Download or read book Synthesis of Chromium III Carboxylate Complexes and Their Use in Ziegler natta Polymerization written by Mougang Djanteng Soume Berline Beatrice and published by . This book was released on 2009 with total page 380 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Syntheses of Some Chromium III Carboxylates and the Use of These Complexes as Ziegler natta Catalysts for the Polymerization of Ethylene written by Aishah Mohamed Jelan and published by . This book was released on 1995 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Use of Trinuclear Chromium III Complexes as Ziegler Natta Catalysts for the Polymerization of Ethylene written by Chui Ping Ooi and published by . This book was released on 1996 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Chromium III Acetate and Chloroacetate Complexes and Their Application in Olefin Polymerization written by Saw Hong Tan and published by . This book was released on 2007 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Chromium based Ziegler Natta Catalysts and Thier Application in Ethylene Polymerization and Copolymerization written by Jun Xuan Wong and published by . This book was released on 2010 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Chromium Guanidinate Complexes and Their Activity in Ethylene Oligomerization polymerization written by Steven Horvath and published by . This book was released on 2010 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Amine bis phenolate Complexes of Chromium for Carbon Dioxide cyclohexene Oxide Copolymerization and Group I and II Complexes for the Ring Opening Polymerization of Rac lactide written by Katalin Devaine-Pressing and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Finding novel methods for polymer synthesis has been of particular interest as of late from both a chemical and commercial standpoint. This focus stems from the recognized need for biodegradable and biocompatible polymers, originating from renewable resources, and is a legitimate endeavor by society to ease the burden imposed on the environment. Society's conscience also recognizes the great need to utilize the carbon dioxide that is released in the atmosphere and it continues to make noble efforts in order not to contribute further to the greenhouse effect caused by greenhouse gases such as carbon dioxide. Therefore, the use of carbon dioxide as a starting material and the incorporation of it in the product of a chemical synthesis are currently developing research areas. Accordingly, combining the aim of environmentally friendly polycarbonate synthesis with incorporation of carbon dioxide in the polymer chain was the goal of the research conducted in the first part of this thesis. Additionally, biodegradable and biocompatible polylactide from lactide, originating from renewable feedstocks, was produced by biocompatible complexes in the second part. Polycarbonate synthesis was carried out in the presence of novel chromium(III) catalysts which were synthesized via salt metathesis reactions from tetradentate tripodal amine-bis(phenol) ligands. The complexes were characterized by MALDI-TOF mass spectrometry, UV-Vis and IR spectroscopy, magnetic susceptibility measurement and elemental analysis. The catalyst precursors selectively produced polycarbonates from epoxides and carbon dioxide with high yields and moderate molecular weights. Mechanistic studies revealed a first order dependence on catalyst concentration and that ring opening of the epoxide was initiated by a nucleophilic species originating either from the complex or from an externally added nucleophile. Biocompatible magnesium-, lithium-, sodium-, potassium- and calcium complexes of an amino-bis(phenolato) ligand were also prepared and characterized for the synthesis of polylactide, a biodegradable and biocompatible polymer. The magnesium and the sodium complexes in particular showed high catalytic activity and good control over the reaction. The complexes were active even under relatively low catalyst loading (0.1 - 0.2 mol%) and produced polymers of high purity as revealed by NMR, DSC and TGA.
Download or read book Synthesis of Chromium Guanidinate Complexes and Their Activity in Ethylene Oligomerization polymerization written by Steven Horvath and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterisation of Chromium III Complexes with Polypyridyl Ligands written by Jonas Michael Schönle and published by . This book was released on 2014 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Reactions of Chromium III amide Complexes in Non aqueous Media written by James Richard Lindsay and published by . This book was released on 1965 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Chromium III Complexes written by Chana Ngoc Wong and published by . This book was released on 2003 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis of Chromium III Complexes with Nucleotide Amino Acid and Peptide written by Weiqing Weng and published by . This book was released on 1987 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Novel Chromium III Complexes for Use as DNA Photocleavage Agents written by David Christopher Sibley and published by . This book was released on 2008 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Spectroscopic Studies of Chromium III Amino Acid Complexes written by Ahmad Rostam-Kolayi and published by . This book was released on 1974 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis Characterization and Catalytic Activity of Chromium Complexes written by Joanna Gurnham and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been a growing demand for specific linear alpha olefins in the polyethylene industry in order to control polymer rheology. This growing demand thereby increases the need for highly active and selective ethylene oligomerization catalysts. Chromium-based catalysts continue to be of high interest for this application due to this metal's versatility in both selective and non selective ethylene oligomerization. Ligand design is an important consideration in oligomerization chemistry: the ability of the ligand to stabilize low valent chromium and to support a two-electron redox process will allow the catalytic systems to follow the selective ring expansion mechanism for oligomerization. Chelating aminophosphane based ligands, previously studied by our group, have been shown to support both tri- and tetramerization of ethylene. We have explored modifications of one of the NP arms by replacing with a different coordinating group in an attempt to further stabilize the monovalent state of chromium and increase selectivity. Other ligands explored in this work are pyrrole based ligands, which have shown high activity and selectivity towards ethylene oligomerization. One example of this is the commercial Chevron-Phillips system. Recently, the co-polymerization of CO2 with epoxides has been studied as an environmentally friendly route to convert CO2 into biodegradable polymers. The first successful catalytic system to achieve these results consisted of a diethyl-zinc complex. More recently, aluminum, chromium, cadmium and cobalt have been studied as polycarbonate catalysts. To date, the only reported chromium catalysts for CO2-epoxide copolymerization are Cr-salen and Cr-porphyrin complexes, studied by Darrensbourg and Holmes, respectively. We were particularly interested in finding new chromium-based complexes able to catalyze epoxide/CO2 copolymerization by using molecules with the nitrogen donor motif embedded in different functions such as neutral pyridines with anionic pendants, pyrroles with either imine or amine pendants, or a combination of these.
Download or read book Synthesis and Reactions of Some Chromium III Ammine Complexes written by Margaret Anne Cavanaugh and published by . This book was released on 1973 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt:
