1
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Omar R, Shaik M, Griggs C, Jensen JD, Boyd R, Oncel N, Webster DC, Du G. Star-shaped Poly(hydroxybutyrate)s from bio-based polyol cores via zinc catalyzed ring-opening polymerization of β-Butyrolactone. Eur Polym J 2021. [DOI: 10.1016/j.eurpolymj.2021.110756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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2
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Casey KC, Appiah JK, Robinson JR. Low-Symmetry β-Diketimine Aryloxide Rare-Earth Complexes: Flexible, Reactive, and Selective. Inorg Chem 2020; 59:14827-14837. [PMID: 32986427 DOI: 10.1021/acs.inorgchem.0c02170] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We report the synthesis, characterization, and reactivity of a new low-symmetry β-diketimine featuring a pendant amino(methyl)phenol donor and its corresponding heteroleptic rare-earth (RE) complexes. This includes the first structurally characterized examples of alcoholysis and insertion from an isolated REIII amide in a β-diketimine framework. The flexible methylene linkage leads to REIII complexes with tunable dynamic solution behavior that defines their stoichiometric and catalytic reactivity. The addition of a strong neutral donor ligand, tricyclohexylphosphine oxide, suppresses a prevalent catalyst degradation pathway (base-promoted elimination) and dramatically enhances the catalyst performance in the stereospecific ring-opening polymerization of rac-β-butyrolactone. Our results further demonstrate the importance of ligand reorganization in the stoichiometric and catalytic activity of REIII ions.
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Affiliation(s)
- Kerry C Casey
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912, United States
| | - Jude K Appiah
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912, United States
| | - Jerome R Robinson
- Department of Chemistry, Brown University, 324 Brook Street, Providence, Rhode Island 02912, United States
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3
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Dong X, Robinson JR. The role of neutral donor ligands in the isoselective ring-opening polymerization of rac-β-butyrolactone. Chem Sci 2020; 11:8184-8195. [PMID: 34123089 PMCID: PMC8163396 DOI: 10.1039/d0sc03507f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Isoenriched poly-3-hydroxybutyrate (P3HB) is a biodegradable material with properties similar to isotactic polypropylene, yet efficient routes to this material are lacking after 50+ years of extensive efforts in catalyst design. In this contribution, a novel lanthanum aminobisphenolate catalyst (1-La) can access isoenriched P3HB through the stereospecific ring-opening polymerization (ROP) of rac-β-butyrolactone (rac-BBL). Replacing the tethered donor group of a privileged supporting ligand with a non-coordinating benzyl substituent generates a catalyst whose reactivity and selectivity can be tuned with inexpensive achiral neutral donor ligands (e.g. phosphine oxides, OPR3). The 1-La/OPR3 (R = n-octyl, Ph) systems display high activity and are the most isoselective homogeneous catalysts for the ROP of rac-BBL to date (0 °C: Pm = 0.8, TOF ∼190 h−1). Combined reactivity and spectroscopic studies provide insight into the active catalyst structure and ROP mechanism. Both 1-La(TPPO)2 and a structurally related catalyst with a tethered donor group (2-Y) operate under chain-end stereocontrol; however, 2-RE favors formation of P3HB with opposite tacticity (syndioenriched) and its ROP activity and selectivity are totally unaffected by added neutral donor ligands. Our studies uncover new roles for neutral donor ligands in stereospecific ROP, including suppression of chain-scission events, and point to new opportunities for catalyst design. Simple achiral neutral donor ligands modify catalyst structure and function to enable access to isoenriched poly-3-hydroxybutyrate, a biodegradable material with properties similar to isotactic polypropylene.![]()
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Affiliation(s)
- Xiang Dong
- Department of Chemistry, Brown University 324 Brook St. Providence RI 02912 USA
| | - Jerome R Robinson
- Department of Chemistry, Brown University 324 Brook St. Providence RI 02912 USA
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4
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Gruszka W, Walker LC, Shaver MP, Garden JA. In Situ Versus Isolated Zinc Catalysts in the Selective Synthesis of Homo and Multi-block Polyesters. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c00277] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Weronika Gruszka
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Leah C. Walker
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
| | - Michael P. Shaver
- School of Natural Sciences, Department of Materials, The University of Manchester, Manchester M13 9PL, United Kingdom
- Henry Royce Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Jennifer A. Garden
- EaStCHEM School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, United Kingdom
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5
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Soobrattee S, Zhai X, Nyamayaro K, Diaz C, Kelley P, Ebrahimi T, Mehrkhodavandi P. Dinucleating Amino-Phenolate Platform for Zinc Catalysts: Impact on Lactide Polymerization. Inorg Chem 2020; 59:5546-5557. [PMID: 32223228 DOI: 10.1021/acs.inorgchem.0c00250] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We report imine- and amine-based dinucleating ligands bearing a bisphenol backbone and explore their coordination chemistry with zinc to form zinc alkyl, alkoxide, acetate, and amide complexes. Full characterization of the complexes shows that this ligand framework can support dinuclear and trinuclear complexes. We explore the reactivity of the zinc alkyl and alkoxide complexes as catalysts for the ring opening polymerization of lactide and compared this reactivity to analogous mononuclear complexes. We show that 1) The amine-based complexes are more reactive than the imine-based analogues; 2) The trinuclear zinc alkyl species show unusual control and reproducibility for lactide polymerization; and 3) The extent of bimetallic cooperation is hampered by the ability of the ligand framework to form trinuclear clusters.
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Affiliation(s)
- Shazia Soobrattee
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Xiaofang Zhai
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Kudzanai Nyamayaro
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Carlos Diaz
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Paul Kelley
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Tannaz Ebrahimi
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Parisa Mehrkhodavandi
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
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6
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Shaik M, Peterson J, Du G. Cyclic and Linear Polyhydroxylbutyrates from Ring-Opening Polymerization of β-Butyrolactone with Amido-Oxazolinate Zinc Catalysts. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b02096] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Muneer Shaik
- Department of Chemistry, University of North Dakota, 151 Cornell Street Stop 9024, Grand Forks, North Dakota 58202, United States
| | - Jhaiquashia Peterson
- Department of Chemistry, University of North Dakota, 151 Cornell Street Stop 9024, Grand Forks, North Dakota 58202, United States
| | - Guodong Du
- Department of Chemistry, University of North Dakota, 151 Cornell Street Stop 9024, Grand Forks, North Dakota 58202, United States
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7
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Osten KM, Mehrkhodavandi P. Indium Catalysts for Ring Opening Polymerization: Exploring the Importance of Catalyst Aggregation. Acc Chem Res 2017; 50:2861-2869. [PMID: 29087695 DOI: 10.1021/acs.accounts.7b00447] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Inexorably, the environmental persistence and damage caused by polyolefins have become major drawbacks to their continued long-term use. Global shifts in thinking from fossil-fuel to renewable biobased resources have urged researchers to focus their attention on substituting fossil-fuel based polymers with renewable and biodegradable alternatives on an industrial scale. The recent development of biodegradable polyesters from ring opening polymerization (ROP) of bioderived cyclic ester monomers has emerged as a promising new avenue toward this goal. Ever increasing numbers of metal-based initiators have been reported in the literature for the controlled ROP of cyclic esters, in particular for the polymerization of lactide to produce poly(lactic acid) (PLA). PLA has several material weaknesses, which hinder its use as a replacement for commodity plastics. Despite many advances in developing highly active and controlled catalysts for lactide polymerization, no single catalyst system has emerged to replace industrially used catalysts and provide access to PLA materials with improved properties. We reported the first example of indium(III) for the ring opening polymerization of lactide. Since then, indium(III) has emerged as a useful Lewis acid in initiators for the controlled polymerization of lactide and other cyclic esters. In particular, we have developed a large family of chiral dinuclear indium complexes bearing tridentate diaminophenolate ligands and tetradentate salen and salan ligands. Complexes within our tridentate ligand family are highly active initiators for the moderately isoselective living and immortal polymerization of rac-lactide, as well as other cyclic esters. We have shown that subtle steric effects influence aggregation in these systems, with polymerization typically proceeding through a dinuclear propagating species. In addition, profound effects on polymerization activities have been observed for central tertiary versus secondary amine donors in these and other related systems. In contrast, our well-controlled and highly active chiral indium salen systems are more isoselective than the tridentate analogues and polymerize lactide via a mononuclear propagating species. Again, we have noticed that subtle steric and electronic changes to the ligand can influence both polymerization activity and stereoselectivity via aggregation phenomena. Recently, we have reported a promising new chiral indium catalyst supported by a tetradentate salan ligand. This catalyst is remarkably water and air stable and can be activated by linear and branched alcohols to provide controlled access to multiblock copolymers in air. This catalyst represents an important step forward toward generating new, commercially relevant catalysts for ROP of cyclic esters to produce novel biodegradable polymers, and highlights the unique value of indium-based catalysts in the field.
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Affiliation(s)
- Kimberly M. Osten
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
| | - Parisa Mehrkhodavandi
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T1Z1, Canada
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8
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Ebrahimi T, Aluthge DC, Patrick BO, Hatzikiriakos SG, Mehrkhodavandi P. Air- and Moisture-Stable Indium Salan Catalysts for Living Multiblock PLA Formation in Air. ACS Catal 2017. [DOI: 10.1021/acscatal.7b01939] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Tannaz Ebrahimi
- Department
of Chemistry, University of British Columbia, Vancouver, BC Canada, V6T1Z1
- Department
of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC Canada, V6T1Z3
| | - Dinesh C. Aluthge
- Department
of Chemistry, University of British Columbia, Vancouver, BC Canada, V6T1Z1
| | - Brian O. Patrick
- Department
of Chemistry, University of British Columbia, Vancouver, BC Canada, V6T1Z1
| | - Savvas G. Hatzikiriakos
- Department
of Chemical and Biological Engineering, University of British Columbia, Vancouver, BC Canada, V6T1Z3
| | - Parisa Mehrkhodavandi
- Department
of Chemistry, University of British Columbia, Vancouver, BC Canada, V6T1Z1
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9
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Ebrahimi T, Taghipour H, Grießl D, Mehrkhodavandi P, Hatzikiriakos SG, van Ruymbeke E. Binary Blends of Entangled Star and Linear Poly(hydroxybutyrate): Effect of Constraint Release and Dynamic Tube Dilation. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02653] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Tannaz Ebrahimi
- Department
of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall Vancouver, Vancouver, British Columbia Canada
- Department
of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia Canada
| | - Hamid Taghipour
- The
Division of Bio- and Soft Matter (BSMA), Institute of Condensed Matter
and Nanosciences (IMCN), Université catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
| | - Desiree Grießl
- Department
of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall Vancouver, Vancouver, British Columbia Canada
- Chemical
Technology, Technical University of Munich, Munich, Germany
| | - Parisa Mehrkhodavandi
- Department
of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia Canada
| | - Savvas G. Hatzikiriakos
- Department
of Chemical and Biological Engineering, The University of British Columbia, 2360 East Mall Vancouver, Vancouver, British Columbia Canada
| | - Evelyne van Ruymbeke
- The
Division of Bio- and Soft Matter (BSMA), Institute of Condensed Matter
and Nanosciences (IMCN), Université catholique de Louvain (UCL), Louvain-la-Neuve, Belgium
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10
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Chile LE, Ebrahimi T, Wong A, Aluthge DC, Hatzikiriakos SG, Mehrkhodavandi P. Impact of aryloxy initiators on the living and immortal polymerization of lactide. Dalton Trans 2017; 46:6723-6733. [DOI: 10.1039/c7dt00990a] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This report describes two different methodologies for the synthesis of aryl end-functionalized poly(lactide)s (PLAs) catalyzed by indium complexes.
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Affiliation(s)
- L.-E. Chile
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
- Department of Chemical and Biological Engineering
| | - T. Ebrahimi
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
- Department of Chemical and Biological Engineering
| | - A. Wong
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - D. C. Aluthge
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
| | - S. G. Hatzikiriakos
- Department of Chemical and Biological Engineering
- University of British Columbia
- Vancouver
- Canada
| | - P. Mehrkhodavandi
- Department of Chemistry
- University of British Columbia
- Vancouver
- Canada
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11
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Ebrahimi T, Aluthge DC, Hatzikiriakos SG, Mehrkhodavandi P. Highly Active Chiral Zinc Catalysts for Immortal Polymerization of β-Butyrolactone Form Melt Processable Syndio-Rich Poly(hydroxybutyrate). Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01908] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Tannaz Ebrahimi
- Department of Chemistry and ‡Department of
Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Dinesh C. Aluthge
- Department of Chemistry and ‡Department of
Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Savvas G. Hatzikiriakos
- Department of Chemistry and ‡Department of
Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Parisa Mehrkhodavandi
- Department of Chemistry and ‡Department of
Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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12
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Ebrahimi T, Mamleeva E, Yu I, Hatzikiriakos SG, Mehrkhodavandi P. The Role of Nitrogen Donors in Zinc Catalysts for Lactide Ring-Opening Polymerization. Inorg Chem 2016; 55:9445-53. [PMID: 27580374 DOI: 10.1021/acs.inorgchem.6b01722] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The electronic effects of nitrogen donors in zinc catalysts for ring-opening polymerization of cyclic esters were investigated. Alkyl and benzyloxy zinc complexes supported by tridentate diamino- and aminoimino phenolate ligands were synthesized, and their solid-state and solution structures characterized. The solution-state structures showed that the alkyl complexes are mononuclear, while the alkoxy complexes are dimeric with the ligands coordinated with different denticities depending on the nature of the ligand donors. The catalytic activities of these compounds toward the ring-opening polymerization of racemic lactide were studied and showed that catalysts with secondary and imine nitrogen donors are more active than analogues with tertiary amines.
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Affiliation(s)
- Tannaz Ebrahimi
- Department of Chemistry, and ‡Department of Chemical and Biological Engineering, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Emiliya Mamleeva
- Department of Chemistry, and ‡Department of Chemical and Biological Engineering, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Insun Yu
- Department of Chemistry, and ‡Department of Chemical and Biological Engineering, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Savvas G Hatzikiriakos
- Department of Chemistry, and ‡Department of Chemical and Biological Engineering, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Parisa Mehrkhodavandi
- Department of Chemistry, and ‡Department of Chemical and Biological Engineering, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
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13
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Barouti G, Liow SS, Dou Q, Ye H, Orione C, Guillaume SM, Loh XJ. New Linear and Star-Shaped Thermogelling Poly([R]-3-hydroxybutyrate) Copolymers. Chemistry 2016; 22:10501-12. [PMID: 27345491 DOI: 10.1002/chem.201601404] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Indexed: 12/20/2022]
Abstract
The synthesis of multi-arm poly([R]-3-hydroxybutyrate) (PHB)-based triblock copolymers (poly([R]-3-hydroxybutyrate)-b-poly(N-isopropylacrylamide)-b-[[poly(methyl ether methacrylate)-g-poly(ethylene glycol)]-co-[poly(methacrylate)-g-poly(propylene glycol)]], PHB-b-PNIPAAM-b-(PPEGMEMA-co-PPPGMA), and their subsequent self-assembly into thermo-responsive hydrogels is described. Atom transfer radical polymerization (ATRP) of N-isopropylacrylamide (NIPAAM) followed by poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and poly(propylene glycol) methacrylate (PPGMA) was achieved from bromoesterified multi-arm PHB macroinitiators. The composition of the resulting copolymers was investigated by (1) H and (13) C J-MOD NMR spectroscopy as well as size-exclusion chromatography (SEC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The copolymers featuring different architectures and distinct hydrophilic/hydrophobic contents were found to self-assemble into thermo-responsive gels in aqueous solution. Rheological studies indicated that the linear one-arm PHB-based copolymer tend to form a micellar solution, whereas the two- and four-arm PHB-based copolymers afforded gels with enhanced mechanical properties and solid-like behavior. These investigations are the first to correlate the gelation properties to the arm number of a PHB-based copolymer. All copolymers revealed a double thermo-responsive behavior due to the NIPAAM and PPGMA blocks, thus allowing first the copolymer self-assembly at room temperature, and then the delivery of a drug at body temperature (37 °C). The non-significant toxic response of the gels, as assessed by the cell viability of the CCD-112CoN human fibroblast cell line with different concentrations of the triblock copolymers ranging from 0.03 to 1 mg mL(-1) , suggest that these PHB-based thermo-responsive gels are promising candidate biomaterials for drug-delivery applications.
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Affiliation(s)
- Ghislaine Barouti
- Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 Avenue du Général Leclerc, 35042, Rennes Cedex, France
- Institute of Materials Research and Engineering (IMRE), 3 Research Link, Singapore, 117602, Singapore
| | - Sing Shy Liow
- Institute of Materials Research and Engineering (IMRE), 3 Research Link, Singapore, 117602, Singapore
| | - Qingqing Dou
- Institute of Materials Research and Engineering (IMRE), 3 Research Link, Singapore, 117602, Singapore
| | - Hongye Ye
- Institute of Materials Research and Engineering (IMRE), 3 Research Link, Singapore, 117602, Singapore
| | - Clément Orione
- Centre Régional de Mesures Physiques de l'Ouest, Université de Rennes 1, Campus de Beaulieu, 263 Avenue du Général Leclerc, 35042, Rennes Cedex, France
| | - Sophie M Guillaume
- Institut des Sciences Chimiques de Rennes, UMR 6226 CNRS, Université de Rennes 1, Campus de Beaulieu, 263 Avenue du Général Leclerc, 35042, Rennes Cedex, France.
| | - Xian Jun Loh
- Institute of Materials Research and Engineering (IMRE), 3 Research Link, Singapore, 117602, Singapore.
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore.
- Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, 168751, Singapore.
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14
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Perry MR, Ebrahimi T, Morgan E, Edwards PM, Hatzikiriakos SG, Schafer LL. Catalytic Synthesis of Secondary Amine-Containing Polymers: Variable Hydrogen Bonding for Tunable Rheological Properties. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00306] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Tannaz Ebrahimi
- Department
of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | | | | | - Savvas G. Hatzikiriakos
- Department
of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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15
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Kremer AB, Osten KM, Yu I, Ebrahimi T, Aluthge DC, Mehrkhodavandi P. Dinucleating Ligand Platforms Supporting Indium and Zinc Catalysts for Cyclic Ester Polymerization. Inorg Chem 2016; 55:5365-74. [PMID: 27187767 DOI: 10.1021/acs.inorgchem.6b00358] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The synthesis of the first alkoxide-bridged indium complex supported by a chiral dinucleating ligand platform (1), along with its zinc analogue (2), is reported. Both complexes are synthesized in a one-pot reaction starting from a chiral dinucleating bis(diamino)phenolate ligand platform, sodium ethoxide, and respective metal salts. The dinucleating indium analogue (7) based on an achiral ligand backbone is also reported. Indium complexes bearing either the chiral or achiral ligand catalyze the ring-opening polymerization of racemic lactide (rac-LA) to afford highly heterotactic poly(lactic acid) (PLA; Pr > 0.85). The indium complex bearing an achiral ligand affords essentially atactic PLA from meso-LA. The role of the dinucleating ligand structure in catalyst synthesis and polymerization activity is discussed.
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Affiliation(s)
- Alexandre B Kremer
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Kimberly M Osten
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Insun Yu
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Tannaz Ebrahimi
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Dinesh C Aluthge
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
| | - Parisa Mehrkhodavandi
- Department of Chemistry, University of British Columbia , 2036 Main Mall, Vancouver, British Columbia V6T 1Z4, Canada
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16
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Robinson JW, Zhou Y, Qu J, Erck R, Cosimbescu L. Effects of star-shaped poly(alkyl methacrylate) arm uniformity on lubricant properties. J Appl Polym Sci 2016. [DOI: 10.1002/app.43611] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Yan Zhou
- Oak Ridge National Laboratory; Oak Ridge Tennessee
| | - Jun Qu
- Oak Ridge National Laboratory; Oak Ridge Tennessee
| | - Robert Erck
- Argonne National Laboratory; Lemont Illinois
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17
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Wang H, Guo J, Yang Y, Ma H. Diastereoselective synthesis of chiral aminophenolate magnesium complexes and their application in the stereoselective polymerization of rac-lactide and rac-β-butyrolactone. Dalton Trans 2016; 45:10942-53. [DOI: 10.1039/c6dt01126h] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A series of magnesium silylamido complexes supported by chiral aminophenolate ligands were synthesized, and their catalytic behaviors toward the ring-opening polymerization of rac-lactide (LA) and rac-β-butyrolactone (BBL) were explored.
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Affiliation(s)
- Haobing Wang
- Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Jianshuang Guo
- Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Yang Yang
- Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
| | - Haiyan Ma
- Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry
- East China University of Science and Technology
- Shanghai 200237
- People's Republic of China
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