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Ali A, Naveed A, Shehzad K, Aziz T, Rasheed T, Moradian JM, Hassan M, Rahman A, Zhiqiang F, Guo L. Polymerization kinetics of bicyclic olefins and mechanism with symmetrical ansa-metallocene catalysts associated with active center count: relationship between their activities and structure and activation path. RSC Adv 2022; 12:15284-15295. [PMID: 35693231 PMCID: PMC9118019 DOI: 10.1039/d2ra01264b] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/02/2022] [Indexed: 12/30/2022] Open
Abstract
Copolymerization of ethylene (E) with 5-vinyl-2-norbornene (VNB) catalyzed by ansa-metallocenes allows the precise control of essential polymeric properties such as comonomer incorporation, molecular weight (M w), and polydispersity (Đ). Significant efforts have been devoted to synthesizing and developing novel catalysts, cocatalysts, and activators, although the fundamental elements of catalytic processes remain unclear. For example, it is questionable how polymeric catalysts are divided across dormant and active sites and how this distribution affects the order of monomers for the propagation rate, which widely vary in the literature. Furthermore, although the empirical correlation between the monomers and average M w has been established in many systems, the fundamental processes of chain termination remain unknown. Furthermore, the involvement of ion-pairing in metallocene-catalyzed polymerization and the termination mechanisms are also contentious issues. In this study, we describe the use of a quenched-labeling technique based on acyl chloride to selectively quench the zirconium metal-polymeric bond, which can be used to study the kinetics, active site [Zr][C*] counting, copolymer microstructure, and molecular weight distribution (MWD) to determine the rate laws for chain initiation, chain propagation rate (R p), propagation rate constant (k p) and chain termination. In addition, we also predict previously unknown chemical characteristics of E/bicyclic copolymerization processes, where either a cis-endocyclic double bond with steric properties or a vinyl exocyclic double bond affects the activity, i.e., [Zr]/[*C], (R p) and (k p). All these properties require the implementation of a particular kinetic mechanism that assumes the low activity of the building copolymer chains incorporating a single ethylene/VNB unit, i.e., the Cp2Zr-C2H5 group, in the ethylene addition process in the Cp2Zr-C bond. Due to β-agostic stabilization, the Cp2Zr-C2H5 group exhibits a distinct feature. These effects were confirmed experimentally, such as the E/VNB co-polymer activity and VNB mol%, propagation rate decrease in the polymerization time (t p) of 120 s to 1800 s, crystalline properties, and significant increase in molecular weight. The active center [Zr]/[*C] fraction considerably increased in the initial (t p) 840 s, and subsequently tended to the steady stage of 33%, which is lower than previously reported E homo- and E/P copolymerization. The lower [C*]/[Zr] in both the early and stable stages, decrease in VNB mol%, and R p with t p can be associated with the more significant fraction of Cp2Zr-CH2CH3-type dormant site by the β-agostic hydrogen interaction with the Cp2Zr metal. The t p versus R pE, R pVNB, k pE, k pVNB, and [Zr]/[C*] count could be fitted to a model that invokes deactivation of the growing polymer chains. In the case of the thermal behavior of the copolymers (melting temperature (T m) and crystalline temperature (ΔH m)), T m varied from 101 °C to 121 °C, while ΔH m varied from 9 to 16 (J g-1).
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Affiliation(s)
- Amjad Ali
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University Zhenjiang 212013 P. R. China
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University Hangzhou 310027 P. R. China
| | - Ahmad Naveed
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University Zhenjiang 212013 P. R. China
| | - Khurram Shehzad
- School of Micro-Nano Electronics, Hangzhou Global Scientific and Technological Innovation Center (HIC), Zhejiang University Xiaoshan 311200 China
- State Key Laboratory of Silicon Materials, Zhejiang University Hangzhou 310027 China
- ZJU-UIUC Joint Institute, Zhejiang University Jiaxing 314400 China
| | - Tariq Aziz
- Westlake University, School of Engineering Yunqi Campus Hangzhou Zhejiang 310024 PR China
| | - Tahir Rasheed
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum and Minerals (KFUPM) Dhahran 31261 Saudi Arabia
| | | | - Mobashar Hassan
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University Zhenjiang 212013 P. R. China
| | - Abdul Rahman
- School of Micro-Nano Electronics, Hangzhou Global Scientific and Technological Innovation Center (HIC), Zhejiang University Xiaoshan 311200 China
- Stoddart Institute of Molecular Science, Department of Chemistry, Zhejiang University Hangzhou 310027 China
| | - Fan Zhiqiang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University Hangzhou 310027 P. R. China
| | - Li Guo
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University Zhenjiang 212013 P. R. China
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Ali A, Naveed A, Rasheed T, Aziz T, Imran M, Zhang ZK, Ullah MW, Kubar AA, Rehman AU, Fan Z, Guo L. Methods for Predicting Ethylene/Cyclic Olefin Copolymerization Rates Promoted by Single-Site Metallocene: Kinetics Is the Key. Polymers (Basel) 2022; 14:459. [PMID: 35160449 PMCID: PMC8839136 DOI: 10.3390/polym14030459] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
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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Affiliation(s)
- Amjad Ali
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China; (A.A.); (A.N.)
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Z.-K.Z.); (Z.F.)
| | - Ahmad Naveed
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China; (A.A.); (A.N.)
| | - Tahir Rasheed
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Tariq Aziz
- School of Engineering Yunqi Campus, Westlake University, Hangzhou 310024, China;
| | - Muhammad Imran
- Department of Chemistry, Government College University, Lahore 54000, Pakistan; (M.I.); (A.U.R.)
| | - Ze-Kun Zhang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Z.-K.Z.); (Z.F.)
| | - Muhammad Wajid Ullah
- Biofuels Institute, School of Environment and Safety Engineering, Jiangsu University, Zhenjiang 212013, China;
| | - Ameer Ali Kubar
- State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China;
| | - Aziz Ur Rehman
- Department of Chemistry, Government College University, Lahore 54000, Pakistan; (M.I.); (A.U.R.)
| | - Zhiqiang Fan
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China; (Z.-K.Z.); (Z.F.)
| | - Li Guo
- Research School of Polymeric Materials, School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China; (A.A.); (A.N.)
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Dong J, Yang D, Wang B. Homo‐ and Copolymerization of Norbornene with Allyl Palladium and Nickel Complexes Bearing Imidazo[1,5‐a]pyridine Sulfonate Ligands. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jie Dong
- State Key Laboratory of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 PR China
| | - Dandan Yang
- State Key Laboratory of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 PR China
| | - Baiquan Wang
- State Key Laboratory of Elemento-Organic Chemistry College of Chemistry Nankai University Tianjin 300071 PR China
- State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 PR China
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Ali A, Nadeem M, Lu J, Moradian JM, Rasheed T, Aziz T, Maouche C, Guo Y, Awais M, Zhiqiang F, Quo L. Rapid kinetic evaluation of homogeneous single-site metallocene catalysts and cyclic diene: how do the catalytic activity, molecular weight, and diene incorporation rate of olefins affect each other? RSC Adv 2021; 11:31817-31826. [PMID: 35496867 PMCID: PMC9041555 DOI: 10.1039/d1ra06243c] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/11/2021] [Accepted: 09/09/2021] [Indexed: 01/02/2023] Open
Abstract
The kinetics and mechanism of ethylene and cyclic diene 5-ethylidene-2-norbornene (ENB) copolymerization catalyzed by rac-Et(Ind)2ZrCl2/[Ph3C][B(C6F5)4]/triisobutylaluminium (TIBA) were investigated using a quench-labeling procedure using 2-thiophenecarbonyl chloride (TPCC). The E/ENB copolymers were characterized by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and 1H nuclear magnetic resonance (NMR) spectroscopy and sulfur analysis. To reduce the errors of the ethylene-diene copolymerization for the kinetics study, we selected E/ENB with steric and electronic features that permit us to elucidate the metallocene catalyst behavior against dienes. A quantitative approach of catalyst speciation, stereodynamics, and micro-kinetics assisted the resolution of mechanistic problems, such as the elastomeric synthesis of ethylene propylene diene monomer rubber (EPDM), the catalyst resting state nature, and how much ion-pairing occurs during polymerization. We report here the precise observation of metal-polymer species, explanation of the dynamics of their initiation, propagation, and termination, and ethylene ENB copolymer development. An approach based on acyl chloride was used to selectively quenched transition metal-polymer bonds to evaluate the polymeric catalyst in terms of its reaction rate, R p, propagation rate content, k p, and mole fraction of active centers. It is noted that the decline in catalytic activity in the range of 1800 s, and the active center [Zr]/[*C] fraction significantly increased during the initial 1000 s and then tended towards a steady figure of 86%. It is suggested that nearly complete initiation of all olefins catalysts can be obtained after a sufficiently extended reaction. The quick increase in active sites in the first stage can be described by the immediate initiation of active sites positioned on the surfaces of catalyst particles. The initial polymerization rate, R p, is high and the crystalline properties of the E/ENB copolymer are low due to the greater incorporation of ENB in the polymer backbone, and later the polymerization reaction rates remained stable with a lower mol% of ENB. The melting temperature (T m) ranges from 108 to 127 °C, whereas the crystalline temperature ranges from 63 to 108 (J g-1). In the E-ENB copolymers, the value of k pE is much greater than that of k pENB; at 120 s, the k pE and k pENB values are 9115 and 431 L mol-1 s-1, respectively, implying smaller diffusion barriers in the early stages, which are close to the actual propagation rate constant.
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Affiliation(s)
- Amjad Ali
- Research School of Polymeric Materials Science & Engineering, Jiangsu University Zhenjiang 212013 PR China
| | - Muhammad Nadeem
- Department of Environmental Engineering, Wuhang University of Technology Wuhan 430223 PR China
| | - Jinwei Lu
- Research School of Polymeric Materials Science & Engineering, Jiangsu University Zhenjiang 212013 PR China
| | - Jamile Mohammadi Moradian
- Research School of Polymeric Materials Science & Engineering, Jiangsu University Zhenjiang 212013 PR China
| | - Tahir Rasheed
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia
| | - Tariq Aziz
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia
| | - Chanez Maouche
- Research School of Polymeric Materials Science & Engineering, Jiangsu University Zhenjiang 212013 PR China
| | - Yintian Guo
- Interdisciplinary Research Center for Advanced Materials, King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia
| | - Muhammad Awais
- Research Center of Fluid Machinery Engineering and Technology, Jiangsu University Zhenjiang 212013 PR China
| | - Fan Zhiqiang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University Hangzhou 310027 PR China
| | - Li Quo
- Research School of Polymeric Materials Science & Engineering, Jiangsu University Zhenjiang 212013 PR China
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Dong J, Wang B. Homo- and copolymerization of norbornene using tridentate IzQO palladium catalysts with dimethylaminoethyl as a side arm. Polym Chem 2021. [DOI: 10.1039/d1py00699a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rigid IzQO–Pd catalysts were synthesized by Rh(iii)-catalyzed C–H/alkyne annulation and applied for the homo- and copolymerizations of norbornene with polar vinyl monomers.
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Affiliation(s)
- Jie Dong
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, PR China
| | - Baiquan Wang
- State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, PR China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, PR China
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Chowdhury SI, Tanaka R, Nakayama Y, Shiono T. Synthesis of norbornene/divinylbenzene copolymers catalyzed by anilinonaphthoquinone‐ligated nickel complexes and their applications for the synthesis of graft polymers. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20200133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
| | - Ryo Tanaka
- Graduate School of Engineering Hiroshima University Hiroshima Japan
| | - Yuushou Nakayama
- Graduate School of Engineering Hiroshima University Hiroshima Japan
| | - Takeshi Shiono
- Graduate School of Engineering Hiroshima University Hiroshima Japan
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