Journal ArticleDOI
Guanidine and Amidine Organocatalysts for Ring-Opening Polymerization of Cyclic Esters
Bas G. G. Lohmeijer,Russell C. Pratt,Frank A. Leibfarth,John W. Logan,David A. Long,Andrew P. Dove,Fredrik Nederberg,Jeongsoo Choi,Charles G. Wade,Robert M. Waymouth,James L. Hedrick +10 more
TLDR
In this article, the ring-opening polymerization (ROP) of cyclic esters such as lactide (LA), δ-valerolactone (VL), and e-caprolactone(CL) was achieved.Abstract:
1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD), N-methyl-TBD (MTBD), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) are effective organocatalysts for the ring-opening polymerization (ROP) of cyclic esters such as lactide (LA), δ-valerolactone (VL), and e-caprolactone (CL). TBD is shown to polymerize LA, VL, and CL in a fast and controlled manner, whereas MTBD and DBU polymerized LA and addition of a thiourea cocatalyst led to the ROP of VL and CL being achieved. Each of the catalysts produced polymers displaying high end group fidelity, good correlation between theoretical and observed molecular weight, and linear relationships between conversion and molecular weight. The enhanced activity of TBD relative to MTBD and DBU is attributed to its bifunctionality, enabling the simultaneous activation of both the cyclic ester monomer and the alcohol group of the initiator/propagating species. Temperature-dependent NMR studies generated individual association constants for MTBD with benzyl alcohol and thiourea with VL. ...read more
Citations
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Journal ArticleDOI
Molecular bionics – engineering biomaterials at the molecular level using biological principles
Laura Rodríguez-Arco,Alessandro Poma,Lorena Ruiz-Pérez,Edoardo Scarpa,Kamolchanok Ngamkham,Giuseppe Battaglia +5 more
TL;DR: Some of the recent progress in the field of molecular bionics are reviewed with the final aim of providing with design rules to ensure their stability in biological media as well as to engineer novel functionalities which enable navigating the human body.
Journal ArticleDOI
Morphology Under Control: Engineering Biodegradable Stomatocytes.
Imke A. B. Pijpers,Loai K. E. A. Abdelmohsen,David S. Williams,David S. Williams,Jan C. M. van Hest +4 more
TL;DR: This work uncovers the supramolecular potential of PEG–PDLLA copolymers by exploring the physicochemical determinants that result in the transformation of spherical polymersomes into stomatocytes, and demonstrates osmotically inducedStomatocyte formation as a consequence of changes in PEG solvation, inducing negative spontaneous membrane curvature.
Journal ArticleDOI
Organocatalysis: A Paradigm Shift in the Synthesis of Aliphatic Polyesters and Polycarbonates
Kazuki Fukushima,Kyoko Nozaki +1 more
Journal ArticleDOI
Gold Nanorods with Phase‐Changing Polymer Corona for Remotely Near‐Infrared‐Triggered Drug Release
Ji Liu,Ji Liu,Christophe Detrembleur,Bruno Grignard,Marie-Claire De Pauw-Gillet,Stéphane Mornet,Mona Tréguer-Delapierre,Yannick Petit,Christine Jérôme,Etienne Duguet +9 more
TL;DR: A new drug-delivery system (DDS) that is comprised of a near-infrared (NIR)-light-sensitive gold-nanorod ( GNR) core and a phase-changing poly(ε-caprolactone)-b-poly(ethylene glycol) polymer corona (GNR@PCL-b-PEG), aimed at addressing the different requirements for therapeutic treatments is reported.
Journal ArticleDOI
Biomorphic Engineering of Multifunctional Polylactide Stomatocytes toward Therapeutic Nano-Red Blood Cells.
Jingxin Shao,Imke A. B. Pijpers,Shoupeng Cao,David S. Williams,Xuehai Yan,Junbai Li,Loai K. E. A. Abdelmohsen,Jan C. M. van Hest +7 more
TL;DR: E engineered polymeric stomatocytes are presented as a structural and functional mimic of red blood cells (RBCs) with multifunctional therapeutic features, which constitutes a highly promising platform for future clinical application.
References
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Journal ArticleDOI
Controlled ring-opening polymerization of lactide and glycolide.
TL;DR: This work focuses on the characterization of the phytochemical components of Lactide ROP and their role in the regulation of cell reprograming.
Journal ArticleDOI
Polymerization of Lactide with Zinc and Magnesium β-Diiminate Complexes: Stereocontrol and Mechanism
Bradley M. Chamberlain,Ming Cheng,David Roger Moore,Tina M. Ovitt,Emil B. Lobkovsky,Geoffrey W. Coates +5 more
TL;DR: The substituents on the beta-diiminate ligand exert a significant influence upon the course of the polymerizations, affecting both the degree of stereoselectivity and the rate of polymerization.
Journal ArticleDOI
A review of biodegradable polymers: uses, current developments in the synthesis and characterization of biodegradable polyesters, blends of biodegradable polymers and recent advances in biodegradation studies
TL;DR: A review of the uses of biodegradable polymers in terms of their relevance within current plastic waste management of packaging materials, biomedical applications and other uses is presented in this paper.
Journal ArticleDOI
Extension of the self-consistent spectrophotometric basicity scale in acetonitrile to a full span of 28 pKa units: unification of different basicity scales.
Ivari Kaljurand,Agnes Kütt,Lilli Sooväli,Toomas Rodima,Vahur Mäemets,and Ivo Leito,Ilmar A. Koppel +6 more
TL;DR: The earlier compiled self-consistent spectrophotometric basicity scale in acetonitrile (AN) was expanded to range from 3.8 to 32.0 pK(a) units, that is 28 orders of magnitude, and 54 new relative basicity measurements were carried out and 37 new compounds were introduced to the scale.
Journal ArticleDOI
Stereochemistry of Lactide Polymerization with Chiral Catalysts: New Opportunities for Stereocontrol Using Polymer Exchange Mechanisms
Tina M. Ovitt,Geoffrey W. Coates +1 more
TL;DR: A polymer exchange mechanism is proposed to account for the PLA microstructures resulting from rac-4, which polymerizes meso-lactide to syndiotactic poly(lactic acid) (PLA) and heterotactic and isotactic stereoblock PLA, respectively.