Nontoxic N -Heterocyclic Olefin Catalyst Systems for Well-Defined Polymerization of Biocompatible Aliphatic Polycarbonates.
| Autor: | Czysch C; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany., Dinh T; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany., Fröder Y; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany., Bixenmann L; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany., Komforth P; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany., Balint A; Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany., Räder HJ; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany., Naumann S; Institute of Polymer Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany., Nuhn L; Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.; Chair of Macromolecular Chemistry, Julius-Maximilians-Universität Würzburg, Röntgenring 11, 97070 Würzburg, Germany. |
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| Jazyk: | angličtina |
| Zdroj: | ACS polymers Au [ACS Polym Au] 2022 Jul 25; Vol. 2 (5), pp. 371-379. Date of Electronic Publication: 2022 Jul 25 (Print Publication: 2022). |
| DOI: | 10.1021/acspolymersau.2c00017 |
| Abstrakt: | Herein, N -heterocyclic olefins (NHOs) are utilized as catalysts for the ring-opening polymerization (ROP) of functional aliphatic carbonates. This emerging class of catalysts provides high reactivity and rapid conversion. Aiming for the polymerization of monomers with high side chain functionality, six-membered carbonates derived from 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) served as model compounds. Tuning the reactivity of NHO from predominant side chain transesterification at room temperature toward ring-opening at lowered temperatures (-40 °C) enables controlled ROP. These refined conditions give narrowly distributed polymers of the hydrophobic carbonate 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MTC-OBn) ( Đ < 1.30) at (pseudo)first-order kinetic polymerization progression. End group definition of these polymers demonstrated by mass spectrometry underlines the absence of side reactions. For the active ester monomer 5-methyl-5-pentafluorophenyloxycarbonyl-1,3-dioxane-2-one (MTC-PFP) with elevated side chain reactivity, a cocatalysis system consisting of NHO and the Lewis acid magnesium iodide is required to retune the reactivity from side chains toward controlled ROP. Excellent definition of the products ( Đ < 1.30) and mass spectrometry data demonstrate the feasibility of this cocatalyst approach, since MTC-PFP has thus far only been polymerized successfully using acidic catalysts with moderate control. The broad feasibility of our findings was further demonstrated by the synthesis of block copolymers for bioapplications and their successful nanoparticular assembly. High tolerability of NHO in vitro with concentrations ranging up to 400 μM (equivalent to 0.056 mg/mL) further emphasize the suitability as a catalyst for the synthesis of bioapplicable materials. The polycarbonate block copolymer mPEG Competing Interests: The authors declare no competing financial interest. (© 2022 The Authors. Published by American Chemical Society.) |
| Databáze: | MEDLINE |
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