New Polymer Structures

Vogl, Otto; Corley, L. S.; Jaycox, Gary D.; Harris, William J.; Malanga, M.; Lohmann, Dieter; Bansleben, Donald A.; Muggee, John; Purgett, Mark D.

doi:10.1080/00222338508056622

Cited by 19 publications

(6 citation statements)

References 24 publications

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“…Although some homopolymerizations 20,24-29 and block-copolymerizations − are possible, they involve mechanisms 20,24,25 different from Ziegler−Natta-type polymerization of ethylene/α-olefins. , Thus, the random copolymerizations cannot proceed. Hence, the attempts of incorporating polar groups into a polymer chain must employ alternative approaches, such as functional group protection and use of special monomers, ,− or chemical modifications of the polymer. − Design of an effective catalyst for controlled, direct copolymerizations still remains among the not yet achieved goals of organometallic chemistry. Here, the use of less oxophilic, late-transition-metal complexes has shown some promise, as demonstrated by some recent pioneering studies. − Unlike its Ni-based analogue, the Brookhart Pd-diimine catalyst − has been shown to copolymerize 55,56 ethylene and higher α-olefins with acrylates and vinyl ketones.…”

Section: Introductionmentioning

confidence: 99%

DFT Studies on the Copolymerization of α-Olefins with Polar Monomers: Comonomer Binding by Nickel- and Palladium-Based Catalysts with Brookhart and Grubbs Ligands

Michalak

Ziegler

2001

Organometallics

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Gradient-corrected density functional theory has been used to study the polar monomer binding mode in complexes with Ni-and Pd-based Brookhart-diimine (cationic) and Grubbssalicylaldiminato (neutral) catalysts. Methyl acrylate and vinyl acrylate, as well as their fluorinated derivatives, have been studied as the comonomers in the copolymerization with R-olefins. Two binding modes have been considered: the π-complexes in which a polar monomer is bound by its olefinic functionality, and the O-complexes with a monomer bound by its carbonyl oxygen. The role of the electronic and the steric effects has been investigated, by considering the simplified (generic) models and the examples of the real catalysts. An energy decomposition of the contributions to the binding energies has been performed. The results show that for the Pd-based Brookhart system (active copolymerization catalyst) the π-complex is preferred, while for its Ni analogue (inactive) the O-complex is more stable. Further, the difference between Ni-and Pd-systems has mainly a steric (electrostatic + Pauli repulsion) origin: there is practically no difference in the orbital-interaction contribution to the binding energy between Ni-and Pd-based systems, as far as a comparison between the two binding modes is concerned. For the fluorinated monomers, the preference of the O-complex is decreased or reversed. However, the binding energies of both the π-and O-complexes are affected. In the complexes with Grubbs catalyst the π-complexes are strongly preferred for both the Ni-and Pd-based systems. The presence of bulky substituents on the catalysts results in a decrease in the binding energies of both the π-and O-complexes; the preference of the binding mode is not affected. Finally, the relative binding constants of the ethylene, propylene, and acrylate in the complexes involving the real Pd-Brookhart system agree with the experimental data for a similar catalyst: the ethylene complexes are most stable, followed by those of propylene and acrylate.

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Section: Introductionmentioning

confidence: 99%

DFT Studies on the Copolymerization of α-Olefins with Polar Monomers: Comonomer Binding by Nickel- and Palladium-Based Catalysts with Brookhart and Grubbs Ligands

Michalak

Ziegler

2001

Organometallics

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“…Copolymerization of ethylene and propylene with alkyl acrylates using palladium(II) catalysts gave high molar mass copolymers. Yasuda described organolanthanide(III)-initiated block copolymerizations of ethylene with alkyl methacrylates and lactones. , Although Ziegler−Natta catalysts are known for their intolerance to Lewis bases due to their highly oxophilic nature, − zirconocene/methylaluminoxane (MAO) catalysts were successful in copolymerizing ethylene and propylene with 1-hydroxy-10-undecene, , 1-chloro-10-undecene, N , N -bis(trimethylsilyl)-1-amino-10-undecene, and an o -heptenylphenol derivative . However, the interaction between MAO and polar Lewis basic monomers is unclear, and to some extent, the polymerization activity rose with an increasing MAO concentration.…”

Section: Introductionmentioning

confidence: 99%

Metallocene/Borate-Catalyzed Polymerization of Amino-Functionalized α-Olefins

et al. 1998

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Cationic metallocene/borate catalysts, generated from zirconocene dimethyl compounds, L n ZrMe2, and anilinium borate, [HNMe2Ph]+[B(C6F5)4]-, were used to polymerize 5-amino-1-pentenes and one 4-amino-1-butene with dimethyl, diethyl, diisopropyl, or diphenyl substitution patterns on nitrogen. The monomer 5-(N,N-diisopropylamino)-1-pentene showed the highest activity with Cp*2ZrMe2/borate and was used for all further investigations. The catalytic system Cp*2ZrMe2/borate was 4 times more active than the corresponding methylaluminoxane-based system and 180 times more active than the heterogeneous system, TiCl3/Al(i-Bu)3. 1-Hexene and 5-(N,N-diisopropylamino)-1-pentene were polymerized with Cp*2ZrMe2 and rac-ethylenebis(tetrahydroindenyl) zirconium dimethyl, rac-EB(THI)ZrMe2. Polymerization of both monomers with Cp*2ZrMe2 displayed similar activities. Hexene polymerizations with rac-EB(THI)ZrMe2 were 30 times more active than those with aminopentene. 5-(N,N-Diisopropylamino)-1-pentene polymerizations gave rise to isotactic poly(aminopentene) with C 2 symmetric catalysts, syndiotactic polymer with a C s symmetric catalyst, and atactic polymer with achiral catalyst precursors.

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“…A well-known limitation of conventional Ziegler−Natta catalyst systems is their intolerance to most functional groups (ethers, esters, amines, alcohols, and carboxylic acids) . Previous attempts to directly homo- or copolymerize various functionalized α-olefin monomers met with limited success due to a severe loss of activity caused by catalyst deactivation. − On the other hand, zirconocene/methylalumoxane (MAO) catalysts were to a certain extent successful in copolymerizing ethylene and propylene with 1-hydroxy-10-undecene, , 1-chloro-10-undecene, N , N -bis(trimethylsilyl)-1-amino-10-undecene, silsesquioxane-functionalized decene, an o -heptenylphenol derivative, and borane-functionalized α-olefins. , …”

Section: Introductionmentioning

confidence: 99%

Metallocene/Borate-Catalyzed Copolymerization of 5-N,N-Diisopropylamino-1-pentene with 1-Hexene or 4-Methyl-1-pentene

et al. 1998

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Metallocene/borate catalysts, generated from zirconocene dimethyl compounds, L n ZrMe2, and anilinium borate, [HNMe2Ph]+[B(C6F5)4]-, were used to copolymerize 5-N,N-diisopropylamino-1-pentene with 1-hexene and 4-methyl-1-pentene. The selected zirconocenes, bis(pentamethylcyclopentadienyl)zirconium(IV) dimethyl (Cp*2ZrMe2) and rac-ethylenebis(4,5,6,7-tetrahydroindenyl)zirconium(IV) dimethyl (rac-EB(THI)ZrMe2), provided atactic and isotactic materials, respectively. The isotactic polymers produced were amorphous or crystalline depending of the monomer. The calculated reactivity ratios for the copolymerization of 5-N,N-diisopropylamino-1-pentene with 1-hexene and metallocene rac-EB(THI)ZrMe2 indicate that this system approximates an ideal azeotropic copolymerization with r 1 = 1.11 and r 2 = 0.87. Estimates for the reactivity ratios for the copolymerization of 5-N,N-diisopropylamino-1-pentene with 4-methyl-1-pentene were r 1 = 3 and r 2 = 1 for rac-EB(THI)ZrMe2 and r 1 = 5 and r 2 = 0.5 for Cp*2ZrMe2. The polymerization of 1-hexene in the presence of the saturated 1-N,N-diisopropylaminopentane with rac-EB(THI)ZrMe2/borate was compared with analogous copolymerizations of 1-hexene/5-N,N-diisopropylamino-1-pentene. The aminopentene was more effective than the aminopentane in inhibiting the rate of total monomer conversion, implicating both intra- and intermolecular mechanisms for inhibition by the amine. Copolymers of 4-methyl-1-pentene/5-N,N-diisopropylamino-1-pentene produced with rac-ethylenebisindenyl zirconium(IV) dimethyl (rac-EBIZrMe2)/borate have higher decomposition temperatures with increasing amounts of aminopentene. This copolymer can be protonated with HCl to yield a methanol-soluble material.

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New Polymer Structures

Cited by 19 publications

References 24 publications

DFT Studies on the Copolymerization of α-Olefins with Polar Monomers: Comonomer Binding by Nickel- and Palladium-Based Catalysts with Brookhart and Grubbs Ligands

DFT Studies on the Copolymerization of α-Olefins with Polar Monomers: Comonomer Binding by Nickel- and Palladium-Based Catalysts with Brookhart and Grubbs Ligands

Metallocene/Borate-Catalyzed Polymerization of Amino-Functionalized α-Olefins

Metallocene/Borate-Catalyzed Copolymerization of 5-N,N-Diisopropylamino-1-pentene with 1-Hexene or 4-Methyl-1-pentene

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