scholarly journals Ring-opening polymerization of rac-lactide and ε-caprolactone using zinc and calcium salicylaldiminato complexes

2012 ◽  
Vol 90 (5) ◽  
pp. 419-426 ◽  
Author(s):  
Joshua B. L. Gallaway ◽  
Justin R. K. McRae ◽  
Andreas Decken ◽  
Michael P. Shaver
Keyword(s):  
Ring Opening ◽  
Polymeric Materials ◽  
Ring Opening Polymerization ◽  
Schiff Base Complexes ◽  
Tridentate Ligand ◽  
Poly Lactic Acid ◽  
Catalyst Composition ◽  
Calcium Complexes ◽  
Calcium Catalysts ◽  
Tridentate Schiff Base

Tridentate Schiff base complexes of zinc and calcium were prepared and tested in the ring-opening polymerization of ε-caprolactone and rac-lactide to generate biodegradable polymeric materials from biocompatible metals. Alteration of the pendant donor arm attached to the imine backbone provides some control over catalyst composition and polymerization activity. Complexes of the formula [ONN]ZnN(SiMe3)2, where [ONN] = 2-(N-donor arm-imine)[4,6-di(tert-butyl)phenoxide], were isolated with ethyldimethylamine, ethylpiperidine, and ethylmorpholine substituents, while disproportionation led to the isolation of [ONN]2Zn complexes with methylpyridine, quinoline, and ethyldiisopropylamine derivatives, two of which were crystallographically characterized. Calcium complexes were more stable and novel [ONN]CaN(SiMe3)2 complexes with ethylpiperidine and ethyldiisopropylamine substituents were reported. Zinc and calcium catalysts coordinated to a single tridentate ligand were effective at initiating the polymerization of ε-caprolactone, but did not control the polymerizations, whereas the bis(ligand) complexes produced no polymer. These catalysts were effective at controlling the polymerization of rac-lactide. Coordinatively saturated complexes inhibit the polymerization, while initiation from either the amido or ligand alkoxide functionalities produces poly(lactic acid) with low polydispersities.

A Recommender System for Inverse Design of Polycarbonates and Polyesters

2020 ◽  
Author(s):  
Nathaniel Park ◽  
Dmitry Yu. Zubarev ◽  
James L. Hedrick ◽  
Vivien Kiyek ◽  
Christiaan Corbet ◽  
...  
Keyword(s):  
Ring Opening ◽  
High Performance ◽  
Recommendation System ◽  
Polymeric Materials ◽  
Monomer Conversion ◽  
Design Strategy ◽  
Ring Opening Polymerization ◽  
Inverse Design ◽  
False Negatives ◽  
Accelerate Development

The convergence of artificial intelligence and machine learning with material science holds significant promise to rapidly accelerate development timelines of new high-performance polymeric materials. Within this context, we report an inverse design strategy for polycarbonate and polyester discovery based on a recommendation system that proposes polymerization experiments that are likely to produce materials with targeted properties. Following recommendations of the system driven by the historical ring-opening polymerization results, we carried out experiments targeting specific ranges of monomer conversion and dispersity of the polymers obtained from cyclic lactones and carbonates. The results of the experiments were in close agreement with the recommendation targets with few false negatives or positives obtained for each class.<br>

scholarly journals Synthesis and Characterization of Polyphosphazenes Modified with Hydroxyethyl Methacrylate and Lactic Acid

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Room Temperature ◽  
Block Structure ◽  
Ring Opening Polymerization ◽  
Synthesis And Characterization ◽  
Poly Lactic Acid ◽  
Hydroxyethyl Methacrylate ◽  
H Nmr

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.

scholarly journals End Functionalization by Ring Opening Polymerization: Influence of Reaction Conditions on the Synthesis of End Functionalized Poly(lactic Acid)

2017 ◽  
Author(s):  
Luis Icart ◽  
Edson Fernandes ◽  
Lissette Agüero ◽  
Maelia Cuesta ◽  
Dionisio Silva ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid ◽  
Reaction Conditions

scholarly journals Elucidating a Unified Mechanistic Scheme for the DBU-Catalyzed Ring-Opening Polymerization of Lactide to Poly(lactic acid)

2016 ◽  
Vol 49 (13) ◽  
pp. 4699-4713 ◽  
Author(s):  
Nicholas J. Sherck ◽  
Hyun Chang Kim ◽  
You-Yeon Won
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid

Surface-Modified Cellulose Nanofibers-graft-poly(lactic acid)s Made by Ring-Opening Polymerization of l-Lactide

2019 ◽  
Vol 27 (4) ◽  
pp. 847-861 ◽  
Author(s):  
Chaniga Chuensangjun ◽  
Kyohei Kanomata ◽  
Takuya Kitaoka ◽  
Yusuf Chisti ◽  
Sarote Sirisansaneeyakul
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Cellulose Nanofibers ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid ◽  
Surface Modified ◽  
Modified Cellulose

Preparation of Anti-Fouling Poly(Lactic Acid)(PLA) Hollow Fiber Membranes via Non-Solvent Induced Phase Separation

2014 ◽  
Vol 884-885 ◽  
pp. 112-116
Author(s):  
Peng Shen ◽  
Kai Tu ◽  
Chang Yu Yang ◽  
Jian Li ◽  
Ru Xu Du
Keyword(s):  
Contact Angle ◽  
Lactic Acid ◽  
Phase Separation ◽  
Block Copolymer ◽  
Water Permeability ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Hollow Fibers ◽  
Poly Lactic Acid ◽  
Bsa Rejection

Anti-fouling PLA hollow fibers were fabricated using synthesized PLA-PEG-PLA copolymer as an additive to improve the hydrophilicity. The tri-block copolymer was prepared by ring-opening polymerization and a hydrophilic copolymer processing good compatibility with PLA molecule was obtained and utilized to fabricate membrane with PLA by NIPS. Elemental analysis showed that PLA-PEG-PLA could stably exist in membranes and endow the membrane with persistent hydrophilic. Thus the contact angle decreased nearly 20o with 5% PLA-PEG-PLA content, resulting in higher water permeability and BSA rejection which indicated the anti-fouling property of PLA membrane was improved.

scholarly journals Newly Developed Techniques on Polycondensation, Ring-Opening Polymerization and Polymer Modification: Focus on Poly(Lactic Acid)

Materials ◽  
2016 ◽  
Vol 9 (3) ◽  
pp. 133 ◽  
Author(s):  
Yunzi Hu ◽  
Walid Daoud ◽  
Kevin Cheuk ◽  
Carol Lin
Keyword(s):  
Lactic Acid ◽  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Poly Lactic Acid ◽  
Polymer Modification

scholarly journals Macromolecular Dyes by Chromophore-Initiated Ring Opening Polymerization of L-Lactide

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1979
Author(s):  
Francesca Cicogna ◽  
Guido Giachi ◽  
Luca Rosi ◽  
Elisa Passaglia ◽  
Serena Coiai ◽  
...  
Keyword(s):  
Ring Opening ◽  
Solid Phase ◽  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Ring Opening Polymerization ◽  
Polymerization Process ◽  
Polymerization Reaction ◽  
Poly Lactic Acid ◽  
Electromagnetic Spectrum ◽  
Visible Part

End functionalized polylactides are prepared by ring opening polymerization of L-lactide in the presence of stannous octoate (Sn(Oct)2). Three chromophores, 9H-carbazol-ethanol (CA), 9-fluorenyl-methanol (FM), and 2-(4-(2-chloro-4-nitrophenylazo)-N-ethylphenylamino)ethanol (Disperse Red 13, DR), are for the first time used as co-initiators in the polymerization process. The polymerization reaction is initiated by conventional thermal treatment, but in the case of FM, microwave-assisted polymerization is also carried out. CA and FM absorb and emit in the UV portion of the electromagnetic spectrum, whereas DR absorbs in the visible part. The obtained end-capped polylactides derivatives show the same photophysical properties as the initiator, so they are “macromolecular dyes” (MDs) that can be used “as synthesized” or can be blended with commercial poly(lactic acid) (PLA). The blends of PLA with MDs have ultraviolet-visible (UV-Vis) absorption and fluorescence emission features similar to that of MDs and thermal properties typical of PLA. Finally, migration tests, carried out onto the blends of PLA with MDs and PLA with free chromophores, show that MDs are less released than free chromophores both in solution and in the solid phase.

scholarly journals Microwave energy assisted synthesis of poly lactic acid via continuous reactive extrusion: modelling of reaction kinetics

RSC Advances ◽  
2017 ◽  
Vol 7 (30) ◽  
pp. 18529-18538 ◽  
Author(s):  
Satya P. Dubey ◽  
Hrushikesh A. Abhyankar ◽  
Veronica Marchante ◽  
James L. Brighton ◽  
Björn Bergmann ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Reaction Kinetics ◽  
Ring Opening ◽  
Bimetallic Catalyst ◽  
Batch Process ◽  
Reactive Extrusion ◽  
Ring Opening Polymerization ◽  
Microwave Energy ◽  
Poly Lactic Acid ◽  
Organic Catalysts

The most commonly used batch process to manufacture PLA is ring opening polymerization (ROP) of lactide monomer in a suitable solvent, in the presence of a metallic/bimetallic catalyst (Sn, Zn, and Al) or other organic catalysts.

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