Kinetic and thermal study of ethylene-propylene copolymerization catalyzed by ansa-zirconocene activated with Alkylaluminium/borate: Effects of linear and branched alkylaluminium compounds as cocatalyst

Ali, Amjad; Jamil, Muhammad Imran; Uddin, Azim; Hussain, Munir; Aziz, T.; Tufail, Muhammad Khurram; Guo, Yintian; Jiang, Baiyu; Fan, Zhiqiang; Guo, Li

doi:10.1007/s10965-021-02525-x

Cited by 14 publications

(21 citation statements)

References 52 publications

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“…There are multiple steps in rac -Me 2 Si(2-Me-4-Ph-Ind)2ZrCl2/[Ph 3 C][B(C 6 F 5 ) 4 ], rac Et(Ind) 2 ZrCl 2 /[Ph 3 C][B(C 6 F 5 ) 4 ]-catalyzed olefin polymerization: initiation into a metal alkyl (M-R) bond, propagation through the resulting inserts, and chain transfer following either 2,1 or 1,2-α-olefin inserts. This has been demonstrated in previous studies [ 26 , 29 ]. Catalyst inactivity or dormancy, death, and other improbable outcomes are possible extra phases [ 7 , 25 ].…”

Section: Introductionsupporting

confidence: 87%

“…Metallocene catalysts combined with MAO, MMAO, and TIBA cocatalyst have recently been shown to be useful polymeric catalysts in the homopolymerization of ethylene and their co-/ter- polymerization with α-olefins and cyclic olefins [ 29 , 31 ]. The co- and ter- polymerization of E with P and bicyclic (N.B., ENB, and VNB) olefins have been investigated using certainly known metallocene catalysts in the literature [ 9 , 12 ].…”

Section: Resultsmentioning

confidence: 99%

“…Following a quick examination of the reaction conditions, it was determined that the most effective results were achieved at 50 °C and an Al/Zr ratio of 800. Earlier research exposed that the catalyst rac -Me 2 Et(Ind) 2 ZrCl 2 with ethylene bridges had the highest ethylene homo- and E/P copolymerization activity [ 7 , 25 , 29 ]. TIBA immediately activated the rac -Me2Et(Ind)2ZrCl2/borate and the copolymerization occurred at considerable rates, providing strong ethylene/VCH copolymerization activity in the beginning.…”

Section: Resultsmentioning

confidence: 99%

“…In that case, the average propagation rate constant value at 240 s polymerization time will be just 73% at 120 s polymerization time, suggesting no diffusion barrier in the system. In a previous study, we investigated the polyethylene and polypropylene homo- and ethylene/propylene copolymerization propagation rate constant under identical polymerization conditions and compared it to the E/VCH propagation rate constant; at 120 s, the k p PE, k p PP, k k p P E, k p P P, k p E, and k p VCH values are 4170, 250, 176, 21.53, 4266, 6410 and 93.6 L/mol·s, respectively [ 26 , 29 , 31 ], and the recommended moderate diffusion barriers are close to the real propagation rate constant in the early stages ( Figure 8 ). In addition, the initial k p PE and k p E values of E homo- and E/VCH copolymerization are slightly different (4170 and 6410).…”

Section: Resultsmentioning

confidence: 99%

“…In making the comparison with the quench-labeled pure samples, which already had S concentrations ranging from 5 to 20 ppm, the S content in a blank E/VCH sample produced under typical conditions but without the quenching step was approximately 0 ppm (see Scheme 1 ) [ 29 , 33 ]. A mechanistic model was proposed to explain the observed phenomena in detail.…”

Section: Characterizationsmentioning

confidence: 99%

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Methods for Predicting Ethylene/Cyclic Olefin Copolymerization Rates Promoted by Single-Site Metallocene: Kinetics Is the Key

et al. 2022

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In toluene at 50 °C, the vinyl addition polymerization of 4-vinyl-cyclohexene (VCH) comonomers with ethylene is investigated using symmetrical metallocene (rac-Et(Ind)2ZrCl2) combined with borate/TIBA. To demonstrate the polymerizations’ living character, cyclic VCH with linear-exocyclicπ and endocyclicπ bonds produces monomodal polymers, but the dispersity (Ɖ) was broader. The copolymers obtained can be dissolved in conventional organic solvent and have excellent thermal stability and crystalline temperature (ΔHm), and their melting temperature (Tm) varies from 109 to 126 °C, and ΔHm ranges from 80 to 128 (J/g). Secondly, the distribution of polymeric catalysts engaged in polymer chain synthesis and the nature of the dormant state are two of the most essential yet fundamentally unknown aspects. Comprehensive and exhaustive kinetics of E/VCH have shown numerous different kinetic aspects that are interpreted as manifestations of polymeric catalysts or of the instability of several types of active center [Zr]/[C*] fluctuations and formation rates of chain propagation RpE, RpVCH, and propagation rate constants kpE and kpVCH, the quantitative relationship between RpE, RpVCH and kpE, kpVCH and catalyst structures, their constituent polymer Mw, and their reactivity response to the endocyclic and exocyclic bonds of VCH. The kinetic parameters RpE, RpVCH, kpE, and kpVCH, which are the apparent rates for the metallocene-catalyzed E/VCH, RpE, and kpE values, are much more significant than RpVCH and kpVCH at 120 s, RpE and RpVCH 39.63 and 0.78, and the kpE and kpVCH values are 6461 and 93 L/mol·s, respectively, and minor diffusion barriers are recommended in the early stages. Compared with previously reported PE, RpE and kpE values are 34.2 and 7080 L/mol·s. VCH increases the RpE in the initial stage, as we are expecting; this means that the exocyclic bond of VCH is more active at the initial level, and that the chain transfer reaction of cyclic internal π double is increased with the reaction time. The tp versus Rp, kp, and [Zr]/[C*] fraction count may be fitted to a model that invokes deactivation of growing polymer chains. At tp 120–360 s higher, the incorporation rate of VCH suppresses E insertion, resulting in reduced molecular weight.

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Section: Introductionsupporting

confidence: 87%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Characterizationsmentioning

confidence: 99%

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Methods for Predicting Ethylene/Cyclic Olefin Copolymerization Rates Promoted by Single-Site Metallocene: Kinetics Is the Key

et al. 2022

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Thermal behaviour and crystallization analysis of ethylene‐propylene (EP) copolymer and EP‐styrene terpolymer

et al. 2023

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Polyolefin copolymers have been an important commercial product since their invention. Hence, it is crucial to study their co‐ and terpolymers due to their extensive use. In this paper, in situ synthesis of ethylene‐propylene (EP) copolymer, its terpolymer with styrene, and composites with nickel‐chromium (NiCr) layered double hydroxide (LDH) has been reported along with their thermal properties. Styrene had a significant impact on the activity, increasing the yield by 195% and 235% with an addition of 0.5 and 1.0 mL styrene, respectively, compared to neat EP. The crystallinity, melting temperature, and thermal stability decreased due to styrene; nevertheless, it performed better compared to a similar work of terpolymer where α‐olefin was the third monomer. The incorporation of NiCr LDH as a drop‐in filler during in situ polymerization affected adversely the thermal stability of the terpolymer. However, the ultrasonication treatment improved the thermal stability of the final product.

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Enhancing Metallocene Catalyst Activity: Utilizing Layered Double Hydroxide for Ethylene–Propylene Copolymerization

Mazhar,

Shehzad,

Hong

et al. 2023

Macro Materials & Eng

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This study reports the heterogenization of metallocene catalysts on sodium dodecyl sulfate (DDS)‐modified layered double hydroxides (LDHs) for efficient ethylene–propylene (EP) slurry‐phase copolymerization. The LDH support offers considerable compositional tunability. NiFe LDHs with different anions () and metallic compositions are applied as support for the metallocene catalysts; these significantly influence the catalytic properties of the heterogenized catalyst system. The supported‐catalyst intercalating DDS− anion in the galleries of NiFe and ZnAl LDHs demonstrates a high catalytic activity. They produce EP copolymers with high molecular weights (Mw) and wide polydispersity, compared with the homogeneous Zr catalyst. Further, the supported catalyst complex containing anion produces EP with a tenfold high Mw and demonstrate subdued catalytic activity. The higher basicity of the support is associated with the enhanced activity and the wider polydispersity of the EP pertaining to the different interactions of the catalyst molecule with the support. Overall, Ni‐containing LDH favors a higher activity, whereas Fe‐containing LDH favors a higher Mw. Therefore, NiFe‐based LDH results in both higher activity and molecular weight. 13C and 27Al magnetic angle spinning solid‐state nuclear magnetic resonance confirm the formation of the supported catalyst complex.

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Kinetic and thermal study of ethylene-propylene copolymerization catalyzed by ansa-zirconocene activated with Alkylaluminium/borate: Effects of linear and branched alkylaluminium compounds as cocatalyst

Cited by 14 publications

References 52 publications

Methods for Predicting Ethylene/Cyclic Olefin Copolymerization Rates Promoted by Single-Site Metallocene: Kinetics Is the Key

Methods for Predicting Ethylene/Cyclic Olefin Copolymerization Rates Promoted by Single-Site Metallocene: Kinetics Is the Key

Thermal behaviour and crystallization analysis of ethylene‐propylene (EP) copolymer and EP‐styrene terpolymer

Enhancing Metallocene Catalyst Activity: Utilizing Layered Double Hydroxide for Ethylene–Propylene Copolymerization

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