distribution maintained constantly (Table1,
entry 5; Table 2, entries 1 and 2). This indicated that the
polymerization was controllable and the active species was
single-sited, avoiding any side reactions and crosslinking
products. Noted that addition of AliBu3 (Al: Sc = 10:1) to the
above binary system [Sc]/[Ph3C][B(C6F5)4] did not show any
obvious influence on the catalytic performances (Table 2, entry
3). Lowering the polymerization temperature to 0oC, a higher
molecular weight polymer with a distinguished 1,2-regularity (Mn
Chart 2. Rare-earth Metal Precursors 1-3.
kinetically favored rather than the thermo dynamical control
procedure.
The PNP-carbazolide scandium (1a) and yttrium (1b)
bis(alkyl) complexes, upon activation of [Ph3C][B(C6F5)4] show
distinguished activity and perfect cis-1,4-selectivity for the
polymerization of conjugated diene monomers.[15] Both were
firstly tempted to catalyze n-decylallene polymerization (Table 1,
entries 1 and 2) but completely inert. Then, the constrained
geometry-configuration catalysts (CGC), the methylene pyridine
side-armed fluorenyl rare-earth metal bis(alkyl) complexes (Flu-
CH2-Py)Ln(CH2SiMe3)2(THF)n (Ln= Sc, n =0, 2a; Y, n = 1, 2b) in
combination with [Ph3C][B(C6F5)4] and AliBu3 were employed.
The polymerization of n-decylallene with the yttrium precursor
2b afforded only trace amount of polymer, contrary to its
behavior towards phenylallene polymerization reported
previously to exhibit high activity and pure 2,3-selectivity.[14]
Switching to the more Lewis acidic scandium precursor 2a, the
polymerization was performed efficiently to reach 90%
conversion in 24 h. The isolated polymer showed an improved
1,2-regularity (72%) (Table 1, entries 3 and 4). Therefore, we
turned to the less bulky half-sandwich thiophene-fused-
cyclopentadienyl scandium complex 3 that is highly active for
ethylene polymerization.[16] The polymerization went smoothly to
reach 92.2% conversion under the same conditions to those
using precursors 3 and gave a poly(n-decylallene) with a
moderate molecular weight (Mn = 1.8×104) (Table 1, entry 5).
=
3.7×104, 96%) was afforded. Further decreased the
temperature to -20oC and -40oC, respectively, the polymerization
could still perform fluently to achieve an over 85% conversion
albeit at a prolonged polymerization time. Meanwhile, the 1,2-
selectivity increased strikingly over 99% (Figure 1, middle). In
the 13C NMR spectrum the terminal vinyl carbon Ca shows a
resonance at  109 and the ternary carbon Cb displays a sharp
singlet at  152, whilst the methine carbon Cc appears at  51.
There are no resonances from the other regularities, indicating
an almost pure 1,2-regularity (Figure 2), which is further
confirmed by the HSQC spectrum analysis (Figure S39).
Compared to the 2,3-selectivity for allene polymerization the 1,2-
selectivity means a spacially disfavored route, therefore, the
such recorded high value of 1,2-selectivity, as far as we are
aware, is indeed unconventional. The physical property of
poly(n-decylallene) products is strongly dependent on the
microstructure. The polymer having
a
94% 1,2-tacticity
1
o
The H NMR spectrum of the resultant polymer (Figure 1, top)
possesses a Tg value of -27 C without melting point (Tm), while
that bearing an over 99% 1,2-tacticity gives a melting point Tm=
39 oC owing to its more regulated microstructure albeit
containing long soft alkyl side chains (Figure 3).
shows two groups of broad peaks at  5.21 and 2.8 assigned to
the terminal vinyl protons Ha and methine proton Hb on the 1,2-
regulated polymer chains, while the broad resonances within the
Table 1. Polymerization of n-decylallene catalyzed by complexes 1-3. [a]
Entry Cat Conv.(%) 1,2% [b] Mn[c]×10-4 PDI[c] Tg/ Tm[d] (oC)
1
1a
1b
2a
2b
3
trace
0
-
-
-
-
-
-
-/-
-/-
2
3[e]
4[e]
5[f]
90
72
-
1.3
-
1.39
-
-27/-
-/-
trace
92.2
94
1.8
1.47
-27/-
[a] Conditions: Cat 10 μmol, Mon/Cat =100, [Ph3C][B(C6F5)4] 10 μmol,
Toluene 0.2mL, T=20 oC, Time 24h. [b] Measured by 1H NMR in C6D4Cl2 at
Figure 1. 1H NMR spectrum of poly(n-decylallene) obtained at 20 oC (top,
Table 1, entry 5), -40 oC (middle, Table 2, entry 6) and hydroxylated
polymer (bottom) (400MHz, C6D4Cl2, 100 oC).
100 oC. [c] Determined by GPC in C6H3Cl3 at 150 ℃ against polystyrene
standard. [d] Determined by DSC. [e] AliBu3 10 μmol. [f] AliBu3 20 μmol.
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10.1002/anie.201914747
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COMMUNICATION
active species and then isomerizes to 1-phenoxy-1,3-butadiene
through 1,3-hydrogen shift.[17] Strikingly, monomer G containing
a butyl spacer polymerized rather fluently to generate pure 1,2-
tacticity (Table 2, entries 12-16).
Then the mechanism of highly active and chemoselective
(1,2 vs. 2,3) performance for the polymerization of allenes A, B,
C or G was then elucidated at the DFT level (B3PW91) based
on catalysts 2a and 3. In the following, only insertion of
monomer B was considered as representative of the allene
polymerization. Experimentally, complex 2a appears to be less
1,2 selective than catalyst 3. The two first insertions (1,2 and
2,3) were computed for catalyst 2a (see Figure S64). It is found
that there is a clear kinetic competition between the two
insertions in line with the moderate selectivity of this complex for
the 1,2 insertion. Indeed, the first insertion seems to be 1,2
(barrier of 10.0 vs. 13.6 kcal/mol) whereas the second one might
be a 2,3 (11.9 kcal/mol vs. 6.9 kcal/mol). On the other hand, the
reactivity of complex 3 seems very different (Scheme 1).
Interestingly, the 1,2 insertion appears to be kinetically always
more favorable than the 2,3 one (barrier of 7.0 vs. 10.4 kcal/mol
for the first insertion and of 0.5 vs. 8.0 kcal/mol for the second
one). This is in line with the greater selectivity for the 1,2-
insertion observed experimentally. This selectivity appears to be
due to the fact that no stable 1,2 adduct can be formed whereas
stable 2,3 can. The stability of the later is therefore reducing the
2,3 reactivity. However, it should be noticed that 1,2 selectivity
appears to be kinetically driven as the 2,3-insertion product, that
appears to be a π-allyl, is thermodynamically favored. Therefore,
at high temperature, formation of the thermodynamic product
should be observed, reducing the 1,2 selectivity, whereas the
1,2 selectivity should be greater at low temperature (low energy
demand for the reaction). This is in perfect agreement with the
experimental results (Table 2, entries 8 and 9). Therefore, the
reaction sequence is controlled by the kinetically facile 1,2
insertion but not by the coordination of the monomer to the metal
center. This finding is quite unusual for classical coordination-
insertion mechanisms and is associated to the steric repulsion
between the growing polymer chain and the allene, which
prevents the formation of a 1,2 adduct.
Figure 2. 13C NMR spectrum of poly(n-decylallene) obtained at -40
oC (Table 2, entry 6) (125 MHz, CDCl3, 25 oC).
Tg=-27℃
a
b
c
Tm=39℃
d
-40 -30 -20 -10
0
10 20 30 40 50 60 70 80 90 100
Temperature /℃
Figure 3. DSC traces of poly(n-decylallene)s with different 1,2-
tacticities. a: 1,2% = 94% (Table 1, entry 5); b: 1,2% = 96% (Table 2,
entry 4); c: 1,2% = 98% (Table 2, entry 5); d: 1,2% > 99% (Table 2, entry
6).
The distinguished performances of complex 3 towards n-
decylallene drove us to explore the polymerizations of allene
derivatives bearing different substituents. Monomer B containing
n-hexyl group was polymerized to give poly(n-hexylallene) with
the identical 1,2-regularity as poly(n-decylallene), suggesting
that the length of the side alkyl chain has no obvious influence
on the selectivity (Table 2, entries 8 and 9). The polymerization
of monomer C possessing a terminal C=C double bond exhibited
the regio-selectivity at the allene unit exclusively, indicating the
high reactivity of the cumulative double bonds than the discrete
double bond (Table 2, entries 10 and 11). To investigate the
influence of polar substituents, monomers D, E, F and G were
synthesized. Monomer D has a propyloxo fragment attached to
the cumulative double-bonds. During the polymerization the
oxygen atom is geometrically available to back-bite the active
Sc3+ ion together with the cumulative unit, generating a strong
chelate to retard the polymerization (Scheme S1). Replacing the
n-C6H13 species in D by a phenyl group is anticipated to avoid
oxygen from poisoning the active species, thus, monomer F
indeed could be polymerized sluggishly to reach 42%
conversion in 72h albeit with a rather low 1,2-selectivity (13.0%).
This might be attributed to the weak back-biting chelation of the
phenoxyl to the active metal center to arouse a crowding and
variable coordination-insertion environment. Monomer E bearing
the methylene unit between the cumulative double bonds and
phenoxyl group was completely inert, which coordinates to the
The hydrolysis of the obtained polymers was performed via
hydroboration with BH3 followed by oxidation with H2O2 under
mild conditions. In the 1H NMR spectrum the peak at  5.21
assigned to the terminal vinyl protons is almost invisible, while
the broad resonance at  3.75 is attributed to the methylene CH2
group adjacent to the hydroxyl group, suggesting the rather high
efficiency of this post-polymerization modification (Figure 1,
bottom). In the FTIR (cm−1) trace, the characteristic C=C
stretching vibration at 1648 arising from 1,2-regulated
poly(alkylallene) is nearly absent while a strong and broad
resonance at 3300 cm−1 is attributed to the stretching vibration of
the newly generated O-H bond (Figure S61).
The surface property of the nonpolar poly(alkylallene) is
greatly improved after hydrolysis to decyl substituted PAA by
giving a smaller static water contact angle (WCA) of 96.2° as
compared to 107.7° for poly(alkylallene).[18]
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10.1002/anie.201914747
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COMMUNICATION
Table 2. Polymerization of allene derivatives catalyzed by the thiophene-fused cyclopentadiene ligated scandium complex 3 and post-functional scheme. [a]
Entry
1
Mon
A
Mon/Cat
200
500
100
100
100
100
500
100
100
100
100
100
100
50
T/℃
20
Time/h
24
Conv. (%)
94.6
82.4
94.8
72.8
86.6
85.1
91.2
83.8
81.9
89.1
82.4
0
1,2 %[b]
94
Mn[c]×10-4
2.2
3.6
1.9
3.7
4.6
7.6
25.6
1.1
5.1
1.4
5.0
-
PDI[c]
1.67
1.67
1.60
1.30
1.25
2.07
2.62
1.71
1.56
2.19
1.82
-
Tg/ Tm[d] (oC)
-27/-
-27/-
-27/-
-27/-
-27/39
-/39
2
A
A[e]
20
24
94
3
20
24
94
4
A
0
24
96
5
A
-20
-40
-40
20
36
98
6
A
36
>99
>99
94
7
A
96
-/39
8
B
24
-10/-
-/-
9
B
-40
20
36
>99
94
10
11
12
13
14
15
16
C
24
-32/-
-/-
C
-40
20
36
>99
-
D
24
-/-
E
20
24
0
-
-
-
-/-
Ff
G
G
20
96
41.9
78.7
65.8
13.0
84.0
>99
0.5
0.8
2.8
1.65
1.85
1.60
23/-
100
100
20
36
-2/-
-40
24
-2/-
[a] Conditions used for polymerization: [Sc] 10 μmol, [Ph3C][B(C6F5)4] 10 μmol, AliBu3 20 μmol, Toluene 0.2mL. The data in table are for the polymers before
post-functionalization. [b] Measured by 1H NMR in C6D4Cl2 at 100 oC [c] Determined by GPC in C6H3Cl3 at 150 oC against polystyrene standard. [d]
Determined by DSC. [e] [Sc] 10 μmol, [Ph3C][B(C6F5)4] 10 μmol, AliBu3 100 μmol. [f] [Sc] 20 μmol.
As compared to the extensive investigations on functionalizing
polyethylene via coordination polymerization of ethylene with
polar monomers,[3] that for polypropylene is rather rare. For one
reason, polypropylene cannot be prepared via radical
mechanism, which avoids radical copolymerization with vinyl
acetylacetate; another is effcient catalysts for propylene
coordination polymerization are very limited as compared to
those for ethylene polymerization, thus those can survive in the
copolymerization with polar monomers are scarce. The success
of highly 1,2-selective polymerization of the nonpolar allene
compounds stimulated us to attempt their copolymerization with
propylene using the excellent precursor 3. Unfortunately, trace
amount of polymer was obtained, which might be due to the
intense competition between the two monomers. Suprisingly to
us, complex 2a upon activation with [Ph3C][B(C6F5)4]
successfully aroused the copolymerization of allene monomer A
and propylene in a high activity comparable to that of propylene
homopolymerization and a rather high 1,2-selectivity (80%).
Meanwhile the allene incorporation was sensitive to the
propylene fraction in the reaction vessel, which increased with
the decreases of propylene pressure and reaction temperature
to reach up to 26.5% (Table 3). This meant a polypropylene
containing as as high as 26.5% molar fraction of hydroxyl groups
has been realized after post-functionalization, for the first time.
Scheme 1. Proposed mechanism for the polymerization of alkylallene monomers A, B, C and G by catalyst 3 (computed enthalpy of monomer B was
provided (kcal/mol)).
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10.1002/anie.201914747
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COMMUNICATION
Table 3. Copolymerization of n-decylallene and propylene by complex 2a and post-functional scheme. [a]
Entry
Propylene (atm)
T/℃
Time/h
Yield/g
Allene %[b]
1,2%[b]
Mn[c] ×10-4
PDI
Tg/Tm [d] (oC)
1
2
1
1
2
4
1
1
20
20
20
20
0
0.5
1
0.10
0.26
0.71
1.18
0.36
0.19
26.5
10.3
7.6
5.1
9.5
0
79
79
79
79
84
-
1.0
0.8
0.8
0.9
1.2
0.8
1.4
1.6
1.5
1.4
1.4
1.5
-40/-
-21/-
-17/-
-15/-
-19/3
-6/-
3
1
4
1
5
6[e]
3
20
1
[a] Conditions used for polymerization: [Sc] 10 μmol, Allene/[Sc]/[Ph3C][B(C6F5)4]=100:1:1 (mol/mol), Toluene, 2mL, Time, 1h, Temperature, r.t. The data in
table are for the copolymers before post-functionalization. [b] Measured by 1H NMR in CDCl3 at 25 oC. [c] Determined by GPC in THF at 40 oC against
polystyrene standard, [d] Determined by DSC, [e] Homopolymerization of propylene.
In summary, we have demonstrated that the unconventional
highly 1,2-selective polymerization of polar and nonpolar
alkylallene compounds can be achieved in high activity by using
the rare-earth metal based catalytic systems. These alkyl
substituted allene monomers are environmentally demanding,
thus, from catalytic precursor viewpoint, a more opening
coordination sphere is a precondition to show activity for allene
Wang, Y. Li, ACS Catal. 2018, 8, 5963; d) S. Li, D. Liu, Z.
Wang, D. Cui, ACS Catal. 2018, 8, 6086; e) L. Cui, M. Chen,
C. Chen, D. Liu, Z. Jian, Macromolecules 2019, 52, 7197.
[4] I. Moura, R. Nogueira, V. Bounor-Legare, A. V. Machado,
Mater. Chem.Phys. 2012, 134, 103.
[5] K. Iio, K. Kobayashi, M. Matsunaga, Polym. Advan. Technol.
2007, 18, 953.
polymerization.
The
half-sandwich
thiophene-fused
[6] a) M. B. Larsen, S. E. Herzog, H. C. Quitter, M. A. Hillmyer,
Acs. Macro. Letters. 2018, 7, 122; b) M. B. Larsen, S. J.
Wang, M. A. Hillmyer, J. Am. Chem. Soc. 2018, 140, 11911.
[7] D. Takeuchi, MRS Bull. 2013, 38, 252.
[8] a) J. Liu, Z. Han, X. Wang, Z. Wang, K. Ding, J. Am. Chem.
Soc. 2015, 137, 15346; b) T. M. Beck, B. Breit, Angew.
Chem. Int. Ed. 2017, 56, 1903; Angew. Chem. 2017, 129,
1929; c) Z. D. Miller, W. Li, T. R. Belderrain, J. Montgomery,
J. Am. Chem. Soc. 2013, 135, 15282.
cyclopentadienyl ligated rare-earth metal precursors are
sterically less bulky than the pyridinyl methylene fluorenyl and
the tridentate PNP ligated rare-earth metal precursors, which
exhibit higher activities. From allene monomer viewpoint, the
long alkyl chain or a terminal double bond cannot prohibit the
polymerization but the polar oxygen atom can terminate the
polymerization by chelating steadily to the active metal center.
With
respect
of
chemo-selectivity,
the
1,2-selective
polymerization is kinetically favored rather than the thermo
dynamical control. This work paves a new avenue to hydroxyl
modification of non polar polymers via copolymerization synthon
but to avoid the problem of catalysts being poisoned by the polar
groups. Now, the copolymerizations of allenes with styrene and
conjugated dienes and other simple olefins, are under
investigation.
[9] S. Kacker, A. Sen, J. Am. Chem. Soc. 1997, 119, 10028.
[10] M. Hong, B. Li, Y. Li, Chinese J. Polym. Sci. 2011, 29, 692.
[11] M. Taguchi, I. Tomita, T. Endo, Macromol. Chem. Physic.
2000, 201, 2322.
[12] a) A. Ding, G. Lu, H. Guo, X. Zheng, X. Huang, J. Polym.
Sci. Part A: Poly. Chem. 2013, 51, 1091; b) T. Takahashi, T.
Yokozawa, T. Endo, J. Polym. Sci. Part A: Poly. Chem.
1992, 30, 583.
Acknowledgements
This work is partially supported by the NSFC (projects Nos.
21634007, 21774118 and 21674108).
[13] a) K. Takagi, I. Tomita, T. Endo, Macromolecules 1997, 30,
7386; b) T. Kino, M. Taguchi, A. Tazawa, I. Tomita,
Macromolecules 2006, 39, 7474.
Keywords: allene • polar monomer • copolymerization •
hydroxylated polypropylene • rare-earth metal complex
References:
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Functionalized,
Crosslinkable,
Self-Healing
and
Photoresponsive Polyolefins, Angew. Chem. Int. Ed. DOI:
10.1002/anie.201910002; c) Y. Zhang, H. Mu, L. Pan, X.
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10.1002/anie.201914747
Angewandte Chemie International Edition
COMMUNICATION
For Table of Content Use Only
COMMUNICATION
The highly active and excellent 1,2-
selective coordination polymerization of
allenes has been achieved using rare-
earth metal precursors. The resultant
polyallens are facilely transferred into the
first poly(allyl alcohol) direvatives through
Yuanhao Zhong,[a,b] Iskander
Douair,[c] Tiantian Wang,[a,d]
Chunji
Wu,*,[a]
Laurent
Maron*,[c] and Dongmei Cui*,[a]
Page No.1 – Page No.5
hydroboration-oxidation
reactions.
Strikingly, the copolymerization of
A
Strategy
and
the
propylene and allene monomers are also
successul to afford the unprecedented
hydroxy functionalized polypropylene
after post-polymerization modification.
The mechanism elucidated by DFT
simulation suggests a kinetically favored
rather than thermo dynamical control
procedure.
Mechanism
Hydroxy
Polypropylene
to
Access
Functionalized
via
Coordination Polymerization
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