Novel titanium(IV) diolate complexes with additional O-donor as precatalyst for the synthesis of ultrahigh molecular weight polyethylene with reduced entanglement density: Influence of polymerization conditions and its implications on mechanical properties

Article abstract of DOI:10.1002/aoc.6256

New alkoxo-titanium(IV) complexes with diolate ligand containing additional donor oxygen atom have been synthesized from readily available and scalable precursors. The structure of complex 4 was established by X-ray diffraction. Titanium atom adopts a distorted tetrahedral geometry formed by six oxygen atoms of ligands. The resulting complexes 3–4 are moderately or highly active in ethylene polymerization in the presence of {Et_nAlCl_3–n + Bu₂Mg} binary cocatalysts. The influence of the nature of the solvent, the organoaluminum cocatalyst and the polymerization temperature on the activity of catalytic systems, and the properties of the resulting polymers were studied. The obtained polymers are linear polyethylene of ultrahigh molecular weight (up to 5.8·10⁶ g mol^?1) with a broad molecular weight distribution. The polymers are suitable for the modern methods of polymer processing—the solventless solid-state formation of super high-strength (breaking strength up to 2.8 GPa) and high-modulus (elastic modulus up to 140 GPa) oriented films and film tapes. The possibility of scaling up the synthesis of ultrahigh molecular weight polyethylene (UHMWPE) without a significant drop in the productivity of the catalytic system and polymer properties is shown. UHMWPE samples have been investigated by small-angle X-ray scattering (SAXS) methods to study the structural changes induced by solid-state drawing of nascent reactor powders.

Full text of DOI:10.1002/aoc.6256

Received: 25 January 2021
DOI: 10.1002/aoc.6256
Revised: 13 March 2021
Accepted: 22 March 2021
F U L L P A P E R
Novel titanium(IV) diolate complexes with additional
O-donor as precatalyst for the synthesis of ultrahigh
molecular weight polyethylene with reduced entanglement
density: Influence of polymerization conditions and its
implications on mechanical properties
Vladislav A. Tuskaev1,2
Vyacheslav S. Bogdanov2
Evgenii K. Golubev2,3
| Svetlana Ch. Gagieva1,2
| Dmitrii A. Kurmaev1
| Elena S. Mikhaylik2,3
| Galina G. Nikiforova2
|
|
| Kasim F. Magomedov1
|
| Mikhail I. Buzin2
Viktor G. Vasil'ev2
Artem V. Bakirov6,7
Boris M. Bulychev1
| Viktor N. Khrustalev3,4
| Pavel V. Dorovatovskii5,6
| Pavel B. Dzhevakov1
|
| Maksim А. Shcherbina3,6
|
1Department of Chemistry, M. V. Lomonosov Moscow State University, Moscow, Russian Federation
2A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russian Federation
3Department of Inorganic Chemistry, Peoples' Friendship University of Russia (RUDN University), Moscow, Russian Federation
4Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russian Federation
5Department of Synchrotron Experimental Stations, National Research Center “Kurchatov Institute”, Moscow, Russian Federation
6Laboratory of functional polymer structures, Enikolopov Institute of Synthetic Polymer Materials Russian Academy of Sciences, Moscow, Russian
Federation
7Department of Chemistry, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow, Russian Federation
Correspondence
New alkoxo-titanium(IV) complexes with diolate ligand containing additional
donor oxygen atom have been synthesized from readily available and scalable
precursors. The structure of complex 4 was established by X-ray diffraction.
Titanium atom adopts a distorted tetrahedral geometry formed by six oxygen
atoms of ligands. The resulting complexes 3–4 are moderately or highly active
in ethylene polymerization in the presence of {EtnAlCl3–n + Bu2Mg} binary
cocatalysts. The influence of the nature of the solvent, the organoaluminum
cocatalyst and the polymerization temperature on the activity of catalytic sys-
tems, and the properties of the resulting polymers were studied. The obtained
polymers are linear polyethylene of ultrahigh molecular weight (up to
5.8ꢀ106 g mol−1) with a broad molecular weight distribution. The polymers are
suitable for the modern methods of polymer processing—the solventless solid-
state formation of super high-strength (breaking strength up to 2.8 GPa) and
high-modulus (elastic modulus up to 140 GPa) oriented films and film tapes.
The possibility of scaling up the synthesis of ultrahigh molecular weight
Vladislav A. Tuskaev, PhD, Department of
Chemistry, M. V. Lomonosov Moscow
State University, 1 Leninskie Gory, 119992
Moscow, Russian Federation.
Email: tuskaev@tech.chem.msu.ru;
tuskaev@yandex.ru
Funding information
Russian Science Foundation, Grant/
Award Numbers: 18-13-00375,
16-13-10502; Russian Federation state
budget program, Grant/Award Number:
AAAA-A16-116053110012-5; Russian
Foundation for Basic Research, Grant/
Award Number: 19-03-00312; Ministry of
Science and Higher Education of the
Russian Federation using the equipment
of Center for molecular composition
studies of INEOS RAS
Appl Organomet Chem. 2021;e6256.
wileyonlinelibrary.com/journal/aoc
© 2021 John Wiley & Sons, Ltd.
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https://doi.org/10.1002/aoc.6256

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TUSKAEV ET AL.
polyethylene (UHMWPE) without a significant drop in the productivity of the
catalytic system and polymer properties is shown. UHMWPE samples have
been investigated by small-angle X-ray scattering (SAXS) methods to study the
structural changes induced by solid-state drawing of nascent reactor powders.
K E Y W O R D S
catalysts, titanium(IV) complexes, ultrahigh molecular weight polyethylene, Ziegler–Natta
polymerization
1 | INTRODUCTION
possibilities of solid-phase processing of such polymers
have not been studied.
Unique properties of ultrahigh molecular weight polyeth-
ylene (UHMWPE) make it one of the most promising
modern construction materials; however, the high viscos-
ity of its melts makes it difficult to use conventional
methods for its processing.[1,2] In this regard, the devel-
oped method of solid-phase processing of UHMWPE
reactor powders in high-strength films and tapes[3–7] is of
special importance. However, this method can be suc-
cessfully used only for processing of UHMWPE nascent
reactor powders with a morphology close to that of
single-crystal mats,[8] which can be synthesized on
single-site catalysts under mild conditions of polymeriza-
tion process (low concentrations of the catalysts and low
temperature and pressure).
In the overwhelming majority of cases, disentangled
UHMWPE suitable for solid-phase processing is synthe-
sized on phenoxy-imine Group 4 metal complexes
(FI catalysts[9]), activated with alkylaluminoxanes.[10–14]
However, these activators have significant drawbacks
that lie in the high Al/M ratios needed to achieve optimal
catalytic performance and in its still ill-defined structures
(mixture of oligomers (AlO(Alk))n evolving with time). In
addition, these activators increase considerably the cata-
lyst costs. In this regard, the development of precatalysts
for polyolefin synthesis that do not require the use of
expensive activators is an urgent task. The solution to this
problem will undoubtedly facilitate the wider introduc-
tion of nonmetallocene catalysis into industrial of
polyolefins.
Recently, it was shown that titanium(IV) alkoxide
complexes with 1,2-, 1,3-, and 1,4-diolate ligands (com-
pounds I–VII, Figure 1) activated by combination of
alkylaluminum chlorides and dibutylmagnesium can pro-
duce UHMWPE nascent reactor powders suitable for
processing into high-strength and high-modulus oriented
film tapes by the solvent-free method.[19–21]
In most cases, complexes with
a composition
LTi(OAlk)2 were obtained; however, in the case of con-
formationally more flexible 1,4-diolate ligands, the for-
mation of binuclear complexes of the composition
L3Ti2(OAlk)2 (compound V, Figure 1) was observed. It is
known that one of the ways to increase the stability of
the coordination compound is to introduce an additional
donor atom into the ligand structure. Tridentate chelat-
ing ligands, which possess three coordination sites and
six bonding electrons to coordinate a metal center, could
be considered as an alternative to the cyclopentadienyl
ligand.[22,23]
The fruitfulness of such an approach was shown in
Tuskaev et al.[24] and describing the synthesis of the
UHMWPE powders suitable for solid-phase processing
on titanium complexes with diolate ligands containing an
additional donor sulfur atom (compound VII, Figure 1).
In this work, we obtained precatalysts of the desired
LTi(OAlk)2 composition using tridentate diolate ligand
with an additional neutral donor oxygen atom, the struc-
ture of which suggests the formation of two stable five-
membered chelate rings.
An activating support of composition MgCl2/
AlRn(OEt)3–n or MgCl2/AlRnCl(OEt)2–n has been devel-
oped, which provides high activity of FI catalysts in the
The analysis of the literature data allows us to con-
clude that complexes stabilized with OOO2−-type ligands
are rarely used in postmetallocene catalysis. The exam-
ples of precatalysts for the ethylene polymerization are
shown in Figure 2.
A complex [OOO]TiCl2 (compound VIIIa, Figure 2)
activated by 10,000 equivalents of MAO revealed moder-
ate ethylene polymerization activity of 67 kg mol−1
(Ti) h−1; information on the activity of the spiro-complex
IX is not provided.[25] A dichlorotitanium complexes with
aryloxy-based OOO-type ligands (compounds Xa–b,
synthesis
of
UHMWPE
without
adding
methylaluminoxane (MAO).[15,16] A significant contribu-
tion to the development of nonmetallocene catalysts for
the synthesis of UHMWPE was made by the S. Mecking
scientific group who developed a new class of fluorine-
containing salicylaldiminato Ni(II) complexes capable of
synthesizing UHMWPE in polar solvents[17] including
water–mesitylene
suspensions.[18]
However,
the

TUSKAEV ET AL.
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FIGURE 1 Examples of Ti(IV) diolate olefin polymerization prеcatalysts
FIGURE 2 Examples of
Ti(IV) and V(V) complexes stabilized
by OOO-type ligands active in olefin
polymerization
Figure 2) in the presence of 500 eq. of MAO polymerize
ethylene with activity not exceeding 7–8 kg mol−1
(Ti) h−1.[26] A complex [cis-TiCl2(3-2,20-oxydiethanol)
(THF)] (compound XI, Figure 2) has been synthesized
and structurally characterized by X-ray diffraction
(XRD)[27]; however, the catalytic activity of this com-
activity towards ethylene polymerization and on proper-
ties of the polymers, including the ability to be processed
by a solid-state solventless method below its melting
temperature.
pound has not been investigated.
A
dichloro
2 | RESULTS AND DISCUSSION
oxovanadium(V) alkoxide complex XII with a similar
ligand environment, activated with diethyl aluminum
chloride as cocatalyst and in the presence of methyl
trichloroacetate as promoter, exhibits remarkably higher
2.1 | Ligands and coordination
compounds synthesis and structure
activity (445 kg mol−1 (V) h−1 bar−1
)
than VOCl3
Ligand 2 was synthesized by reacting of dimethyl 2,20-
oxydiacetate with phenyl magnesium bromide in diethyl
ether; its structure is confirmed by nuclear magnetic reso-
nance (NMR) spectroscopy data (Figures S1 and S2).
Reaction of Ti(OiPr)4 with the ligand 2 in a 1:1 mole ratio
led to the complex 3 (Scheme 1). Although we have
(360 kg mol−1 (V) h−1 bar−1
polymerization.[28]
)
towards ethylene
Therefore, the main purpose of this work is to investi-
gate the effect of an additional neutral donor oxygen
atom in the ligand environment of titanium(IV) on the

4 of 16
TUSKAEV ET AL.
SCHEME 1 Synthesis of diolate
ligand 2 and titanium(IV) complexes
3–4
therefore been unable to obtain single crystal suitable for
XRD, NMR and infrared (IR) spectroscopy data and ele-
mental analysis data do not contradict the assigned struc-
ture (Figures S3–S6).
Changing the ratio of reagents L:Ti(OiPr)4 to 1:0.5
leads to the formation of spiro-complex 4, which struc-
ture was unambiguously established by XRD study and is
shown in Figure 3 along with the atomic numbering
scheme. The pertinent bond lengths and angles are given
in Tables S1 and S2. The complex 4 crystallizes in the chi-
ral monoclinic space group P21, with the titanium atom
adopting the bicapped tetrahedral coordination geometry.
The O—CPh2—CH2—O—CH2—CPh2—O backbones
of the tridentate ligands have the g(+)–g(+)–t–g(+) and
g(−)–g(−)–t–g(−) conformations, respectively. The five-
membered chelate rings are in the usual envelope confor-
mations, with deviation of the O2/C3 and C29/C32 atoms
from the mean planes passed through the other atoms of
the rings. The angles between the basal planes of the che-
late rings for each of the ligands are 63.35(11)ꢁ and 55.74
(11)ꢁ, respectively. The Ti—O(1, 3, 4, 6) bond lengths of
1.841(3)–1.852(3) Å in 4 (Table S1) are very similar to
those observed previously in the related titanium com-
plexes.[29,30] The Ti—O2 and Ti—O5 distances of 2.383
(3) and 2.475(3) Å are quite different; that is due to the
differences in the conformations of the five-membered
chelate rings (see above). The O—Ti—O angles of 93.91
(12)–119.47(13) (Table S1) indicate a significant distortion
from ideal tetrahedral coordination of the titanium atom.
The packing of 4ꢀC7H8 in the crystal is stacked along
the crystallographic a axis (Figure S7). Note that the sol-
vate toluene molecules are located by the methyl groups
in the same direction. Apparently, it is the arrangement
of the solvate toluene molecules that determines the crys-
tallization of 4ꢀC7H8 in the chiral space group.
FIGURE 3 General view of molecule 4 in crystal in thermal
ellipsoid representation (p = 50%)
relevant results of ethylene polymerization using pre-
catalysts 3–4 are shown in Table 1. It was observed that
complexes 3–4 in the presence of Et2AlCl or Et3Al as
cocatalyst have demonstrated rather low catalytic activity
and yielded only the trace amounts of the polyethylene.
The introduction of dibutylmagnesium to the catalytic
systems containing aluminum alkyl chlorides leads to a
significant increase in activity (up to 2300 kg of PE mol−1
(Ti) h−1 atm−1, run 3).
To our surprise, the activity of the homoleptic com-
plex 4 without easily leaving ligands surpassed the activ-
ity of the heteroleptic complex 3. At the same time, the
molecular weights (MWs) of the polymer and the degrees
of crystallinity of the polyethylene samples obtained on
complex 3 significantly exceeded those obtained on the
spiro-complex 4. A similar pattern was observed by us
earlier, when homoleptic complexes with diolate ligands
III and VI (Figure 1) exhibit higher activity in ethylene
polymerization in comparison with heteroleptic dia-
lkoxotitanium complexes.[20,21]
2.2 | Catalytic properties of Ti diolate
complexes
All complexes reported herein have been tested for their
ability to catalyze the ethylene polymerization. The most

TUSKAEV ET AL.
5 of 16
TABLE 1 Ethylene polymerization by complexes 3–4a
[Ti],
Cocatalyst,
[Al]/[Mg]
T, ꢁ
C
Мv,d
106
Tme,
ꢁС
Deg. of
crystalf, %
Bulk density,
g cm−3
Entry Complex mol
Solv.b
Ac
1
3
3
4
4
3
3
3
3
3
3
3
3
3
3
5ꢀ10−6
5ꢀ10−6
5 10−6
5 10−6
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−5
1ꢀ10−4
Et2AlCl/Bu2Mg
300/100
T
30
30
30
30
20
30
40
50
60
30
20
30
30
20
1771 4.4
1429 5.8
2326 1.0
2286 3.7
1100 2.6
1157 2.0
1049 0.6
141/136 77/49
140/135 78/50
137/134 65/50
139/134 70/44
140/135 75/54
138/135 72/52
135/133 70/61
134/134 68/61
133/132 71/69
140/135 75/49
140/135 76/44
140/134 70/45
138/136 73/52
140/135 77/44
0.068
2
Et3Al2Cl3/Bu2M
300/100
T
T
T
T
T
T
T
T
P
P
N
0.074
0.075
0.089
0.068
0.073
0.059
0.075
0.084
0.066
0.072
0.069
0.099
0.058
3
Et2AlCl/Bu2Mg
300/100
4
Et3Al2Cl3/Bu2Mg
300/100
5
Et2AlCl/Bu2Mg
300/100
6
Et2AlCl/Bu2Mg
300/100
7
Et2AlCl/Bu2Mg
300/100
8
Et2AlCl/Bu2Mg
300/100
951
903
0.5
0.3
9
Et2AlCl/Bu2Mg
300/100
10
11
12
13
14
Et2AlCl/Bu2Mg
300/100
1429 2.9
571 4.8
1200 2.4
943 0.9
1000 4.1
Et2AlCl/Bu2Mg
300/100
Et2AlCl/Bu2Mg
300/100
Et2AlCl/Bu2Mg
300/100
T/P
1/1
Et2AlCl/Bu2Mg
300/100
T
aPolymerizations carried out in appropriate solvent at a constant 0.7-atm ethylene pressure for 30 min.
bT, toluene; P, petroleum ether; N, nefras.
cActivity, kg of PE mol−1 (Ti) h−1 atm−1
dMv was determined by viscosimetry.
.
eMelting points were determined by differential scanning calorimetry; the values for the first and second heating runs are given.
fDegree of crystallinity was calculated by the use of value Hm100% = 288 J g−1[[31]]; the values for the first and second heating runs are given (the differential
scanning calorimetry curves of ultrahigh molecular weight polyethylene samples are shown in Figures S8–S20).
We hypothesized that, unlike conventional
alkoxotitanium complexes (e.g., 3), cleavage of the Ti—O
bonds in the spiro-complex 4 in the presence of an
organoaluminum activator can lead to the formation of
hetero-bimetallic Ti—Al complexes and further zwitter-
ionic bimetallic complexes as the catalytically active spe-
cies. A similar pattern of the activation of alkoxo-
titanatranes is considered in Wang et al.[32] The increase
in the activity of titanatranes when small amounts of
Me3Al are added to the activator MAO led the authors to
the hypothesis of the formation of a hetero-bimetallic
Ti—Al complexes, which was later proved experimen-
tally (Scheme 2).[33]
Speaking about the influence of the nature of the
organoaluminum activator, it can be noted that the previ-
ously observed trend that the catalytic systems containing
Et2AlCl are more active,[19–21] while the use of Et3Al2Cl3
is accompanied by a significant increase in the MW of
the polymer, also manifests itself in this work.
In order to produce polymer samples in quantities
sufficient for carrying out physical and mechanical tests,
the catalyst concentration was increased to 1ꢀ10−5 mol
(Entries 5–13).
It is known that the polymerization temperature has
a significant effect on the MW of UHMWPE. In most
cases, its growth leads to a decrease in MW, for example,

6 of 16
TUSKAEV ET AL.
SCHEME 2 The proposed mechanism of
activation of titanatranes in the presence of
small amounts of Me3Al (top) and spiro-
complex 4 (bottom)
Joo et al.[34] Figure 4 shows the dependence of the activ-
ity of the catalytic system {3/Et2AlCl/Bu2Mg} and the
MW of the obtained polymers on the polymerization tem-
perature. An increase in the synthesis temperature from
20ꢁС to 60ꢁС leads to a gradual decrease in the MW of
the resulting polymers (Table 1, Entries 5–9, Figure 4).
However, the use of toluene as a reaction medium is
not very advisable for both environmental and economic
reasons. Experiments 10–12 (Table 1) showed the possi-
bility of replacing the solvent with petroleum ether or
nefras (the petroleum fraction consisting of aliphatic
hydrocarbons and boiling in a wider range 50–170ꢁC and
commonly used as an industrial solvent) without signifi-
cantly reducing the productivity of the studied catalyst
systems. Moreover, the replacement of the solvent leads
to a rather noticeable increase in the Mv of the polymer
(Figure 5). It was shown in Forte and Ronca[35] that the
use of mixtures of aromatic and aliphatic solvents in the
synthesis of UHMWPE allows a sufficiently wide range
to regulate the mechanical characteristics of the obtained
polymers. In our case (Entry 13, Table 1), the use of sol-
vent mixtures did not lead to an increase in activity or a
noticeable improvement in the properties of the
polymers.
FIGURE 4 Dependence of the activity of the catalytic system
3/Et2AlCl + Bu2Mg and the molecular weights of the resulting
polymer on the polymerization temperature
2.3 | Rheological and thermal properties
Studying the rheological characteristics of a polymer melt
is a convenient and rapid method for determining MWs.
In addition, rheological experiments are perhaps the only
method that makes it possible to estimate the MW distri-
bution of high MW polymers for which the method of gel
permeation chromatography is inapplicable.[36] The
determination of MWs of UHMWPE samples by the rhe-
ological method in the absence of a solvent is signifi-
cantly hampered by thermal oxidation processes that
Experiment 14 was carried out in a 5-L reactor in
order to demonstrate the possibility of producing a large
batch of polymer. Taking into account the possibility of
deactivation of the complex when using large volumes of
solvent, its concentration was increased to 10−4 mol. As
can be seen from the results presented in Table 1, scaling
did not lead to significant changes in the values of the
activity of the system and the properties of the polymers.

TUSKAEV ET AL.
7 of 16
FIGURE 5 The effect of the
nature of the solvent on the
catalytic activity 3/Et2AlCl
+ Bu2Mg and molecular weights
of ultrahigh molecular weight
polyethylene samples
begin at relatively low temperatures, immediately after
the polymer melts.[2] For this reason, such studies are
carried out at 200ꢁC with the addition of antioxidant
Irganox 1010, frequently used in the UHMWPE melt
processing.[37–40] To determine the optimal amount of
antioxidant, we studied samples of the UHMWPE reactor
powder treated with antioxidant Irganox 1010 in an
amount of 0.1–0.6 wt.% by differential scanning calorime-
try (DSC), thermogravimetric analysis (TGA), and
thermomechanical analysis (TMA) methods. For these
experiments, we used a UHMWPE sample obtained by
scaling up the synthesis in an amount of 50 g (Entry
14, Table 1).
From the first heating curves of DSC cycles, the
nascent UHMWPEs demonstrate extremely high melting
points (133–141ꢁC) and crystallinities (65%–78%). These
values noticeably decrease at the second heating run,
which is typical for UHMWPE (Figures S8–S20).
FIGURE 6 Thermomechanical analysis and differential
scanning calorimetry curves for ultrahigh molecular weight
polyethylene (Entry 14, Table 1) with different contents of
Irganox 1010
The DSC study showed that the treatment of the poly-
mer with the Irganox 1010 does not affect the melting
temperature of the sample (Figure 6). On the DSC curves
above the endothermic melting peak, an exothermic peak
appears, which corresponds to the processes of low-
temperature oxidation of UHMWPE—the formation of
peroxide compounds.[41] The maximum of this peak
shifts to the region of higher temperatures as the content
of the antioxidant increases (Figure 6). On the TGA cur-
ves (Figure 7), this process manifests itself in the appear-
ance of a mass gain area (up to 1%). The amount of
weight gain decreases as the amount of the introduced
antioxidant increases and the range in which it appears
shifts towards higher temperatures. Obviously, the
decrease in the weight gain is associated with the acceler-
ated transformation of the formed peroxide radicals at
elevated temperatures into volatile products of the ther-
mal decomposition of UHMWPE—ketones, esters, lac-
tones, and carboxylic acids.[2]
TMA (Figure 6) showed that in the temperature range
of 25–350ꢁC, the deformation of UHMWPE develops in
two stages. The first of them, including 65%–70% of the
deformation value, is located in the region of 140ꢁC, that
is, near the melting point of UHMWPE. After that, the
thermomechanical curve reaches a plateau, the length of
which increases with an increase in the content of
Irganox 1010. The second stage of the deformation is
much less (5%–8%); it coincides on the temperature scale
with the position of the exothermic peak on the DSC

8 of 16
TUSKAEV ET AL.
curves, that is, with the temperature range of low-
temperature thermo-oxidative processes in UHMWPE. At
the end of this stage of the plastic deformation, the TMA
curves again reach a plateau, continuing up to a tempera-
ture of 400ꢁC, when the main stage of the UHMWPE
decomposition begins, accompanied by an intense loss of
sample mass.
The frequency dependences of the storage modulus
(G0) and the loss modulus (G00) for UHMWPE samples
treated with different amounts of Irganox 1010 indicate
that the G0 value increases with an increase in the con-
tent of antioxidant from 0.1 to 0.6 wt.% (Figure 8). This
indicates a decrease (or disappearance) of melt destruc-
tion processes that lead to a decrease in MW. This effect
grows very rapidly in the range of 0.1–0.3 wt.% and prac-
tically reaches “saturation” at 0.6 wt.% of the antioxidant.
In the sample containing 1% Irganox 1010, the values of
G0 and G00 are lower than in the others, which is possibly
already associated with its plasticizing effect.
For all studied samples, the values G0 > G00, and there
are no crossover points (G0 = G00); therefore, after melt-
ing, the polymer does not go into a viscous-flow state but
is an elastomer (Figure 8). This character of the fre-
quency dependences of G0 and G00 is typical for
UHMWPE,[42,43] and the absence of a high elasticity pla-
teau in the presented dependences indicates the absence
of an equilibrium entanglement network.
In the absence of a crossover point, the MW of the
polymer can be determined from the frequency depen-
dence of the complex viscosity (Figure S21). The values of
η* at zero frequency were calculated using approximation
of frequency dependences of complex viscosity η* at
200ꢁС by the Carreau–Yasuda equation[44]
:
ðn−1Þ=a
a
ηꢂðωÞ = η∞ + ðη0 −η∞Þð1 + ðλωÞ Þ
,
ð1Þ
where η is viscosity at zero shear rate, η∞ viscosity at infi-
nite shear rate, λ relaxation time, n power law index, and
a dimensionless parameter (2 in most cases).
From this dependence (determined for a sample con-
taining 0.6% antioxidant at 200ꢁC, Figure 8), the value
[η]o at zero frequency, 4,2439E+7 Pa s−1, was deter-
*
mined using the Carreau–Yasuda equation. Zero viscosity
*
[η]o calculation was performed using the software sup-
FIGURE 7 Thermogravimetric analysis curves for the
ultrahigh molecular weight polyethylene reactor powder (Entry
14, Table 1) with different contents of Irganox 1010
plied with the Anton Paar rheometer.[45] From the
dependence of viscosity on MW for polyethylenes given
in Shaw,[46] the studied sample corresponds to the value
of 4ꢀ106 Da, which is very good agreement with the MW
determined by the viscometric method (Table 1,
Figure S21).
2.4 | Mechanical properties of
synthesized UHMWPE
The processing of reactor powders of UHMWPE obtained
on complexes 3–4 into high-modulus oriented films was
carried out by preparing monolithic samples under pres-
sure and shear deformation at temperatures lower than
the main melting peak with subsequent uniaxial draw-
ing.[8] Criteria for the quality of the resulting oriented
film tapes were the homogeneity of the resulting filament
along the width and the homogeneity of the sample's
masses within one multiplicity at one length. The
mechanical properties of oriented film tapes obtained
from the tensile test are given in Table 2.
FIGURE 8 Frequency dependences G0 (full) and G00 (open) for
UHMWPE Sample 14 treated with 0.1%, 0.3%, 0.6%, and 1% Irganox
1010 solution

TUSKAEV ET AL.
9 of 16
As can be seen, the best mechanical characteristics
UHMWPE. It is shown that reducing the particle size
decreases the fusion defects and grain boundaries in
compression-molded UHMWPE samples[47] reported that
UHMWPE particles with smaller size show a faster
sintering rate.
The method of the laser diffraction in a suspension of
UHMWPE powders has been successfully used to esti-
mate particle size and uniformity.[48] Figure 9 shows the
distribution of the powder's particle size of UHMWPE
samples in the Experiments 2, 3, and 14 (Tables 1 and 2).
The sample of the UHMWPE reactor powder obtained by
scaling up the synthesis (Entry 14) is characterized by the
smallest particle size and the narrowest particle distribu-
tion in this series. These results correlate well with the
excellent mechanical characteristics of the oriented film
obtained from this sample.
were shown by the UHMWPE samples synthesized at the
heteroleptic complex 3. The replacement of Et2AlCl by
Et3Al2Cl3 in the binary activator (Entries 2 vs. 1) leads to
an insignificant improvement in the mechanical proper-
ties (possibly due to the different MWs of the polymers—
4.4ꢀ106 and 5.8ꢀ106). The samples of UHMWPE synthe-
sized in petroleum ether (Entries 10 and 11) are inferior
to analogs obtained in toluene in terms of the drawing
ratio. However, the samples obtained in the higher boil-
ing aliphatic hydrocarbon solvent, nefras (Entry 12),
reached a draw ratio of 32, the maximum in this series of
experiments. The polymer samples obtained on the
homoleptic complex 4, activated with Et3Al2Cl3, showed
the worst results in this series, whereas the polymer
obtained on 4/Et2AlCl/Bu2Mg turned out to be
unsuitable for the solid-phase processing. It is important
to note that scaling up the UHMWPE synthesis on a cata-
lytic system {3/Et2AlCl/Bu2Mg} practically did not affect
the mechanical characteristics of the polymer (Entries
1 and 14, Table 2).
It is well known[49] that the drawability of UHMWPE
highly depends on its supramolecular structure. To exam-
ine the morphologies of these powders, scanning electron
microscope (SEM) observations have been made
(Figure 10). As can be seen from the scanning electron
micrographs at low magnification, the polymer particles
have the irregular shape and porous structure, which
determines the low bulk density (0.058–0.099 g cm−3) of
the obtained samples.
In addition to the high MW and low degree of entan-
glement of macromolecules, the particle size, uniformity,
and morphology of the reactor powder will also affect the
strength characteristics of oriented materials from
TABLE 2 Mechanical properties of
Entry
Catalytic systemb
Draw ratio
28–32
28–32
16–20
20–24
28
σc, GPa
2.5–2.6
2.6–2.8
1.9–2.7
2.3–2.5
2.2–2.5
1.9–2.1
2.3–2.5
Ed, GPa
130–132
132–140
90
εe, %
ultrahigh molecular weight
polyethylene-oriented film tapesa
1
3/Et2AlCl/Bu2Mg 300/100
3/Et3Al2Cl3/Bu2Mg 300/100
4/Et3Al2Cl3/Bu2Mg 300/100
3/Et2AlCl/Bu2Mg 300/100
3/Et2AlCl/Bu2Mg 300/100
3/Et2AlCl/Bu2Mg 300/100
3/Et2AlCl/Bu2Mg 300/100
2.31–2.40
2.50–2.57
1.62–2.14
2.45–2.66
2.33–2.73
2.80–2.90
2.39–2.48
2
4
10
11
12
14
124–125
124–129
94–103
135–137
28–32
28–32
aNumbering corresponds to Table 1.
bDraw ratio, the degree of elongation during uniaxial drawing.
cσ, tensile strength, GPa.
dE, average tensile modulus, GPa.
eε, elongation at break, %.
FIGURE 9 Particle size distribution of ultrahigh molecular weight polyethylene powders obtained in the Experiments 2, 3, and 14

10 of 16
TUSKAEV ET AL.
At high magnification, most samples have nodular
It is important to note that during the formation of
UHMWPE fibers, small amounts of the monoclinic phase
manifesting itself by the weak 010 reflection (d-spacing of
4.47 Å) are also observed.[50] It is also important to note
that the intensity ratio of the most intense reflections
I110/I200 varies significantly from sample to sample and
correlates to the degree of drawing ratio (Figure 12). A
detailed study of the obtained UHMWPE tapes allows us
concluding that they are characterized by the c-axis tex-
ture. On the diffractograms of non-oriented UHMWPE
film, reflection 200 disappears almost completely due to
the presence of the a-plane texture. Due to the presence
type microstructures. However, for the sample with the
worst mechanical properties (Entry 3, Table 1), the parti-
cles look fused and connected by a large number of
fibrils, forming a “cobweb” structure.
The samples of UHMWPE films with different draw-
ing ratios and a tape monolithized on rollers (non-
oriented) were studied by X-ray structural analysis.
Two-dimensional XRD patterns (Figure 11) reveal at least
six reflections of the orthorhombic lattice, two of them
(110 and 200) being equatorial and four (020, 310,
111, and 201) meridional.
FIGURE 10 Scanning electron microscope (SEM) images of the surface morphology of ultrahigh molecular weight polyethylene
powders obtained with catalytic system 3/EtAlCl2/Bu2Mg (Entry 14, Tables 1 and 2) and 4/EtAlCl2/Bu2Mg (Entry 3, Table 1)
FIGURE 11 Two-dimensional X-ray scattering patterns for oriented films with draw ratios 20, 24, 28, 32, and non-oriented film. The
orientation axis is vertical

TUSKAEV ET AL.
11 of 16
of the aforementioned texture types, quantitative analysis
of the degree of the crystallinity of the samples by the
XRD method is impossible. However, estimations are
above 90% for all the studied films, and above 80% for
non-oriented UHMWPE film. Moreover, high degree of
ordering of the material is justified by the significant lon-
gitudinal crystallite size calculated with the use of
Scherer formula. Its value amounts at least 15 nm (see
Table 3), which corresponds to approximately 40 polymer
chains[51] and the factor of their orientation.
Important information on the structure of the poly-
meric material (periodicity of lamellar packing and frac-
tal size of domains) can be obtained from the small-angle
X-ray scattering (SAXS). Figure 13 reveals an intense
equatorial stroke, indicating a high orientation of the
pores. It is important to note the absence of the meridio-
nal scattering (long spacing) corresponding to variations
in the electron density along fiber fibrils.
This fact can be explained either by the extremely
high crystallite size along the fibrils (the formation of
extended chain crystals) or by the low variation of the
electron density between amorphous and crystalline
phases in the fibrils, associated with a high density of
passing chains in the amorphous phase.
3 | CONCLUSIONS
In summary, new titanium(IV) complexes bearing OOO2
−-type diolate ligand have been synthesized. The struc-
ture of homoleptic complex 4 has been established
by XRD.
All complexes in the presence of a binary cocatalysts
{3Et2AlCl + Bu2Mg} or {1.5Et3Al2Cl3 + Bu2Mg} exhibited
moderate to high activities towards ethylene polymeriza-
tion (570–2330 kg of PE mol−1 (Ti) h−1 atm−1). The MWs
of obtained polymer samples reached 5.8ꢀ106 Da.
FIGURE 12 Wide-angle X-ray diffraction patterns of oriented
tapes with different draw ratios (Equatorial scans of diffractograms.
For clarity, the curves are shifted along Oy axis. Reflections of the
orthorhombic lattice of polyethylene [PE] 110 and 200 are marked.)
TABLE 3 Parameters of ultrahigh molecular weight polyethylene crystallites
Draw ratio
Misorientation, deg
Preferred orientation, %
L sherrer(110), nm
0 (non-oriented film)
17.24
2.64
5.12
2.44
4.12
90.4
98.5
97.2
98.6
97.7
15.0
17.2
16.6
14.8
16.8
22
24
28
32
FIGURE 13 Two-dimensional small-angle X-ray scattering patterns for Samples 20, 24, 28, 32, and the non-oriented tapes. The
stretching direction is close to vertical; background was subtracted

12 of 16
TUSKAEV ET AL.
The UHMWPE nascent reactor powders were
laboratory at A. N. Nesmeyanov Institute of
Organoelement Compounds.
processed by a solvent-free method into high-strength
(up to 2.8 GPa) and high-modulus (up to 140 GPa)
oriented film tapes. Comparing the results obtained with
previously published data on the Ti diolate complexes
(containing no perfluorinated fragments),[19–21,24] it can
be noted that the introduction of an additional donor atom
does not increase the catalytic activity but significantly
improved the mechanical characteristics of oriented films.
The mechanical characteristics of the obtained oriented
UHMWPE films do not surpass to the best published data
(e.g., disentangled UHMWPE obtained on the bis[(3-tert-
butylsalicylidene)pentafluoroanilinato]titanium
Toluene was distilled over Na/benzophenone ketyl,
and the water content was periodically controlled by
Karl-Fischer coulometry by using a Methrom 756 KF
apparatus. Diethylaluminum chloride, ethylaluminum
sesquichloride, and di-n-butylmagnesium (Aldrich) were
used as 1.0-M solution in heptane. 2,20-Oxydiacetic acid
was obtained by oxidation of diethylene glycol with nitric
acid.[54]
4.1 | Dimethyl 2,20-oxydiacetate (1)
(IV) dichloride activated with 1000 eq. of MAO has been
converted to the solid-state drawn tapes with the tensile
strength up to 3.8 GPa and tensile modulus over
165 GPa[5]). We presume that optimizing of solid-phase
processing conditions (e.g., biaxial or multistage
stretching,[52] or orientational stretching in the zone-
drawing regime[53]) allows to significantly improve the
mechanical properties of oriented materials.
The most significant advantage of the catalytic sys-
tems considered in this work is the simplicity of the pre-
catalyst's synthesis and the possibility of their activation
with conventional organoaluminum compounds in the
low Al/M ratios (MAO-free catalytic system). The possi-
bility of replacing an aromatic solvent—toluene—with
aliphatic ones, as well as scaling up polymer synthesis
without a significant drop in the productivity of the cata-
lytic system and polymer properties, is shown. The
UHMWPE samples have been investigated by SAXS
methods to study the structural changes induced by
solid-state drawing of nascent reactor powders.
2,20-Oxydiacetic acid (2.0 g, 0.015 mol) and SOCl2 (40 ml,
0.55 mol) were stirred at room temperature for 8 h; then
the dry methanol (40 ml) was added dropwise to the mix-
ture. After stirring overnight, it was quenched with satu-
rated solution of NaHCO3 and then twice with water. The
collected organic phase was dried over anhydrous magne-
sium sulfate and concentrated in vacuum. The resultant
oil was dried under high vacuum to obtain 2.36 g (98%) of
dimethyl 2,20-oxydiacetate as a crystalline, white solid. 1H
NMR (400 MHz, CDCl3, ppm): δ 3.72 (s,6H), 4.20 (s, 4H);
13C NMR(100 MHz, CDCl3): δ 48.28, 51.88, 170.02.
4.2 | 1,1,1010-Tetraphenyl-2,20-
oxydiethanol (2)
To a solution of PhMgBr (80 mmol) in Et2O, prepared
from magnesium (2.32 g, 96 mmol) and bromobenzene
(10.05 ml, 80 mmol), an ethereal solution of dimethyl
2,20-oxydiacetate (2.43 g; 15 mmol) was added dropwise
at 0ꢁС. The reaction mixture was allowed to slowly warm
to room temperature, then it was stirred overnight and
quenched with aq. NH4Cl solution, and the product was
extracted with diethyl ether. The combined organic phase
was dried over Na2SO4, and the solvent was removed
under reduced pressure. Recrystallization of the crude
product from hexane/toluene gave 3.24 g (78%) of a color-
less solid. Calculated (%) for C28H26O3 (410.5): C,
4 | EXPERIMENTAL
All manipulations with air-sensitive materials were per-
formed with the rigorous exclusion of oxygen and mois-
ture in oven-dried Schlenk glassware on a dual manifold
Schlenk line, interfaced to a high-vacuum line. Argon
and ethylene of special-purity grade (Linde gas) were
dried by purging through a Super Clean™ Gas Filters.
NMR spectra were recorded on Bruker AMX-400
instrument. Deuterated solvents (CDCl3, d8-THF) were
degassed by freeze-pump-thaw vacuum cycles and stored
over 3-Å molecular sieves. Chemical shifts are reported
in ppm versus SiMe4 and were determined by reference
to the residual solvent peaks. All coupling constants are
given in Hertz. Air-sensitive NMR spectra were taken in
J. Young tubes with Teflon valve plugs. IR spectra were
recorded on a Magna-IR 750 spectrophotometer. Elemen-
tal analysis was performed by the microanalytical
1
81.92; H, 6.38. Found (%): C, 81.89; H, 6.34. H NMR
(400 MHz, CDCl3, ppm): δ (m,4H), 4.20 (m, 20H); 13C
NMR(100 MHz, CDCl3): δ: 144.30, 144.16, 128.32, 127.31,
127.04, 126.77, 126.56, 78.03, 77.71 (Figures S1 and S2).
4.3 | (1,1,1010-Tetraphenyl-2,20-oxy-1,10-
diolate)-bis-(isopropoxy)-titanium (3)
Compound 2 (0.42 g, 1 mmol) and toluene (20 ml) were
placed into a Schlenk tube equipped with a magnetic

TUSKAEV ET AL.
13 of 16
stirrer under an argon atmosphere, followed by the addi-
tion of Ti(OiPr)4 (0.296 ml, 1 mmol) at room temperature.
The resulting suspension was heated until all solids dis-
solved. After 20 h at room temperature, the formed crys-
tals were collected by filtration and dried in vacuo. Yield
0.51 g (72.9%). Calculated (%) for C34H38O5Ti (574.53): C,
71.08; H, 6.67; Ti, 8.33. Found (%): C, 70.99; H, 6.62; Ti,
8.28. 1H NMR (400 MHz, d8-THF): δ = 7.42–7.05 (m,
20H), 4.61 (s, 2H), 3.81 (s, 4H, CH), 3.58 (s, 4H, OH), 1.12
(s, 12H, CH3), 1.09 (s, 12H, CH3). 13C NMR (101 MHz, d8-
THF) 188.57, 147.16, 146.05, 127.91, 127.39, 126.55, 89.58,
87.65, 82.35, 81.23, 78.47, 77.87, 67.57, 63.72, 63.40. IR
(KBr, ν, cm−1), 486 (Ti—O) (Figures S3 and S4).
1.2Ueq(C) for the other groups]. The absolute structure of
4ꢀC7H8 was objectively determined by the refinement of
Flack parameter, which became equal to 0.011(6). All cal-
culations were carried out using the SHELXTL program
suite.[57] Crystallographic data for 4ꢀC7H8 have been
deposited with the Cambridge Crystallographic Data
Center, CCDC 1823041. The supplementary crystallo-
graphic data can be obtained free of charge from the
Cambridge Crystallographic Data Centre via www.ccdc.
cam.ac.uk/data_request/cif.
4.6 | Polymerization of ethylene
The ethylene polymerization was performed in a 100-ml
reactor (Parr Instrument Co.) equipped with a magnetic
stirrer and inlets for loading components of catalytic sys-
tems and ethylene at a total pressure of ethylene and
toluene vapors of 0.7 atm. Toluene (50 ml) and the neces-
4.4 | Bis-(1,1,1010-tetraphenyl-2,20-oxy-1,10-
diyloxy)titanium (4)
Prepared similar to compound 3. The following amounts
were taken: ligand 2 (0.42 g, 1 mmol) and Ti(OiPr)4
(0.148 ml, 0.5 mmol). Yield 0.30 g (69%). Calculated (%)
for C56H48O6Ti (864.84): C, 77.77; H, 5.59; Ti, 5.53. Found
sary amount of
a
cocatalyst (Et2AlCl/Bu2Mg or
Et3Al2Cl3/Bu2Mg) were loaded in the reactor. The reactor
was heated to a specified temperature, and the reaction
mixture was saturated with ethylene. Polymerization was
started by the addition of precatalyst to the reaction mix-
ture. The pressure of ethylene was maintained constant
during polymerization. Polymerization was stopped
through the addition of 10% HCl solution in ethanol to
the reactor. The polymer was filtered off, washed several
times with water–ethanol mixture, and dried under
vacuum at 50–60ꢁC until a constant weight was achieved.
Experiment 14 was carried out in a 5-L reactor using
a similar procedure.
1
(%): C, 77.72; H, 5.54; Ti, 5.50. H NMR (400 MHz, d8-
THF): δ = 7.94–7.67 (m, 20H), 4.53 (s, 4H). 13C NMR
(101 MHz, d8-THF): δ = 196.97, 144.40, 144.17, 144.14,
134.40, 133.95, 128.88, 128.24, 128.20, 127.83, 127.34,
127.30, 127.19, 126.70, 126.67, 126.58, 126.54, 78.60,
73.91. IR (KBr, ν, cm−1), 459 (Ti—O) (Figures S5–S7,
Tables S1 and S2).
4.5 | X-ray crystal structure
determination
The single-crystal XRD data for 4 were collected on the
“Belok” beamline of the Kurchatov Synchrotron Radia-
tion Source (National Research Center “Kurchatov Insti-
tute”, Moscow, Russian Federation) using a Rayonix
SX165 CCD detector at λ = 0.96990 Å. A total of
720 images for two different orientations of the crystal
were collected using an oscillation range of 1.0ꢁ and φ
scan mode (Table S1). The data were indexed and inte-
grated using the utility iMOSFLM from the CCP4 pro-
gram suite[55] and then scaled and corrected for
absorption using the Scala program.[56] For details, see
Table 2. The structure was solved by direct methods and
refined by a full-matrix least square technique on F2 in
anisotropic approximation for nonhydrogen atoms. The
independent part of the unit cell of 4 contained a toluene
solvate molecule. The hydrogen atoms in 4ꢀC7H8 were
placed in calculated positions and refined within the rid-
ing model with fixed isotropic displacement parameters
[Uiso(H) = 1.5Ueq(C) for the methyl groups and
4.7 | Polymer evaluation methods
DSC was performed by a differential scanning calorime-
ter DSC-822e (Mettler-Toledo, Switzerland) at a heating
rate 10ꢁC min−1 in air and in argon.
TGA measurements were done by a “Derivatograph-
C” (MOM, Hungary) at a heating rate 10ꢁC min−1 in air.
TMA was carried out by TMA Q400 (TA Instruments,
USA) on powder samples at a heating rate 5ꢁС min−1
and a share stress 1 N in air.
Viscosity-average MW of synthesized UHMWPE sam-
ples was calculated with the Mark–Houwink equation:
Mv = 5.37ꢀ104 [η]1.37 [2]
,
where Mv = viscosity-average
MW (g mol−1); [η] = intrinsic viscosity in decalin at
135ꢁC (dl g−1); and [η] = (2ηsp − 2lnηr)1/2/0.056 (ηsp, spe-
cific viscosity decalin at 135ꢁC; ηr, relative viscosity in
decalin at 135ꢁC; ηr = ηsp + 1).
The mechanical characteristics of the oriented mate-
rials prepared with the synthesized polymers were

14 of 16
TUSKAEV ET AL.
evaluated on the oriented tapes obtained by a solid-state
processing of UHMWPE nascent reactor powders. The
uniform over the entire length monolithic tapes (100 mm
in thickness and 10 mm in width) were formed at a pres-
sure and shear deformation below the polymer melting
point (124–126ꢁC). The tapes were subjected to uniaxial
drawing while using a Spinline Daca equipment. The
drawing temperature was set 4ꢁC below the polymer
melting point. The mechanical characteristics of the tapes
were measured with a Hounsfield H1KS machine at the
gauge length of the tested samples 120 mm with
2 mm min−1 initial deformation rate. The reported values
were the average of at least eight samples.
for Molecular Composition Studies of INEOS RAS. The
synthesis of Catalyst 2 was supported by the Russian
Foundation for Basic Research (Project No. 19-03-00312).
DSC results were obtained on the equipment of the
Educational and Scientific Centre of Functional and
Nanomaterials, Moscow Pedagogical State University,
with the financial support from Ministry of Science
and Higher Education of the Russian Federation.
Studies of the morphology of UHMWPE nascent reactor
powders were supported by the Russian Federation
state budget program (Federal Registration AAAA-
A16-116053110012-5).
Rheological experiments were performed using a
25-mm parallel plate strain controlled rheometer MCR-
302 Anton Paar in sinusoidal oscillation mode. The
nascent powder was compressed into a plate of 50 mm
diameter and thickness of 0.7–0.8 mm at a fixed tempera-
ture of 25ꢁC, under a maximum force of 15 tons for an
average time of 5 min. From the compressed plate,
25-mm-diameter disks were cut for rheological studies.
The disc was placed between parallel plates at an initial
temperature of 160ꢁC. The following parameters were
measured: the storage (elastic) modulus, G0, and the loss
modulus, G00. These parameters represent the relative
degrees of the material to recover (elastic response) or
flow (viscous response), respectively. Particle size analysis
of UHMWPE nascent reactor powders was carried out
with laser diffraction particle size analyzer Mastersizer
3000 (Malvern Instruments, Malvern, UK). The sample
dispersion in acetone was prepared in the Hydro EV
device at room temperature and 1500 rpm.
AUTHOR CONTRIBUTIONS
Vladislav Tuskaev: Conceptualization; investigation;
methodology. Svetlana Gagieva: Data curation; investi-
gation; resources. Dmitry Kurmaev: Conceptualization;
formal analysis; investigation; resources. Vyacheslav
Bogdanov: Formal analysis; investigation. Kasim
Magomedov: Formal analysis; software; validation.
Elena Mihaylik: Formal analysis; resources. Evgenii
Golubev: Formal analysis; resources. Mikhail Buzin:
Conceptualization; investigation; project administration.
Galina Nikiforova: Formal analysis; methodology; vali-
dation; visualization. Viktor Vasil’ev: Conceptualiza-
tion; funding acquisition. Victor Khrustalev:
Conceptualization; investigation. Pavel Dorovatovskii:
Resources; visualization. Artem Bakirov: Investigation;
resources; validation. Мaksim Shcherbina: Formal
analysis; investigation. Pavel Dzhevakov: Formal analy-
sis. Boris Bulychev: Data curation; project administra-
tion; supervision.
SAXS/wide-angle X-ray scattering (WAXS) tech-
niques were utilized to study samples of polyethylene
fibers of various drawing ratios and a tape monolithized
on rollers. The studies were performed at the BioMur sta-
tion of the Kurchatov synchrotron. The wavelength was
DATA AVAILABILITY STATEMENT
The data that support the findings of this study are avail-
able in the supporting information of this article.
0.1445 nm (8 keV), the energy resolution dE/E was 10−3
,
ORCID
and the photon flux and the beam size on the sample
were 109 and 300 × 200 μm, respectively. To record dif-
fraction patterns, a two-dimensional detector Dectris
Pilatus 1 M was used. The distance of the sample detector
was 170 and 2200 mm. Silver behenate was used as the
calibration standard. The software packages Fit2D and
ImageJ were used to process the obtained scattering pat-
terns. The exposure time was 300 s.
Vladislav A. Tuskaev https://orcid.org/0000-0001-7182-
462X
Svetlana Ch. Gagieva https://orcid.org/0000-0003-4654-
9974
Dmitrii A. Kurmaev https://orcid.org/0000-0002-6462-
8230
Vyacheslav S. Bogdanov https://orcid.org/0000-0001-
9066-9020
Kasim F. Magomedov https://orcid.org/0000-0002-
ACKNOWLEDGMENTS
9847-4268
This work was financially supported by the Russian
Science Foundation (Project No. 16-13-10502). NMR and
elemental analyses were performed with the financial
support from Ministry of Science and Higher Education
of the Russian Federation using the equipment of Center
Elena S. Mikhaylik https://orcid.org/0000-0002-1869-
6101
Evgenii K. Golubev https://orcid.org/0000-0001-9184-
0467
Mikhail I. Buzin https://orcid.org/0000-0002-4390-5999

TUSKAEV ET AL.
15 of 16
[18] M. Schnitte, A. Staiger, L. A. Casper, S. Mecking, Nat.
Commun. 2019, 10, 2592. https://doi.org/10.1038/s41467-019-
10692-1
[19] S. C. Gagieva, V. A. Tuskaev, I. V. Fedyanin, M. I. Buzin, V. G.
Vasil'ev, G. G. Nikiforova, E. S. Afanas'ev, S. V. Zubkevich,
D. A. Kurmaev, N. A. Kolosov, E. S. Mikhaylik, E. K. Golubev,
A. I. Sizov, B. M. Bulychev, J. Organomet. Chem. 2017, 828, 89.
https://doi.org/10.1016/j.jorganchem.2016.11.026
Galina G. Nikiforova https://orcid.org/0000-0002-7713-
0415
Viktor G. Vasil'ev https://orcid.org/0000-0001-8667-
1750
Viktor N. Khrustalev https://orcid.org/0000-0001-8806-
2975
Pavel V. Dorovatovskii https://orcid.org/0000-0002-
[20] V. A. Tuskaev, S. C. Gagieva, D. A. Kurmaev, V. N.
Khrustalev, P. V. Dorovatovskii, E. S. Mikhaylik, E. K.
Golubev, M. I. Buzin, S. V. Zubkevich, G. G. Nikiforova, V. G.
Vasil'ev, B. M. Bulychev, K. F. Magomedov, J. Organomet.
Chem. 2018, 877, 85. https://doi.org/10.1016/j.jorganchem.
2018.09.014
[21] V. A. Tuskaev, S. C. Gagieva, D. A. Kurmaev, E. K. Melnikova,
S. V. Zubkevich, M. I. Buzin, G. G. Nikiforova, V. G. Vasil'ev,
D. Saracheno, V. S. Bogdanov, V. I. Privalov, B. M. Bulychev,
Appl. Organomet. Chem. 2020; Online Version of Record
before inclusion in an issue, e5933. https://doi.org/10.1002/
aoc.5933
2978-3614
Artem V. Bakirov https://orcid.org/0000-0003-0798-
2791
Maksim А. Shcherbina https://orcid.org/0000-0002-
5569-958X
Pavel B. Dzhevakov https://orcid.org/0000-0001-9319-
2950
Boris M. Bulychev https://orcid.org/0000-0003-3999-
3137
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How to cite this article: Tuskaev VA,
Gagieva SC, Kurmaev DA, et al. Novel titanium
(IV) diolate complexes with additional O-donor as
precatalyst for the synthesis of ultrahigh molecular
weight polyethylene with reduced entanglement
density: Influence of polymerization conditions
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