Polystyrene Chain Growth from Di-End-Functional Polyolefins for Polystyrene-Polyolefin-Polystyrene Block Copolymers

Kim, Chung Sol; Park, Seung Soo; Kim, Sung‐Dong; Kwon, Soo Hyun; Baek, Jun Won; Lee, Hyun Ju

doi:10.3390/polym9100481

Cited by 13 publications

(18 citation statements)

References 52 publications

(94 reference statements)

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“…Homo-PS was concomitantly generated at 27-29% the amount of the total consumed styrene. The numbers of PS chain-growing sites were calculated by dividing the weights of the total consumed styrene with the measured homo-PS M n values, which roughly agreed with the value of "2 × Zn (µmol)", indicating the growth of PS chains mainly from polyolefinyl groups in zincate species [ [33,34,52].…”

Section: Discussionmentioning

confidence: 62%

“…Syntheses of polyethylene-block-polyester and polyethylene-block-polyether have been attempted with POs functionalized with -OH end groups, which were generated by treatment of the CCTP product (polyolefinyl) 2 Zn with O 2 [28][29][30][31]. We also discovered a method to grow polystyrene (PS) chains initiating from (polyolefinyl) 2 Zn that allows the syntheses of commercially more relevant PO-block-PS and PS-block-PO-block-PS in one-pot [32][33][34][35]. In those works, n-BuLi•(TMEDA) (TMEDA = tetramethylethylenediamine, i.e., Me 2 NCH 2 CH 2 NMe 2 ) and Me 3 SiCH 2 Li•(PMDTA) (PMDTA = pentamethyldiethylenetriamine, i.e., Me 2 NCH 2 CH 2 N(Me)CH 2 CH 2 NMe 2 ) were introduced to grow PS chains from (polyolefinyl) 2 Zn.…”

Section: Methodsmentioning

confidence: 99%

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Polystyrene Chain Growth Initiated from Dialkylzinc for Synthesis of Polyolefin-Polystyrene Block Copolymers

et al. 2020

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Polyolefins (POs) are the most abundant polymers. However, synthesis of PO-based block copolymers has only rarely been achieved. We aimed to synthesize various PO-based block copolymers by coordinative chain transfer polymerization (CCTP) followed by anionic polymerization in one-pot via conversion of the CCTP product (polyolefinyl)2Zn to polyolefinyl-Li. The addition of 2 equiv t-BuLi to (1-octyl)2Zn (a model compound of (polyolefinyl)2Zn) and selective removal or decomposition of (tBu)2Zn by evacuation or heating at 130 °C afforded 1-octyl-Li. Attempts to convert (polyolefinyl)2Zn to polyolefinyl-Li were unsuccessful. However, polystyrene (PS) chains were efficiently grown from (polyolefinyl)2Zn; the addition of styrene monomers after treatment with t-BuLi and pentamethyldiethylenetriamine (PMDTA) in the presence of residual olefin monomers afforded PO-block-PSs. Organolithium species that might be generated in the pot of t-BuLi, PMDTA, and olefin monomers, i.e., [Me2NCH2CH2N(Me)CH2CH2N(Me)CH2Li, Me2NCH2CH2N(Me)Li·(PMDTA), pentylallyl-Li⋅(PMDTA)], as well as PhLi⋅(PMDTA), were screened as initiators to grow PS chains from (1-hexyl)2Zn, as well as from (polyolefinyl)2Zn. Pentylallyl-Li⋅(PMDTA) was the best initiator. The Mn values increased substantially after the styrene polymerization with some generation of homo-PSs (27–29%). The Mn values of the extracted homo-PS suggested that PS chains were grown mainly from polyolefinyl groups in [(polyolefinyl)2(pentylallyl)Zn]−[Li⋅(PMDTA)]+ formed by pentylallyl-Li⋅(PMDTA) acting onto (polyolefinyl)2Zn.

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Section: Discussionmentioning

confidence: 62%

Section: Methodsmentioning

confidence: 99%

Polystyrene Chain Growth Initiated from Dialkylzinc for Synthesis of Polyolefin-Polystyrene Block Copolymers

et al. 2020

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“…Hf-C naphthyl , Hf-N amido , and Hf-N pyridine distances were almost unaffected by the substituents, being 2. 25…”

Section: X-ray Crystallographic Analysesmentioning

confidence: 99%

“…Due to these characteristics, it is possible to grow PO chains with variation of ethylene/α-olefin composition, either by sequential variation of the ethylene/α-olefin feed ratio or by means of a dual catalytic system with distinctly different monomer reactivity, enabling commercial production of olefin block copolymers composed of hard crystalline and soft rubbery PO blocks [19][20][21][22][23]. A method has also been developed to grow polystyrene (PS) chains further from the CCTP product (polyolefinyl) 2 Zn, thereby allowing for the synthesis of commercially relevant PO-block-PS and PS-block-PO-block-PS via one-pot synthesis [14,[24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Preparation of Pyridylamido Hafnium Complexes for Coordinative Chain Transfer Polymerization

et al. 2020

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The pyridylamido hafnium complex (I) discovered at Dow is a flagship catalyst among postmetallocenes, which are used in the polyolefin industry for PO-chain growth from a chain transfer agent, dialkylzinc. In the present work, with the aim to block a possible deactivation process in prototype compound I, the corresponding derivatives were prepared. A series of pyridylamido Hf complexes were prepared by replacing the 2,6-diisopropylphenylamido part in I with various 2,6-R2C6H3N-moieties (R = cycloheptyl, cyclohexyl, cyclopentyl, 3-pentyl, ethyl, or Ph) or by replacing 2-iPrC6H4C(H)- in I with the simple PhC(H)-moiety. The isopropyl substituent in the 2-iPrC6H4C(H)-moiety influences not only the geometry of the structures (revealed by X-ray crystallography), but also catalytic performance. In the complexes bearing the 2-iPrC6H4C(H)-moiety, the chelation framework forms a plane; however, this framework is distorted in the complexes containing the PhC(H)-moiety. The ability to incorporate α-olefin decreased upon replacing 2-iPrC6H4C(H)-with the PhC(H)-moiety. The complexes carrying the 2,6-di(cycloheptyl)phenylamido or 2,6-di(cyclohexyl)phenylamido moiety (replacing the 2,6-diisopropylphenylamido part in I) showed somewhat higher activity with greater longevity than did prototype catalyst I.

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“…The CCTP technique is judiciously utilized in the commercial production of olefin block copolymers at the Dow Chemical Company [10,20,21,22]. By performing anionic polymerization of styrene in a one-pot reaction after CCTP with I , it is also possible to synthesize polyolefin-polystyrene block copolymers [23,24,25]. In this context, many studies have been performed to detail I and to improve the catalytic performance by modifying the skeleton of I [26,27,28,29,30,31,32,33,34,35].…”

Section: Introductionmentioning

confidence: 99%

Preparation of Pincer Hafnium Complexes for Olefin Polymerization

et al. 2019

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Pincer-type [Cnaphthyl, Npyridine, Namido]HfMe2 complex is a flagship among the post-metallocene catalysts. In this work, various pincer-type Hf-complexes were prepared for olefin polymerization. Pincer-type [Namido, Npyridine, Namido]HfMe2 complexes were prepared by reacting in situ generated HfMe4 with the corresponding ligand precursors, and the structure of a complex bearing 2,6-Et2C6H3Namido moieties was confirmed by X-ray crystallography. When the ligand precursors of [(CH3)R2Si-C5H3N-C(H)PhN(H)Ar (R = Me or Ph, Ar = 2,6-diisopropylphenyl) were treated with in situ generated HfMe4, pincer-type [Csilylmethyl, Npyridine, Namido]HfMe2 complexes were afforded by formation of Hf-CH2Si bond. Pincer-type [Cnaphthyl, Sthiophene, Namido]HfMe2 complex, where the pyridine moiety in the flagship catalyst was replaced with a thiophene unit, was not generated when the corresponding ligand precursor was treated with HfMe4. Instead, the [Sthiophene, Namido]HfMe3-type complex was obtained with no formation of the Hf-Cnaphthyl bond. A series of pincer-type [Cnaphthyl, Npyridine, Nalkylamido]HfMe2 complexes was prepared where the arylamido moiety in the flagship catalyst was replaced with alkylamido moieties (alkyl = iPr, cyclohexyl, tBu, adamantyl). Structures of the complexes bearing isopropylamido and adamantylamido moieties were confirmed by X-ray crystallography. Most of the complexes cleanly generated the desired ion-pair complexes when treated with an equivalent amount of [(C18H37)2N(H)Me]+[B(C6F5)4]−, which showed negligible activity in olefin polymerization. Some complexes bearing bulky substituents showed moderate activities, even though the desired ion-pair complexes were not cleanly afforded.

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Polystyrene Chain Growth from Di-End-Functional Polyolefins for Polystyrene-Polyolefin-Polystyrene Block Copolymers

Cited by 13 publications

References 52 publications

Polystyrene Chain Growth Initiated from Dialkylzinc for Synthesis of Polyolefin-Polystyrene Block Copolymers

Polystyrene Chain Growth Initiated from Dialkylzinc for Synthesis of Polyolefin-Polystyrene Block Copolymers

Preparation of Pyridylamido Hafnium Complexes for Coordinative Chain Transfer Polymerization

Preparation of Pincer Hafnium Complexes for Olefin Polymerization

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