Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Zinc And Zirconium Catalysts In Rac Lactide Polymerization
Download Zinc And Zirconium Catalysts In Rac Lactide Polymerization full books in PDF, epub, and Kindle. Read online Zinc And Zirconium Catalysts In Rac Lactide Polymerization ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Zinc and Zirconium Catalysts in Rac-lactide Polymerization by : Fatemeh Dordahan
Download or read book Zinc and Zirconium Catalysts in Rac-lactide Polymerization written by Fatemeh Dordahan and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The phenoxy-imine ligand bearing heteroatom-containing N and O were prepared from condensation of paraformaldehyde, 4-(tert-butyl)-2-tritylphenol with di-(2-picolyl)amine. LZnN(SiMe3)2 was prepared by reaction of Zn(N(SiMe3)2)2 and the ligand. The complex has been studied by X-ray diffraction and NMR. Application of this complex in rac-lactide polymerization gave atactic PLA via a catalytic-site mediated chain-end control mechanism. Pyridylaminophenol ligands were prepared from phenol (2,4-di-tert-butylphenol, 2,4-di-cholorolphenol, 2,4-di-methylphenol), pyridine-2-ylmethylamine and formaldehyde (LH2 = (2,4-X2C6(OH)H2(5-CH2)2N(CH2C5H4N), X = Me or Cl). Reaction of Zr(OnPr)4 with 2 equiv of LH2 gave L2Zr. L2Zr were mixtures of C2-symmetric isomers, which was confirmed by NMR, DFT and X-ray diffraction studies. The only isomer for X=Me was the cis-isomer while the major isomer for X=Cl was the trans-isomer. All complex were active in rac-lactide polymerization at 140 °C and heterotactic PLA was obtained. L2Zr followed an activated monomer mechanism with benzyl alcohol as co-initiator.
Book Synopsis Manganese, Copper and Zinc Catalysts in Rac-lactide Polymerization by : Pargol Daneshmandkashani
Download or read book Manganese, Copper and Zinc Catalysts in Rac-lactide Polymerization written by Pargol Daneshmandkashani and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis New High-activity Zinc(II)-based Catalysts for Ring-opening Polymerization by : Ming Cheng
Download or read book New High-activity Zinc(II)-based Catalysts for Ring-opening Polymerization written by Ming Cheng and published by . This book was released on 2000 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Studies of Single-site Zinc, Magnesium and Calcium Catalyst Precursors for Ring-Opening Polymerization of Lactides by : Khamphee Phomphrai
Download or read book Studies of Single-site Zinc, Magnesium and Calcium Catalyst Precursors for Ring-Opening Polymerization of Lactides written by Khamphee Phomphrai and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The preparation and characterization of a series of closely related magnesium and zinc compounds active for ROP of lactides are reported using three [beta]-diiminate ligands L 1, L 2 and L 3 where L 1 = CH(CMeNC 6 H 3 -2,6- i Pr 2) 2, L 2 = CH(CMeNC 6 H 4 -2- t Bu) 2 and L 3 = CH(CMeNC 6 H 4 -2-OMe) 2 . For the L 1 ligand, L 1 Mg(N i Pr 2)·(THF), L 1 Zn(N i Pr 2), L 1 Mg(O t Bu)·(THF), L 1 Zn(O t Bu) and L 1 Zn(OSiPh 3)·(THF) have been synthesized. All compounds initiate and sustain ROP of lactides. For a related series L 1 MX(THF) n, where n = 0 or 1, the reactivity follows the order M = Mg> Zn and X = O t Bu> N i Pr 2> N(SiMe 3) 2> OSiPh 3 . Heterotactic polylactide (PLA) is produced from ROP of rac-lactide by zinc catalysts in CH 2 Cl 2 . Magnesium catalysts produce atactic and heterotactic PLA in CH 2 Cl 2 and THF, respectively. The resting states for Zn and Mg are proposed to be L 1 Zn(nu 2 -OCHMeC(O)OP) and L 1 Mg(mu-OP) 2 MgL 1 . For the L 2 ligand, L 2 MgN i Pr 2 ·(THF) and L 2 ZnN i Pr 2 are prepared. In solution, L 2 ZnN i Pr 2 exists as a mixture of syn- and anti-rotamers while L 2 MgN i Pr 2 ·(THF) exists only as a syn-rotamer. In the zinc compound, the syn-conformer is shown to be more reactive than the anti-conformer and is responsible for the polymerization. Heterotactic PLA is obtained in CH 2 Cl 2 for the zinc compound and in THF for the magnesium compound. For the L 3 ligand, L 3 MgN(SiMe 3) 2, [L 3 MgO t Bu] 2, L 3 ZnN(SiMe 3) 2, L 3 ZnO i Pr and L 3 CaN(SiMe 3) 2 ·(THF) are prepared. The OMe groups of ligand L 3 show little affinity toward zinc and in the ROP of rac-lactide give PLA with only moderately enhanced heterotactic tetrads. The OMe groups are shown to bind to Mg reversibly and display significant enhancement of heterotactic PLA. The first single-site calcium complexes of L 1 and tris(pyrazolyl/indazolyl)borate ligands are reported and shown to initiate and sustain ROP of lactide: L 1 CaNR 1 2 ·(THF), Tp R2 CaNR 1 2 ·(THF) n, Tp Men CaNR 1 2, (9-BBN)Bp (+)-Cam CaNR 1 2 ·2THF where Tp R2 = [nu 3 -HB(3-R 2 pz) 3], R 1 = SiMe 3, R 2 = t Bu or i Pr, n = 0 or 1, Men = menthone-derived indazole and Cam = camphor-derived indazole. All calcium complexes polymerize rac-lactide in THF giving mostly atactic PLA except for Tp tBu CaNR 1 2 where heterotactic PLA is produced. Tp tBu CaNR 1 2 reacts with 2,6-diisopropylphenol giving Tp tBu Ca(O-2,6- i Pr 2 C 6 H 3). The order of heterotactic selectivity is THF> PO approx CHO> CH 2 Cl 2 . The single-site calcium complexes are not active for ROP of epoxides and the compound Tp tBu Ca(O-2,6- i Pr 2 C 6 H 3)·(PO) is reported and structurally characterized by a single crystal X-ray diffraction study.
Book Synopsis Synthesis, Characterization and Catalytic Activity Study of Zinc Aminobis(phenolate) Complexes Towards Ring-opening Polymerization of Rac-lactide by : Yi Liu
Download or read book Synthesis, Characterization and Catalytic Activity Study of Zinc Aminobis(phenolate) Complexes Towards Ring-opening Polymerization of Rac-lactide written by Yi Liu and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of bimetallic and trimetallic zinc complexes of amino-bis(phenolato) ligands was synthesized and characterized. Bimetallic complexes (ZnEt)2[L1] (1a) and (ZnEt)2[L2] (1b) (where [L1] = n-propylamine-N,N-bis(2-methylene-4,6-di-t-butylphenolate) and [L2] = n-propylamine-N,N-bis(2-methylene-6-t-butyl-4-methylphenolate) were prepared via reaction of the proligands H2[L1] and H2[L2] with ZnEt2 in pentane. A THF adduct (ZnEt)2[L1]·THF (1a·THF) was obtained by using THF as solvent. Treatment of 1a with one or two equiv. of isopropyl alcohol gave a trimetallic zinc complex Zn3(i-PrO)2[L1]2 (2). The catalytic activities of these complexes towards ring-opening polymerization (ROP) of rac-lactide were studied in the absence and presence of benzyl alcohol or isopropyl alcohol. These complexes exhibit moderate to good activity for ROP of rac-lactide both in the melt phase and solution. The influence of catalyst and co-initiator loading were studied and thermodynamic activation parameters were determined. Characterization of the polymers by GPC and MALDI-TOF MS showed controlled and living polymerizations for rac-lactide in the presence of alcohol.
Book Synopsis Synthesis, Structure and Properties of Poly(lactic acid) by : Maria Laura Di Lorenzo
Download or read book Synthesis, Structure and Properties of Poly(lactic acid) written by Maria Laura Di Lorenzo and published by Springer. This book was released on 2017-10-20 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Advances in Polymer Science presents critical reviews of the present and future trends in polymer and biopolymer science. It covers all areas of research in polymer and biopolymer science including chemistry, physical chemistry, physics, material science.The thematic volumes are addressed to scientists, whether at universities or in industry, who wish to keep abreast of the important advances in the covered topics.Advances in Polymer Science enjoys a longstanding tradition and good reputation in its community. Each volume is dedicated to a current topic, and each review critically surveys one aspect of that topic, to place it within the context of the volume. The volumes typically summarize the significant developments of the last 5 to 10 years and discuss them critically, presenting selected examples, explaining and illustrating the important principles, and bringing together many important references of primary literature. On that basis, future research directions in the area can be discussed. Advances in Polymer Science volumes thus are important references for every polymer scientist, as well as for other scientists interested in polymer science - as an introduction to a neighboring field, or as a compilation of detailed information for the specialist.Review articles for the individual volumes are invited by the volume editors. Single contributions can be specially commissioned.Readership: Polymer scientists, or scientists in related fields interested in polymer and biopolymer science, at universities or in industry, graduate students
Book Synopsis Studies Towards Degradable Polymers by : Peter Malatji
Download or read book Studies Towards Degradable Polymers written by Peter Malatji and published by . This book was released on 2012 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Cooperative Catalysis by : René Peters
Download or read book Cooperative Catalysis written by René Peters and published by John Wiley & Sons. This book was released on 2015-04-27 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts in the field, this is a much-needed overview of the rapidly emerging field of cooperative catalysis. The authors focus on the design and development of novel high-performance catalysts for applications in organic synthesis (particularly asymmetric synthesis), covering a broad range of topics, from the latest progress in Lewis acid / Br?nsted base catalysis to e.g. metal-assisted organo catalysis, cooperative metal/enzyme catalysis, and cooperative catalysis in polymerization reactions and on solid surfaces. The chapters are classified according to the type of cooperating activating groups, and describe in detail the different strategies of cooperative activation, highlighting their respective advantages and pitfalls. As a result, readers will learn about the different concepts of cooperative catalysis, their corresponding modes of operation and their applications, thus helping to find a solution to a specific synthetic catalysis problem.
Book Synopsis The Development of Cationic Zinc Complexes as a New Class of Lactide Polymerization Catalyst by : Craig Andrew Wheaton
Download or read book The Development of Cationic Zinc Complexes as a New Class of Lactide Polymerization Catalyst written by Craig Andrew Wheaton and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Guanidines as Reagents and Catalysts II by : Philipp Selig
Download or read book Guanidines as Reagents and Catalysts II written by Philipp Selig and published by Springer. This book was released on 2017-04-12 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Topics in Heterocyclic Chemistry presents critical reviews on present and future trends in the research of heterocyclic compounds. Overall the scope is to cover topics dealing with all areas within heterocyclic chemistry, both experimental and theoretical, of interest to the general heterocyclic chemistry community. The series consists of topic related volumes edited by renowned editors with contributions of experts in the field. All chapters from Topics in Heterocyclic Chemistry are published Online First with an individual DOI. In references, Topics in Heterocyclic Chemistry is abbreviated as Top Heterocycl Chem and cited as a journal
Book Synopsis Synthetic Biodegradable Polymers by : Bernhard Rieger
Download or read book Synthetic Biodegradable Polymers written by Bernhard Rieger and published by Springer Science & Business Media. This book was released on 2012-01-29 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: Salen Metal Complexes as Catalysts for the Synthesis of Polycarbonates from Cyclic Ethers and Carbon Dioxide, by Donald J. Darensbourg.- Material Properties of Poly(Propylene Carbonates), by Gerrit. A. Luinstra and Endres Borchardt.- Poly(3-Hydroxybutyrate) from Carbon Monoxide, by Robert Reichardt and Bernhard Rieger. - Ecoflex® and Ecovio®: Biodegradable, Performance-Enabling Plastics, by K. O. Siegenthaler, A. Künkel, G. Skupin and M. Yamamoto.- Biodegradability of Poly(Vinyl Acetate) and Related Polymers, by Manfred Amann and Oliver Minge.- Recent Developments in Ring-Opening Polymerization of Lactones, by P. Lecomte and C. Jérôme.- Recent Developments in Metal-Catalyzed Ring-Opening Polymerization of Lactides and Glycolides: Preparation of Polylactides, Polyglycolide, and Poly(lactide-co-glycolide), by Saikat Dutta, Wen-Chou Hung, Bor-Hunn Huang and Chu-Chieh Lin.- Bionolle (Polybutylenesuccinate), by Yasushi Ichikawa, Tatsuya Mizukoshi.- Polyurethanes from Renewable Resources, by David A. Babb.-
Book Synopsis Reactive and Functional Polymers Research Advances by : Matheus I. Barroso
Download or read book Reactive and Functional Polymers Research Advances written by Matheus I. Barroso and published by Nova Publishers. This book was released on 2008 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents research on inorganic and organic functional polymers, both solid and liquid, acting as reagents, catalysts, carriers of protecting groups, templates, ion-exchangers, selective sorbents, chelating agents, supports for enzymes and cells, and the like. This book also covers reactive crosslinkable prepolymers, and degradable polymers.
Book Synopsis Macroporous Polymers by : Bo Mattiasson
Download or read book Macroporous Polymers written by Bo Mattiasson and published by CRC Press. This book was released on 2009-12-23 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Macroporous polymers are rapidly becoming the material of choice for many tissue engineering, bioseparation, and bioprocessing applications. However, while important information is scattered about in many different publications, none, to date, have drawn this information together in user-friendly format, until now. Meeting the need for an accessibl
Book Synopsis Synthesis and Structures of Tridentate Ketoiminate Zinc Complexes Bearing Trifluoromethyl Substituents that Act as L-lactide Ring Opening Polymerization Catalysts by : Nomaan M. Rezayee
Download or read book Synthesis and Structures of Tridentate Ketoiminate Zinc Complexes Bearing Trifluoromethyl Substituents that Act as L-lactide Ring Opening Polymerization Catalysts written by Nomaan M. Rezayee and published by . This book was released on 2012 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Dinucleating Ligand Platforms Supporting Zinc and Indium Catalysts for Stereoselective Lactide Polymerization by : Alexandre Bertrand Kremer
Download or read book Dinucleating Ligand Platforms Supporting Zinc and Indium Catalysts for Stereoselective Lactide Polymerization written by Alexandre Bertrand Kremer and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Sustainable Chemistry by : Michael North
Download or read book Sustainable Chemistry written by Michael North and published by Royal Society of Chemistry. This book was released on 2016 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focussing on catalysis through non-endangered metals, this book is an important reference for researchers working in catalysis and green chemistry.
Book Synopsis Polymer Engineering by : Bartosz Tylkowski
Download or read book Polymer Engineering written by Bartosz Tylkowski and published by Walter de Gruyter GmbH & Co KG. This book was released on 2022-11-07 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymer Engineering 2nd edition book focuses on recyclability of thermosetting polymers, application of natural and synthetic polymers in fabric & home care products. The authors not only describe the latest developments in polymer chemistry for membrane technologies concerning energy production and storage systems but also for development of encapsulation technologies and separation processes.
