Journal ArticleDOI
TBD-Catalyzed Ring-Opening Polymerization of Alkyl-Substituted Morpholine-2,5-Dione Derivatives.
Michael Dirauf,Damiano Bandelli,Christine Weber,Helmar Görls,Michael Gottschaldt,Ulrich S. Schubert +5 more
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TLDR
Kinetic studies of the ROP reveal that the molar masses and dispersities could be well controlled, and Matrix-assisted laser desorption time-of-flight mass spectrometry indicates the presence of polymer chains with α-end groups derived from the initiator.Abstract:
In a two-step synthesis, five different alkyl-substituted morpholine-2,5-dione monomers were synthesized from the natural amino acids glycine, alanine, valine, leucine, and isoleucine. The heterocyclic compounds crystallize in a boat-like conformation and are polymerized via 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-catalyzed ring-opening polymerization (ROP) in tetrahydrofuran. Well-defined polymers could be obtained from the monomers based on valine, leucine, and isoleucine at a feed ratio of M/I/TBD = 100/1/0.5. Kinetic studies of the ROP reveal that the molar masses and dispersities (Đ < 1.2) could be well controlled, as confirmed by size exclusion chromatography and 1 H NMR spectroscopy. At conversions above 50%, the polymerization rate decreases and the dispersity slightly increases, presumably due to transesterification. Matrix-assisted laser desorption time-of-flight mass spectrometry indicates the presence of polymer chains with α-end groups derived from the initiator.read more
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Journal ArticleDOI
Synthesis and Controlled Organobase-Catalyzed Ring-Opening Polymerization of Morpholine-2,5-Dione Derivatives and Monomer Recovery by Acid-Catalyzed Degradation of the Polymers
TL;DR: Polydepsipeptides (PDPs) are strictly alternating copolymers of α-hydroxy acids and α-amino acids produced via the ring-opening polymerization (ROP) of morpholino-2,5-dione derivatives.
Journal ArticleDOI
Chemically recyclable polymer materials: polymerization and depolymerization cycles
Guangqiang Xu,Qinggang Wang +1 more
TL;DR: The design and synthesis of chemically recyclable polymers, which can be reutilized as their starting monomers or new value-added chemicals, have provided a practical approach to address the end-of-use problem as discussed by the authors .
Journal ArticleDOI
Extremely Rapid Polythioether Synthesis in the Presence of TBD
TL;DR: In this paper, a straightforward, novel, and extremely rapid method is developed for the synthesis of polythioether based on the reaction of dimethyl acetylenedicarboxylate with electron-deficient triple bond and 1,6-hexanedithiol in CHCl3 using an organobase 1,5,7-triazabicyclo[4.4.0]dec-5-ene at room temperature.
Journal ArticleDOI
Polyester Stereocomplexes Beyond PLA: Could Synthetic Opportunities Revolutionize Established Material Blending?
TL;DR: This review summarizes the current literature regarding stereocomplexation of different polyesters based on α- as well as β-hydroxy acids beyond the well-known poly(lactic acid) and synthetic approaches needed to obtain and analyze isotactic polyesters are summarized.
Journal ArticleDOI
Recent advances in degradable synthetic polymers for biomedical applications – Beyond polyesters
TL;DR: A review of the latest developments of (bio-degradable) synthetic polymers beyond polyesters can be found in this paper , where the authors scrutinize the recent synthetic developments of these polymer classes throughout the last 10 years, putting them into the context of applications that have arisen for less novel materials.
References
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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
TL;DR: In this article, the ring-opening polymerization (ROP) of cyclic esters such as lactide (LA), δ-valerolactone (VL), and e-caprolactone(CL) was achieved.
Journal ArticleDOI
Polylactic acid (PLA) controlled delivery carriers for biomedical applications.
TL;DR: PLA's application as drug-loaded nanoparticle drug carriers, such as liposomes, polymeric nanoparticles, dendrimers, and micelles, can encapsulate otherwise toxic hydrophobic anti-tumor drugs and evade systemic toxicities.
Journal ArticleDOI
Triazabicyclodecene: A Simple Bifunctional Organocatalyst for Acyl Transfer and Ring-Opening Polymerization of Cyclic Esters
Russell C. Pratt,Bas G. G. Lohmeijer,David A. Long,Robert M. Waymouth, ,§ and,James L. Hedrick +4 more
TL;DR: The simplicity of the reaction conditions, the ready commercial availability of the catalyst, and its high activity provide an accessible methodology to allow future studies of tailor-made polyesters.