CC BY
26
UDC 678.13
A. V. Chapurina, P. M. Nedorezova, A. N. Klyamkina,
A. M. Aladyshev, B. F. Shklyaruk, T. V. Monachova, G. E. Zaikov
PROPYLENE/1-BUTENE AND PROPYLENE/1-PENTENE COPOLYMERS.
SYNTHESIS AND PROPERTIES
Keywords: copolymerization, propylene, 1-butene, 1-pentene, metallocene catalyst, copolymer properties, thermooxidation.
Propylene - 1-butene and propylene - 1-pentene copolymerization at 60°C in the propylene bulk with the homogeneous isospecific metallocene catalyst of the C2 symmetry rac-Me2Si(4-Ph-2-MeInd)2ZrCl2 activated by methylaluminoxane is studied. Thermal, mechanical characteristics and thermooxidation stability have been investigated.
Ключевые слова: сополимеризация, пропилен, 1-бутен, 1-пентен, металлоценовый катализатор, свойства сополимеров, термоокисление.
Исследована сополимеризация пропилен-1-бутена и пропилен-1-пентена при 60°С в массе пропилена с гомогенным изоспецифическим металлоценовым катализатором С2-симметрии рац-Me^Si (4-Ph-2-MeInd)2ZrCl2, активированного метилалюмоксаном. Исследованы тепловые, механические характеристики и термоокислительная стабильность.
Polypropylene is one of the most important polymeric materials and is rated next to PE with respect to worldwide consumption [1]. The search for new ways to modify the PP characteristics and to broaden its application areas has been in progress for many years. In this direction, special attention has been placed on the effective catalysts providing intensification of industrial processes for the production of different materials on the polypropylene base, including the propylene copol-ymers.
Efficient homogeneous systems based on metallocene complexes of group IVB elements opened new possibilities for production of new materials based on homo- and copolymers of a-olefins [1-4]. One of the methods for modifying the properties of isotactic PP consists in the copolymerization of propylene with various olefins: linear, branched, and cyclic [5-10]. Owing to the uniformity of active centers, metallocene catalysts allow the synthesis of polymers with a narrow molecular-mass distribution and compositionally homogeneous copolymers.
In the case of metallocene catalysts, the differences in the reactivities of ethylene, propylene, higher a-olefins, and a number of other monomers are much smaller, than those for traditional catalytic systems based on compounds of titanium or vanadium. This fact ensures the synthesis of polymers with a large amount of branches which cannot be prepared with the above-mentioned traditional catalysts. Most properties depend on the type and concentration of a comonomer.
The copolymerization of PP is usually performed with the use of linear olefins containing an even number of carbon atoms in a molecule (ethylene, 1-butene, 1-hexene, and 1-octene) [8, 10, 11]. As it was shown in [7, 12-15], the degree of comonomer insertion exerts a stronger effect on the properties of copolymers than does the comonomer size.
The first data on the copolymerization of pro-pylene with 1-pentene were published in 1996, and they were immediately used in industry [16]. Later, a number of studies on the effect of other comonomers with an odd number of carbon atoms (1-heptene, 1-nonene) on the behavior of PP appeared [17, 18]. As was shown in
[17, 18], these comonomers may modify PP properties efficiently.
In this study, we examined the copolymeriza-tion of propylene with 1-butene and 1-pentene in liquid propylene medium in the presence of a highly active isospecific homogeneous ansa-metallocene catalyst with the C2-symmetry, rac-Me2Si(4-Ph-2-MeInd)2ZrCl2, activated by methylaluminoxane (MAO). The effects of the type of comonomer on the rate of copolymerization and the molecular-mass characteristics, microstructure, thermophysical and mechanical properties of the copolymers are investigated. The results of this study are compared with the data obtained with the same system used for the copolymerization of propylene with ethylene, 1-hexene, and 1-octene [1921].
Experimental Part
The structure of rac-Me2Si(4-Ph-2-Melnd)2ZrCI2 (MC) (Boulder Co.) is outlined below.
MAO (Witco) was used as a 10% solution in
toluene.
Propylene of the polymerization-purity grade was used as received.1-Butene contained 98 vol % of the basic compound.1-Pentene (Aldrich) was distilled over sodium in a flow of argon.
The homopolymerization of propylene was performed in a setup equipped with autoclave reactors with a volume of 0.2 or 0.4 l under the regime of complete filling of the system with liquid monomer [4]. Before experiments, the setup was evacuated for 1 h at 60°C. For the copolymerization of propylene with 1-butene and 1-pentene, two-thirds of the reactor volume was filled with liquid propylene, the necessary amount of the comonomer was charged with a syringe, and the amount of propylene necessary for full filling of the reactor was fed.
When MAO was loaded, a solution of metallocene in MAO was charged at the temperature of polymerization.
The microstructure of PP and propylene-based copolymers were determined via IR and 13C NMR spectroscopy. The 13NMR spectra of 5% copolymer solutions in o-dichlorobenzene were measured at 120°C on a Bruker DPX-2500 instrument operating at a frequency of 162.895 MHz.
The stereoregularity parameters were estimated from the intensity ratio of absorption bands at 998 and 973 cm1, D998/D973 (macrotacticity). This parameter characterizes the fraction of propylene links in isotactic sequences with a length of 11- 13 monomer units [22]. The content of 1-butene was estimated from the ratio of bands at 760 and 1460 cm-1; the content of 1-pentene, from the band at 740 cm-1 [18].
The molecular-mass characteristics of PP and copolymers were determined at 135°C in o-dichlorobenzene on a Waters 150-C gel chromatograph equipped with a linear HT-^-styragel column. The average molecular mass was calculated from the universal calibration curve plotted relative to PS standards.
X-ray studies were conducted on a DRON-3M diffractometer operated in the transmission mode with the use of Cu^tt radiation. The diffractometric measurements were performed with an asymmetric quartz monochromator focusing on the primary X-ray beam. The diffraction picture was scanned in the range of diffraction angles 20 = 6°-36° at a scan step of 20 = 0.04° and an accumulation time of t = 10 s. Degree of crystallinity K was measured with the use of X-ray amorphous PP. The error in the X-ray diffraction measurements of K did not exceed ±5%.
The thermophysical characteristics of polymer samples (the temperatures and enthalpies of melting and crystallization) were measured on a DSK-30 calorimeter equipped with a TC-15 processor and Mettler STAR SW 8.00 software. Measurements were performed at a rate of 10 K/min in an atmosphere of nitrogen in the heating-cooling- heating mode. The enthalpy of melting of PP with a degree of crystallinity of 100%, AH°m was assumed to be 167 J/g [23].
Samples used for mechanical testing were prepared via molding at a temperature of 190°C and a pressure of 150 atm. The pressurized samples were cooled to room temperature at a rate of 20 K/min. Irganox-1010 (~0.8 wt %) was added to stabilize the nascent polymer. Tensile tests of the polymers were performed at a rate of 50 mm/min on an Instron 1122 tensile machine using trowel-shaped samples with a cross-sectional area of 0.75 mm 0.5 x 5.0 mm and a base length of 35 mm.
The thermal oxidation of the of propylene co-polymers was studied in the kinetic regime at 30°C and an oxygen pressure of 300 Torr [24]. The kinetics of oxygen uptake was investigated on a high sensitivity manometric installation. The absorber of volatile products was solid KOH.
Results and Discussion
Synthesis of Propylene Copolymers with Higher Olefins
Table 1 lists the data on the copolymerization of propylene with 1-butene and 1-pentene in liquid propylene medium. It is seen that different initial concentra-
tions of the MC catalyst significantly affect the activity of the MC-MAO catalytic system (experiments 1, 8). A decrease in the concentration of the MC-based complex during its formation, as was shown in [25], brings about an increase in the activity of the catalytic system by a factor of nearly 2 from 240 kg PP/(mol Zr h) (experiment 1) to 440 kg PP/(mol Zr h) (experiment 8).
Table 1 - Copolymerization of propylene with 1-butene and 1-pentene in the propylene bulk (rac-Me2Si(4-Ph-2-MeInd)2ZrCl2-catalyst), Tm=60oC, and a reactor volume of 0.2 l). Note: * In experiments 1-7, at the stage of catalytic system formation, Al:Zr= 500 (mol/mol); in experiments 8-13, Al:Zr=1200 (mol/mol). ** The reactor volume is 0.4 l
MC x Molar Comon Time of
10-7, ratio omer polymer
a •Й mol (A1:Zr) x 10-3 contenti n the ization, min g T3
a X w mono- <D £
mer mixture, mol %
1- Butene*
1 1.9 18.0 0 11 8.2
2 2.1 16.0 1.0 10 8.0
3 2.6 13.0 1.8 8 14.5
4 2.3 13.0 3.4 10 40.0
5 2.3 13.0 7.2 17 11.2
6 4.4 11.0 20.5 35 10.5
7 7.1 10.0 34.1 40 12.5
1- Pentene*
8 1.0 35.0 0** 30 23.0
9 1.7 18.6 0 7** 20 24.0
10 1.2 31.0 1.4 20 30.0
11 6.0 10.0 2 3** 17 19.0
12 5.3 10.0 5.5 20 10.0
13 8.0 9.7 12.5 35 19.0
Akti Content 2998 Mw x Mw
t vity, of D973 10-3 Mn
i kg comon
•c <D Ро1У omer in
A X w mer/ copol-
(mmol Zr h) ymer, mol %
1- Butene*
1 240 0 0.87 800 2.0
2 220 0.5 0.87 820 2.2
3 408 0.9 0.85 430 2.3
4 1012 1.8 0.84 210 2.5
5 170 5.3 0.77 300 2.2
6 41 19.5 0.56 240 2.1
7 26 30 0.54 160 2.2
1- Pentene*
8 440 0 0.87 720 2.0
9 410 0.3 0.87 850 2.3
10 714 1.2 0.82 460 2.0
11 112 1.5 0.76 480 2.1
12 57 5.2 0.70 350 1.9
13 41 10.2 0.55 340 2.9
Addition of the comonomers influences the ac-
tivity and molecular mass of the polymers. Thus, even at small contents of 1-butene (below 3.4 mol %) and 1-pentene (below 1.4 mol %) in the monomer mixture, the activity of the catalytic system increases appreciably. In the case of copolymerization with 1-butene, the yield of the copolymer increases by a factor of 2-3 relative to that for the homopolymerization of propylene; for copolymerization with 1-pentene, the yield of the copolymer increases by a factor of 1.5. A further increase in the concentration of these comonomers decreases the rate of polymerization. The activation effect of small additives of less reactive comonomers is referred to as the comonomer effect [8, 25-29].
As it is seen from Table 1, the molecular mass of the propylene-1-pentene and propylene - 1-butene copolymers first slightly increases when small amounts of the comonomer are added, but after a further increase in the content of comonomers, molecular mass decreases. The same character of a change in molecular mass was observed for the copolymerization of propylene with 1-hexene and 1-octene [20, 21]. An increase in molecular mass at a small content of the comonomer on a sterically hindered active center [30, 31] may be explained by a decline in the rate of chain transfer to the comonomer. A further reduction in molecular mass during copolymerization is evidently associated with an increase in the rate of chain termination on the comonomer.
Figure 1 shows the 13C NMR spectra of the propylene-1-butene and propylene-1-pentene copolymers containing 5.3 and 5.2 mol % comonomers, respectively.
00
5
: 7 ID 10 7 7
(ppm) (b)
Fig. 1 - NMR spectrum of propylene-1-butene (a) and propylene-1-pentene (b) copolymers containing 5.3 and 5.2 mol % comonomer units, respectively
As it can be seen, polymer chains are mostly composed of isotactic pentads; as well as for homopolymer i.e., the character of stereoregulation
slightly changes during polymerization.
The incorporation of even small amounts of the comonomers causes a reduction in stereoregularity parameters, which are calculated from the IR spectra (Table 1). At close contents of the comonomers, a more distinct reduction in regularity is observed for propyl-ene-1-pentene copolymers. In accordance with [32], during the copolymerization of 1-pentene with propylene on the isospecific sterically hindered ansa-metallocene Me2Si(2-Me-Ind)2ZrCl2, the catalyst becomes even aspecific at a high content of 1-pentene. It was assumed that the steric control of the active center depends on the type and content of comonomers.
Reactivity Ratios
On the basis of 13C NMR and IR data, reactivity ratios of propylene and comonomers were determined, as described in [33, 34]. The values of reactivity ratios suggest the statistical distribution of comonomer units in copolymer chains.
According to the 13C NMR data, reactivity ratios for the copolymerization of propylene with 1-butene are: r1 = ГС3Н6 = 1.1, r2 = ГС4Н8 = 0.9, and rrr2 ~ 1.0; for the copolymerization of propylene with 1-pentene: r1 = rc 3Н6 = 1.06, r2 = rC5H10 = 0.94, and r1-r2 ~ 1.0. As was shown in [20, 21, 34], for the copolymerization of propylene with 1-hexene catalyzed by MC-MAO, rC3H6 =1 and rC6H12 =1; for propylene with 1-octene, ГсзН6 =1 and rC8H12 =1, r1-r2=1. The fact that, for the copolymerization of propylene with higher linear olefins in liquid propylene, the reactivity ratios are similar indicates the ideal (azeotropic) character of copolymerization. This circumstance makes it possible to easily control the composition of copolymers through variation in the ratio of comonomer concentrations in the reaction solution.
Figure 2 plots the copolymer composition against the composition of the comonomer mixture for the copolymerization of propylene with 1-butene, 1-pentene, 1-hexene, and 1-octene. The linear dependence is preserved throughout the studied composition range.
35
M,, mol%
Fig. 2 - Composition of the propylene- based copolymers vs. composition of the comonomer mixture for copolymerization with MC-MAO: (1) propylene-1-butene, (2) propylene-1-pentene, (3) propylene-1-hexene, and (4) propylene-1-octene. M1 and m2 are the contents of comonomers in the monomer mixture and copolymers, respectively
9 114 160 113
10 118 154 105
11 98 143 91
12 88 122 72
13 55 93 43
It is known that a medium has a marked effect on the reactivity of comonomers [35]. For copolymers synthesized in liquid propylene, relative to those synthesized in toluene [25], a smaller content of the comonomer in the monomer mixture is needed to incorporate the same amount of higher linear olefin into the polymer chain. The above values of reactivity ratios for the copolymerization of propylene with higher a-olefins, are distinctive features of the process in liquid propylene and are associated with the nature of active centers on sterically hindered isospecific MC catalysts [21].
Thermophysical Properties
Table 2 summarizes the thermophysical properties of propylene-1-butene and propylene-1-pentene co-polymers. It is clear that the incorporation of the comonomers into the polymer chain results in marked reductions in Tm, Tcr, and the enthalpies of melting and crystallization. Decreases in the temperature and enthalpy of melting are associated with the greater defectiveness of PP crystals at an increase of the comonomer content.
Table 2 - Thermophysical characteristics of propylene- 1-butene and propylene- 1-pentene copolymers (Tmi, AHmi, Tm2, AHm2 are the temperatures of melting and the enthalpies of melting during the first and second heating scans, respectively; Tcr and AHcr are the temperature of crystallization and the enthalpy of crystallization
Experiment Content of comonomer units in the copolymer,mol % Tmb oC AHmb J/g Degree of crystalli nity (DSC), %
Propy lene-1-butene
1 0 164 109 66
2 -0.5 161 117 71
3 0.9 157 105 64
4 1.8 154 100 61
5 5.3 141 90 55
6 19.5 107 73 44
7 30 - - 31
Propylene-1-pentene
8 0 166 135 73
9 0.3 162 128 72
10 1.2 155 128 65
11 -1.5 144 102 65
12 5.2 126 87 61
13 10.2 - - -
Experim et T oC AHcr; J/g Tm2j oC AHm2, J/g
Propy lene-1-butene
1 109 109 163 107
2 105 105 159 106
3 107 94 157 94
4 - - 154 106
5 - - 144 94
6 68 60 107 62
7 50 48 90 51
Propylene-1-pentene
8 114 163 121
Figure 3 shows the dependences of Tm values for propylene-1-butene and propylene-1-pentene copolymers on the content of comonomers. For comparison, the same figure shows the data obtained for propylene copolymers with ethylene, 1-hexene, and 1-octene [19-21]. The incorporation of 1-hexene and 1-octene into PP chains has a much more pronounced effect on the Tm of the copolymer than does the incorporation of ethylene, 1-butene and 1-pentene. If for propylene copolymers with 1-hexene and 1-octene, the dependences of Tm on the composition of copolymers are almost the same, then, for propylene copolymers with 1-butene or ethylene, a larger amount of the comonomer is needed to attain the same reduction in Tm. The copolymers of propylene with 1-pentene take an intermediate position between these two groups of the copolymers.
Fraction of comonomer in copolymer, mol%
Fig. 3 - Plot of Tm vs. the content of comonomer units in propylene- based copolymers synthesized with MC-MAO: (1) propylene-1-butene, (2) propylene-ethylene, (3) propylene- 1-pentene, (4) propylene-1-hexene, and (5) propylene- 1-octene
X-Ray Diffraction Study
Figure 4 demonstrates the diffractograms of propylene copolymers with 1-butene measured for nascent samples and films, which will be subsequently used for mechanical tests. It is seen that the diffractograms of nascent samples (in addition to reflections due to a-PP) show a reflection due to y-PP (20 ~ 20°). The content of y-PP increases as the content of the comonomer changes up to the certain value, and for the copolymers containing 1.8 and 5.3 mol % butene, the amounts of y-PP are ~5 and 10%, respectively (Fig. 4a, diffractograms 4, 5). With a further increase in the content of 1-butene the copolymer, the amount of y-PP begins to decrease and, at butene contents above 19.5 mol %, the samples undergo crystallization and a-PP is formed. The degree of crystallinity of nascent samples varies in the range from ~70% for the homopolymer (Fig. 4a, diffractogram 1) to ~45% for the copolymers containing 30 mol % 1-butene
(Fig. 4a, diffractogram 7). The degrees of crystallinity for all films are almost the same: ~55%. For copolymer films, the amount of y-PP is much smaller than that for nascent samples. Thus, the amount of y-PP for the copolymer containing 5.3 mol % 1-butene is as low as 3% (Fig. 4b, diffractogram 5).
(a)
A
A
A A I \
A I л
/•vj W^
I I\ f\
i^jKЛл '
& /1 A F \
" W\
16 24
diffraction angle 20° , deg
Fig. 4 - Diffractograms of propylene-1-butene copolymers for (a) nascent samples and (b) films: (1) aPP, (2-7) the contents of the comonomer are 0.5, 0.9, 1.8, 5.3, 19.5, and 30 mol %, respectively
The diffractograms of nascent copolymer samples clearly show that diffraction reflections shift to smaller diffraction angles. For statistical propylene-1-butene copolymers, this effect was repeatedly observed for various catalytic systems [36-40, 46]. This outcome may be explained by the fact that, even after replacement of a certain amount of propylene units with 1-butene units, copolymer macromolecules continue formation of the crystalline component of a-PP but have
other unit-cell parameters. In fact, in the case of isotac-tic PP, a macromolecule occurs in the conformation of the 3/1 helix with a cross-sectional area of 0.34 nm2 and an identity period of 0.65 nm for all polymorphic structures. Although isotactic polybutene exhibits the conformational type of polymorphism, it has polymorphic structure in which macromolecules assume the conformation of the 3/1 helix with a cross-sectional area of 0.44 nm2 and an identity period of 0.65 nm. Hence, it is expected that, in the copolymers, the unit-cell parameters for the monoclinic syngony of a-PP will increase; as a result, diffraction reflections shift to smaller diffraction angles.
Mechanical Properties
Table 3 lists the data on the degree of crystallinity of the copolymers (X-ray data) and the mechanical characteristics of propylene-1-butene and pro-pylene-1-pentene copolymers. Because of the isomorphism of
Table 3 - Mechanical properties of propylene-1-butene and propylene-1-pentene copolymers (E is the elastic modulus, ay is the yield point, ey is the tensile yield strain, ab is the breaking strength and eb is the elongation at break
Experiment Content of comonomer, mol% Degree of crystallinity (X-ray difraction), % E, MPa MPa
Propylene- butene
1 0 67 1570 40.3
2 -0.5 69 1545 39.5
3 0.9 71 1290 34.5
4 1.8 60 1470 37.3
5 5.3 62 1240 34.9
6 19.5 52 620 21.3
7 30 52 450 16.4
Propylene- pentene
8 0 73 1380 37.3
10 1.2 72 1200 35.9
11 -1.5 65 920 29.8
12 5.2 61 785 21.8
13 10.2 50 270 11.1
Experiment Sy, % MPa Sb, %
Propylene- butene
1 7.2 29.1 200
2 7.2 32.4 270
3 7.1 22.9 300
4 7.3 30.2 400
5 8.9 31.6 600
6 10.6 25.8 500
7 11.3 25.6 780
Propylene- pentene
8 7.1 29.8 220
10 7.5 37.7 550
11 7.8 30.5 440
12 9.5 30.6 460
13 12.0 30.8 590
propylene and 1-butene units in the crystal lattice [42, 43], the properties of propylene-1-butene copolymers differ appreciably from the corresponding characteristics of propylene copolymers with other olefins.
The crystallinity of propylene-1-butene copol-ymers changes to a much smaller extent with an increase in the amount of the comonomer relative to the copolymers of another type (propylene- ethylene, pro-pylene- hexene, propylene- octene). This tendency is consistent with the published data which shows that 1-butene slightly affects the crystallization of the isotactic PP owing to its cocrystallization with propylene in a wide range of copolymer compositions [44, 45]. The incorporation of 1-pentene entails a more efficient reduction in the degree of crystallinity than the incorporation of 1-butene. 1-pentene, like 1-butene, may undergo cocrystallization with propylene molecules in PP chains. At the same time, 1-hexene and 1-octene are incorporated into polymer chains in the form of lattice defects and thus, ensure disorder that causes more distinct decreases in Tm and crystallinity of polymers [21, 32].
As it is clear from Table 3 the incorporation of 1-butene and 1-pentene into the polypropylene chain leads to a reduction in the elastic modulus and tensile yield stress, an increase in tensile strength parameters, and improvement of the elastic behavior of the copoly-mers. Figure 5 presents the stress-strain curves for propy lene-1-butene and propylene-1-pentene copolymers. The incorporation of even small amounts of these comonomers into the chains of PP chains brings about appreciable modification.
□ 10 □ 200 30D JCQ 500 GOO
Strain, %
Fig . 5 - Stress- strain curves of (a) propylene-1-butene and (b) propylene-1-pentene copolymers synthesized with MC-MAO. The contents of 1-butene units in the copolymers are (1) 0.5, (2) 1.8, (3) 5.3, and (4) 19.5 mol %; the contents of 1-pentene units
in the copolymers are (1) 0, (2) 0.9, (3) 1.5, (4) 5.2, and (5) 10.2 mol %
Oxidation of copolymer polypropylene-1-pentene
Figure 6 shows the kinetic curves for the thermooxidation of propylene copolymers with 1-pentene. It is seen that the induction periods for all samples are close. At that time the reaction rate corresponding to the slope of the kinetic curves for samples copol-ymers with a low content of 1-pentene unit (0.3% and 1.5%) compared to the IPP slightly increases. Further increasing of the 1-pentene content in copolymers leads to decreasing of the thermooxidation reaction rate (Table 4).
Time, mi»
Fig. 6 - Oxygen absorption kinetic curves for the oxidation at 130°C of (1) IPP and copolymers pro-pylene-1-pentene (mol%): (2) 0.3, (3) 1.5, (4) 10.2
Apparently, a small increase of reaction rate for copolymers with a comonomer content 0.3 and 1.5 % is associated with disordered packing of the macromole-cules with the introduction of 1-pentene units in polymer chain. Further decline in the rate is determined by diffusion effects.
Thus, the modification of PP with even small amounts of higher olefins influences the regularity of polymer chains, affects the molecular-mass characteristics of the copolymers, causes marked changes in the thermal behavior, entails decreases in Tm and the degree of crystallinity, allows controlling the rigidity and elasticity of the resulting materials and influence on thermooxidation stability.
Table 4 - Thermoxidation properties propylene- pen-tene copolymers
Experi- Content of The parameter for the
ment pentene units oxidation of PP-pentene
in the copol- at 130°C
ymer, 104,
mol % molO2/kgPP sec
1 0 1.45
2 -0.5 2.24
3 1.5 2.00
4 5.2 1.13
5 10.25 0.40
This work is executed at financial backing by RFBR, grant 13-03-00948a.
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© A. V. Chapurina - Researcher of Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia, P. M. Nedorezova - Ph.D., Leading Researcher of Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia, A. N. Klyamkina - Researcher of Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia, A. M. Aladyshev - Ph.D., Head of The Catalysis of Polymerization Processes Laboratory, Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia, B. F. Shklyaruk - Ph.D., Senior Researcher of Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia, T. V. Monachova - Ph.D., Senior Researcher of Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, Russia, G. E. Zaikov - Doctor of Chemistry, Full Professor of Plastics Technology Department, Kazan National Research Technological University, Kazan, Russia, [email protected].
© А. В. Чапурина - науч. сотр. Института химической физики им. Н.Н. Семенова РАН, Москва, Россия, П. М. Недорезова -канд. хим. наук, вед. науч. сотр. того же ин-та, А.Н. Клямкина - науч. сотр. того же ин-та, А. М. Аладышев - канд. хим. наук, зав. лаб. катализа полимеризационных процессов же ин-та, Б. Ф. Шклярук - канд. хим. наук,, ст. науч. сотр. Института нефтехимического синтеза им. А.В. Топчиева РАН, Москва, Россия, Т. В. Монахова - канд. хим. наук, ст. науч. сотр. Института биохимической физики им. Н.М. Эмануэля, Москва, Россия, Г. Е. Заиков - д-р хим. наук, проф. каф. технологии пластических масс КНИТУ, [email protected].
