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Polynuclear Titanium Complexes For The Ring Opening Polymerisation Of Lactide
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Book Synopsis Polynuclear Titanium Complexes for the Ring-opening Polymerisation of Lactide by : Jean-Marie Eugène Pascal Cols
Download or read book Polynuclear Titanium Complexes for the Ring-opening Polymerisation of Lactide written by Jean-Marie Eugène Pascal Cols and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Titanium Complexes Based on Aminodiol Ligand for Ring Opening Polymerization of Cyclic Esters by : Dakshinamoorthy Deivasagayam
Download or read book Titanium Complexes Based on Aminodiol Ligand for Ring Opening Polymerization of Cyclic Esters written by Dakshinamoorthy Deivasagayam and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of titanium isopropoxides complexes coordinated by enantiopure, racemic, meso and diastereomeric aminodiol ligands have been prepared and characterized by spectroscopic techniques. The complexes were tested as initiators for the ring opening polymerization (ROP) of cyclic esters such as L/rac-lactide, caprolactone, butyrolactone and trimethylene carbonate via coordination-insertion mechanism. In lactide polymerizations, all complexes showed significant activity both in solution at 70°C and in bulk at 130°C with a good control. The complex derived from rac-aminodiol ligand gave partially heterotactic polylactide in ROP of rac-lactide, whereas all other complexes yielded atactic polylactides. For caprolactone polymerizations, all complexes were found to be effective initiators under both solution and bulk conditions (up to 60% monomer conversion was reached within 10 min in bulk condition at 70°C), again with good control. Kinetic studies of ROP of lactides and caprolactone in solution conditions have been investigated and showed a first kinetic order in monomer. Significant activities were also observed for (ROP) of butyrolactone and trimethylene carbonate. Block copolymers of caprolactone and lactides were successfully synthesized with these catalytic systems by sequential polymerization techniques. The complexes were also tested as initiators for the production of random copolymers containing caprolactone and lactides and a reverse order of reactivity was observed between lactide and caprolactone compared to homopolymerization.
Book Synopsis Mono(cyclopentadienyl)titanium Complexes as Initiators for Living Ring-opening Polymerization of Lactones by : Il'ya L. Rushkin
Download or read book Mono(cyclopentadienyl)titanium Complexes as Initiators for Living Ring-opening Polymerization of Lactones written by Il'ya L. Rushkin and published by . This book was released on 1993 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis of Polymers and Copolymers of Lactide Through Titanium Initiators by :
Download or read book Synthesis of Polymers and Copolymers of Lactide Through Titanium Initiators written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research described in this thesis explored the synthesis and characterisation of biocompatible and biodegradable polymers of lactide through non-toxic titanium alkoxide initiators. The research objectives focused on the preparation of polylactides in both solvent and solventless media, to produce materials with a wide range of molecular weights. The objectives of this research were also focused on the enhancement of the flexibility of the polymer chains by synthesising random and block copolymers of lactide and e-caprolactone using Ti(O-i-Pr)4 as an initiator. This work involved extensive characterisation of the synthesised copolymers using gel permeation chromatography and 1H and 13C NMR spectroscopic analysis. Kinetic studies of the ring opening polymerisation of e-caprolactone and of the copolymerisation of lactide and e-caprolactone with Ti(O-i-Pr)4 as an initiator were also carried out. The last section of this work involved the synthesis of block and star-shaped copolymers of lactide and poly(ethylene glycol) [PEG]. The preparation of lactide/PEG block copolymers was carried out by ring opening polymerisation of L-lactide using Ti(O-i-Pr)4 as an initiator and hydroxyl-terminated PEG's with different numbers of hydroxyl groups as co-initiators both in solution and solventless media. These all-in-one polymerisations yielded the synthesis of both lactide homopolymer and lactide/PEG block copolymers. In order to selectivity synthesise copolymers of lactide and PEG, the experiment was carried out in two steps. The first step consisted of the synthesis of a titanium macro-initiator by exchanging the iso-propoxide ligands by PEG with different numbers of hydroxyl groups. The second step involved the ring opening polymerisation of lactide using the titanium macrocatalyst that was prepared as an initiator. The polymerisations were carried out in a solventless media. The synthesis of lactide/PEG copolymers using polyethylene glycol with amino terminal groups was also discussed.
Book Synopsis Improvement in Titanium Complexes Supported by Schiff Bases in Ring-opening Polymerization of Cyclic Esters: ONO-tridentate Schiff Bases by :
Download or read book Improvement in Titanium Complexes Supported by Schiff Bases in Ring-opening Polymerization of Cyclic Esters: ONO-tridentate Schiff Bases written by and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Ring Opening Metathesis Polymerisation and Related Chemistry by : Ezat Khosravi
Download or read book Ring Opening Metathesis Polymerisation and Related Chemistry written by Ezat Khosravi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the last ASI in Turkey in Sept. 1995, the olefin metathesis has made remarkable strong developments with an incredible speed in various directions. New catalyst systems have been developed which have resulted in the synthesis of novel materials. Other fascinating developments have been the new catalysts for stereoselective metathesis and catalysts with considerable functional group tolerance. These new catalysts in addition to Ring Opening Metathesis Polymerisation (ROMP) and Acyclic Diene Metathesis (ADMET) are now powerful tools for Ring Closing Metathesis (RCM) and have found many applications in the synthesis of natural products. A lot of information has been established about all aspects of the olefin metathesis and there is a vast literature concerning the process, covering the initiators, mechanistic features and applications of this reaction in organic and polymer synthesis. The NATO ASI on rd th ROMP and Related Chemistry took place in Polanica-Zdroj, Poland during 3 to 15 Sept. 2000, to highlight the developments in this area and to discuss the prospects and visions for the year 2000 and beyond. The aims of the ASI were: to provide a platform for dissemination of knowledge; to promote communication between people who have a serious interest in this field of chemistry; to help establishing international scientific contacts and to provide an opportunity for the scientists with an appropriate scientific background to learn of recent developments in this field of science. There were 15 lecturers and 67 participants in this NATO ASI.
Book Synopsis Stereoselective Ring-opening Polymerization of Lactide with Aluminum Alkoxide Complexes by : Tina Marie Ovitt
Download or read book Stereoselective Ring-opening Polymerization of Lactide with Aluminum Alkoxide Complexes written by Tina Marie Ovitt and published by . This book was released on 2001 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Synthesis of Scandium and Gallium Metal Complexes for Use in the Ring-opening Polymerization of Lactide and Propylene Oxide by : Melanie Butler
Download or read book Synthesis of Scandium and Gallium Metal Complexes for Use in the Ring-opening Polymerization of Lactide and Propylene Oxide written by Melanie Butler and published by . This book was released on 2011 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: As the demand for polymers increases, it is becoming clear that the current methods used to produce polymers and the types of polymers manufactured are not sustainable. Currently, about 99% of plastics produced worldwide are made from petroleum sources. Thus the development of polymers from renewable resources such as biomass and carbon dioxide is increasingly attractive. This project investigates the efficacy of scandium and gallium complexes of tetraphenylporphyrin (TPP) and Jacobsen's ligand (salen) in the polymerization of lactide and the copolymerization of CO2 and propylene oxide. Thus far (TPP)ScCl, (TPP)GaCl, (salen)ScCl, and (salen)GaCl have been synthesized. These compounds were synthesized from the metal chlorides and protonated ligands using standard Schlenk-line and dry box techniques. Preliminary results show that these complexes are inactive in the homopolymerizations of lactide and propylene oxide. This is likely due to the low nucleophilicity of the chloride anion, which makes it a poor initiator for ring-opening polymerizations. Currently attempts to synthesize the alkoxide derivatives of these compounds are in progress.
Book Synopsis New Group 3 Organometallic Complexes for Ring-opening Polymerization of Lactones and Lactide by : Abderrahmane Amgoune
Download or read book New Group 3 Organometallic Complexes for Ring-opening Polymerization of Lactones and Lactide written by Abderrahmane Amgoune and published by . This book was released on 2006 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Des familles de complexes alcoxy-amino-bis(phénolate) (ONNO) et bis(oxazoline) du groupe 3 ont été synthétisés et caractérisés par RMN et par diffraction des Rayons X. Le comportement de ces complexes en polymérisation du rac-lactide et de la rac-[beta]-butyrolactone a été étudié. Les complexes ONNO du groupe 3 ont démontré un bon contrôle et une très haute sélectivité pour la production de PLA hautement hétérotactique (90 %) et de PHB hautement syndiotactique (94 %). L'influence de la structure de ces complexes sur l'activité et la sélectivité de la polymérisation a pu être mise en évidence. D'autre part, les complexes BOX ont démontré une activité et une productivité très intéressante pour la polymérisation du rac-lactide.Une partie de ce travail a été consacré à l'utilisation de ces complexes pour la préparation de nouveaux copolymères diblocs stéréocontrôlés, dans lesquels nous avons étudié l'organisation des molécules à l'état solide et en solution.
Book Synopsis The Catalytic Applications of Titanium Complexes in Epoxide/anhydride Ring Opening Copolymerization and Umpolung Cross-coupling Reactions by : Sahar Al Fayez
Download or read book The Catalytic Applications of Titanium Complexes in Epoxide/anhydride Ring Opening Copolymerization and Umpolung Cross-coupling Reactions written by Sahar Al Fayez and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Mono- and Multi-metallic Main Group Salen Complexes by : Anand Jay Gaston
Download or read book Mono- and Multi-metallic Main Group Salen Complexes written by Anand Jay Gaston and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Single Site Metal Catalysts for Ring Opening Polymerization of Lactides by : Carla Natalia Ayala Castro
Download or read book Single Site Metal Catalysts for Ring Opening Polymerization of Lactides written by Carla Natalia Ayala Castro and published by . This book was released on 2006 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Polymers derived from lactide (L, rae and meso) are currently finding numerous applications as biodegradable and biocompatible packaging materials for bulk commodities and drug delivery agents. The physical properties of the polymer much as the rate of hydrolysis, which forms a mechanism for time release of drugs, are dependent upon the microstructure of the polymer. Single-site metal alkoxide catalysts of the form LM(OR) where L = a [beta]-diiminate ligand and M Mg or Zn have proved effective in stereoselective ring opening polymerizations. To this end a new series of compounds LMX have been prepared where L = CH(C[t]BuNC6H3-2,6-[i]Pr2)2, M = Mg, Zn and Sn, and X a potential initiator for ring opening polymerizations of lactide i.e. an amide or alkoxide. A comparison is made with the previously reported complexes where L = CH(CMeNC6H3-2,6-[i]Pr2)2, M=Mg, Zn and Sn, and X=a potential initiator for ring opening polymerizations of lactide i.e. an amide or alkoxide. A comparison is made with the previously reported complexes where L=CH(CMeNC6H3-2,6-[i]Pr2)2.
Book Synopsis Synthesis of New Titanium Complexes Bearing a Bidentate Monoanionic Inversely-Polarized Phosphaalkene-Enolate Ligand and Their Activity in Olefin Polymerization by : Matthew Alexander Wiebe
Download or read book Synthesis of New Titanium Complexes Bearing a Bidentate Monoanionic Inversely-Polarized Phosphaalkene-Enolate Ligand and Their Activity in Olefin Polymerization written by Matthew Alexander Wiebe and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The synthesis and characterization of several inversely-polarized phosphaalkenes, including the first ring-expanded inversely-polarized hydrido-phosphaalkene and imidazolidine-based inversely-polarized phosphaalkene-enolate ligand precursors, are herein reported. Coordination of the imidazolidine-based ligands to titanium was studied. Minimal decomposition (6%) of the isolated complex occurred over several days at 60 C. The titanium complexes were explored computationally where it was revealed that there is evidence for the phosphorus atom of the bound ligand to donate an additional pair of electrons to Ti, resulting in a large stabilization of 18.2 kcal mol1. Furthermore, the titanium complex has activity up to 5.64 kgPE mol1Ti h1 in the polymerization of ethylene with little decomposition of the active species over several hours. The polymer produced was high-density polyethylene with an average molecular weight of 17.6 kDa and a Tm of 131 C.
Book Synopsis Ring-opening Polymerisation of Lactide and Other Related Monomers by : Lois Manton
Download or read book Ring-opening Polymerisation of Lactide and Other Related Monomers written by Lois Manton and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards by :
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2006 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Comprehensive Coordination Chemistry II by : J. A. McCleverty
Download or read book Comprehensive Coordination Chemistry II written by J. A. McCleverty and published by Elsevier Science. This book was released on 2003-12-17 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Coordination Chemistry II (CCC II) is the sequel to what has become a classic in the field, Comprehensive Coordination Chemistry, published in 1987. CCC II builds on the first and surveys new developments authoritatively in over 200 newly comissioned chapters, with an emphasis on current trends in biology, materials science and other areas of contemporary scientific interest.
Download or read book Biopolyesters written by Wolfgang Babel and published by Springer. This book was released on 2003-07-01 with total page 345 pages. Available in PDF, EPUB and Kindle. Book excerpt: Living systems synthesize seven different classes of polymers. They provide structure and form for cells and organisms, function as catalysts and energy storage and carry the genetic information. All these polymers possess technically interesting properties. Some of these biopolymers are already used commercially. This special volume of Advances in Biochemical Engineering/Biotechnology comprises 10 chapters. It gives an overview of the water insoluble biopolyesters, in particular of the microbially synthesized poly-hydroxyalkanoate (PHA) family. It reports the state of the art of metabolism, regulation and genetic background, the latest advances made in genetic optimization of bacteria, "construction" of transgenic plants and in vitro synthesis by means of purified enzymes. Furthermore, it describes relevant technologies and evaluates perspectives concerning increasing the economic viability and competitiveness of PHA and discusses applications in medicine, packaging, food and other fields.
