Polycarbonates derived from green acids: immortal ring-opening polymerization of seven-membered cyclic carbonates
| Autor: | Osvaldo L. Casagrande, Sophie M. Guillaume, Pierre Brignou, Jean-François Carpentier, Marcelo Priebe Gil |
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| Přispěvatelé: | Institut des Sciences Chimiques de Rennes (ISCR), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Laboratório de Catálise Molecular, Instituto de Quimica-Universidade Federal do Rio Grande do Sul, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Polymers and Plastics
Bulk polymerization Stereochemistry Organic carbonate Substituent Ring opening polymerization Chemical reactivity 010402 general chemistry 01 natural sciences Medicinal chemistry Ring-opening polymerization Catalysis Yttrium complex Inorganic Chemistry chemistry.chemical_compound Regioselectivity Materials Chemistry Lewis acids and bases Plant origin Microstructure Aliphatic polymer Experimental study Living polymer 010405 organic chemistry Chemistry Organic Chemistry [CHIM.CATA]Chemical Sciences/Catalysis Lewis acid 0104 chemical sciences Catalytic reaction Monomer Polymerization Polycarbonate Preparation Oxygen heterocycle Catalyst activity Zinc complex Molecular structure Aluminium compound |
| Zdroj: | Macromolecules Macromolecules, American Chemical Society, 2010, 43 (19), pp.8007-8017. ⟨10.1021/ma1014098⟩ Macromolecules, 2010, 43 (19), pp.8007-8017. ⟨10.1021/ma1014098⟩ |
| ISSN: | 0024-9297 1520-5835 |
| DOI: | 10.1021/ma1014098⟩ |
| Popis: | International audience; Methyl substituted seven-membered ring carbonates (7CCs), namely, 4-methyl- and 5-methyl-1,3-dioxepan-2-one (α-Me7CC and β-Me7CC), have been synthesized in high yields (up to 70%) upon cyclization of the corresponding α,ω-diols issued from green renewable acids. ("Immortal") ring-opening polymerization of these monomers has been carried out using various catalysts combined with an alcohol acting as a co-initiator and a chain transfer agent. The Lewis acid Al(OTf)3, the organometallic complexes [(BDIiPr)Zn(N(SiMe3)2)] ((BDIiPr) = 2-((2,6-diisopropylphenyl)amido)-4-((2,6-diisopropylphenyl)-imino)-2-pentene] and [(ONOOrBu)Y(N(SiHMe2)2)(THF)] (ONOOtBu = amino-alkoxy-bis(phenolate)) or the organic 4-N,N-dimethylaminopyridine (DMAP), 1.5.7-triazabicyclo-[4.4.0]dec-5-ene (TBD) or 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) successfully afforded the corresponding poly(α- and β-Me7CC)s with quite good control and activities. The dissymmetry of the monomers raises the question ofcatalyst selectivity in the ring-opening of the 7CCs. Detailed microstructural analyses of the poly(7CC)s using 1H and 13C NMR and MALDI-ToF-MS techniques revealed (1) the higher regioselectivity with preferential ring-opening at the most hindered oxygen-acyl O-C(O)O bond, that is, closest to the α-Me substituent-- of the zinc-based system followed by the yttrium, as compared to the lack ofselectivity of the aluminum one, in the ring-opening polymerization (ROP) of α-Me7CC; (2) the absence of regioselectivity in the ROP of β-Me7CC, whichever the catalyst system used, most likely as a result of the OC(O)O further remote substitution site; (3) the expected α-hydroxy, ω-alkoxyester chain ends. Differential scanning calorimetry (DSC) analyses of these polymers underlined the influence of the position of the methyl substituent on the glass transition temperature. Noteworthy, this study represents the first synthesis of the β-Me7CC monomer and of the resulting polycarbonates. |
| Databáze: | OpenAIRE |
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