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Burgenson WR, Wentz CM, Sita LR. Tailoring Glass Transition Temperature in a Series of Poly(methylene-1,3-cyclopentane- stat-cyclohexane) Statistical Copolymers. ACS Macro Lett 2023; 12:101-106. [PMID: 36598863 DOI: 10.1021/acsmacrolett.2c00706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A systematic investigation of the synthesis and characterization of a new class of amorphous atactic cis, trans poly(methylene-1,3-cyclopentane-stat-cyclohexane) statistical copolymers (I) is reported. Production of different grades of I that vary with respect to the ratio of 5- and 6-membered cycloalkane repeat units was achieved through the living coordinative chain transfer cyclopolymerization of different initial feed ratios of 1,5-hexadiene and 1,6-heptadiene comonomers. It was determined that the glass transition temperature, Tg, of I can be systematically increased from -16 to 100 °C as a function of increasing 6-membered ring content, although not in a strictly linear fashion. It was further determined that a small level of 6-membered ring content is sufficient to disrupt the crystallinity of the limiting atactic cis, trans poly(methylene-1,3-cyclopentane) (PMCP) homopolymer that possesses a melting temperature, Tm, of 98 °C. These results establish a foundation for future potential technological applications of this unique class of polyolefin copolymers.
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Affiliation(s)
- William R Burgenson
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Charlotte M Wentz
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Lawrence R Sita
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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2
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Investigation of relative stabilities of CPAM zirconium cycloalkylmethyl vs isomeric ω-alkenyl complexes: Crystal structures of the cyclobutylmethyl and cyclopentylmethyl complexes. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.116100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Kuzminski BRS, Fischbach DM, Yap GPA, Sita LR. Migratory Insertion into a Hafnium–Phenyl Bond and a Ligand-Assisted Mechanism for Reversible Chain Transfer in the Living Coordinative Polymerization of Olefins. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Brendan R. S. Kuzminski
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States,
| | - Danyon M. Fischbach
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States,
| | - Glenn P. A. Yap
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Lawrence R. Sita
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States,
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Tran TV, Lee E, Nguyen YH, Nguyen HD, Do LH. Customizing Polymers by Controlling Cation Switching Dynamics in Non-Living Polymerization. J Am Chem Soc 2022; 144:17129-17139. [PMID: 36069706 DOI: 10.1021/jacs.2c07098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Controlling the chain growth process in non-living polymerization reactions is difficult because chain termination typically occurs faster than the time it takes to apply an external trigger. To overcome this limitation, we have developed a strategy to regulate non-living polymerizations by exploiting the chemical equilibria between a metal catalyst and secondary metal cations. We have prepared two nickel phenoxyphosphine-polyethylene glycol variants, one with 2-methoxyphenyl (Ni1) and another with 2,6-dimethoxyphenyl (Ni2) phosphine substituents. Ethylene polymerization studies using these complexes in the presence of alkali salts revealed that chain growth is strongly dependent on electronic effects, whereas chain termination is dependent on both steric and electronic effects. By adjusting the solvent polarity, we can favor polymerizations via non-switching or dynamic switching modes. For example, in a 100:0.2 mixture of toluene/diethyl ether, reactions of Ni1 and both Li+ and Na+ cations in the presence of ethylene yielded bimodal polymers with different relative fractions depending on the Li+/Na+ ratio used. In a 98:2 mixture of toluene/diethyl ether, reactions of Ni2 and Cs+ in the presence of ethylene generated monomodal polyethylene with dispersity <2.0 and increasing molecular weight as the amount of Cs+ added increased. Solution studies by NMR spectroscopy showed that cation exchange between the nickel complexes and alkali cations in 98:2 toluene/diethyl ether is fast on the NMR time scale, which supports our proposed dynamic switching mechanism.
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Affiliation(s)
- Thi V Tran
- Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Eryn Lee
- Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Yennie H Nguyen
- Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Hieu D Nguyen
- Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
| | - Loi H Do
- Department of Chemistry, University of Houston, 4800 Calhoun Road, Houston, Texas 77004, United States
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Burkey AA, Fischbach DM, Wentz CM, Beers KL, Sita LR. Highly Versatile Strategy for the Production of Telechelic Polyolefins. ACS Macro Lett 2022; 11:402-409. [PMID: 35575371 DOI: 10.1021/acsmacrolett.2c00108] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A general and versatile synthetic strategy for producing practical quantities of a wide range of phenyl-group-terminated hetero- and homotelechelic semicrystalline polyethenes and amorphous atactic and semicrystalline isotactic poly(α-olefins) is reported. The phenyl groups serve as synthons for functionalities of additional classes of telechelic polyolefins that can be "unmasked" through simple high yielding postpolymerization reactions. A demonstration of the value of these materials as building blocks for structural classes of polyolefin-based synthetic polymers was provided by syntheses of well-defined polyolefin-polyester di- and triblock copolymers that were shown to adopt microphase-segregated nanostructured mesophases in the condensed phase.
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Affiliation(s)
- Aaron A. Burkey
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Danyon M. Fischbach
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Charlotte M. Wentz
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Kathryn L. Beers
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Lawrence R. Sita
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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Wallace MA, Burkey AA, Sita LR. Phenyl-Terminated Polyolefins via Living Coordinative Chain Transfer Polymerization with ZnPh 2 as a Chain Transfer Agent. ACS Catal 2021. [DOI: 10.1021/acscatal.1c02038] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Mark A. Wallace
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Aaron A. Burkey
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Lawrence R. Sita
- Laboratory for Applied Catalyst Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, United States
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