Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 30 for “"polyethers"”.
-
Interaction of Metal Salts with Polyethers
The dielectric properties of pure low to medium molecular weight poly(ethylene glycol) and poly(propylene glycol) and a variety of their salt complexes have been studied through the measurement of the dielectric permittivity and dielectric loss over a range of frequency and temperature. The major …
-
Hydrogels containing linear and cyclic polyethers
… hydrogels containing both cyclic and linear polyethers have been synthesised and are described in this thesis. Initially, cyclic polyethers were occluded within the polymer matrix and the transport properties investigated. The results indicated that the presence of an ionophore can be used to …
-
Synthesis and characterization of thermo-responsive polyethers
Hyaluronic acid (HA) hydrogels are interesting biomaterials for drug delivery and tissue engineering applications. Glycidyl ether derivatives have gained much interests due to their thermo-responsive properties. Thermo-responsive random copolymers of glycidyl methyl ether (GME) and epoxyhexane (EH) …
-
Routes to complexes of open chain polyethers
The open chain polyethers, 1-(o-carboxymethoxyphenoxy)-2-(ohydroxyphenoxy) ethane HL(A), HL(B), and the diol were prepared and characterised by m.pt. and IR and 1H NMR spectroscopies. In order to determine whether the ions other than Co(II) or Zn(ll) can form complexes of type [M(M'L2)2 (M = …
-
Synthesis and characterization of polymacromonomers based on polyethers
The synthesis and polymerization of macromonomers containing a polymerizable styrene head group and a tail of ethylene oxide derivatives of different character were investigated. The synthesis of macromonomers was based on living anionic polymerization of oxiranes. Two monomers were used: …
-
Synthesis and Characterization of Novel Polyethers and Polydimethylsiloxanes for Use in Biomaterials
This dissertation focuses on the use of novel polyethers and polydimethylsiloxanes in the stabilization of magnetite nanoparticles as well as biomedical applications. The colloidal stabilities of magnetite nanoparticles coated with polyethers containing various functional endgroups were studied. …
-
Analysis of Alcohol and Alkylphenol Polyethers via Packed Column Supercritical Fluid Chromatography
Alkylphenol ethoxylates (APEOs), alcohol ethoxylates (AEOs), and alcohol propoxylates (APOs) are non-ionic surfactants used in daily care products and detergents. They are formed as an oligomeric series with a varying distribution, which determines their commercial application. The goal of the …
-
Synthesis and Characterization of Novel Polyethers and Polypeptides for Use in Biomedicine and Magnetic Resonance Imaging
… vinyl groups. A series of amphiphilic block copolyethers based on poly(ethylene oxide) and poly(1,2-butylene oxide) that incorporate VSiGE or EVGE were synthesized and characterized. The vinyl ether and vinyl silane functional groups were functionalized after polymerization and the functional …
-
Synthesis and Characterization of Well-Defined Heterobifunctional Polyethers for Coating Magnetite and Their Applications in Biomedicine Resonance Imaging
Well-defined heterobifunctional homopolyethers and amphiphilic block copolyethers containing a variety of functionalities were designed, synthesized, and characterized via GPC and 1H NMR. These have included controlled molecular weight cholesterol-PEO-OH, mono- and trivinylsilyl-PEO-OH, …
-
Fluorine-Containing Poly(aryl ethers)
… trifluoromethyl and aryl fluoride. Several polyethers were synthesized using the Williamson synthesis. Diphenols of varied fluorine and ether content were reacted with decafluorobiphenyl to form linear poly(ary! ethers) in yields ranging from 48 to 87%. Soluble polymers were obtained from …
-
Endo-selective epoxide-opening cascades in water
Chapter I. Introduction to the Ladder Polyethers. We introduce the bioactivity of the ladder polyether natural products and provide an overview of the puzzle that is their biogenesis. Cascades of endo-selective epoxide opening inspired by the biosynthetic proposal and promoted by simple neutral …
-
Structure-property relations in liquid crystalline and thermoplastic polymers: Crystal structure and morphology of liquid crystalline polyethers and the interaction of creep and physical aging in a semicrystalline thermoplastic matrix composite
… of a family of aromatic-aliphatic azomethine polyethers (where the aliphatic unit was composed of CH$\sb2$ units ranging in length from n = 1, 4, 7, 8, 9 and 10) has been examined primarily by Electron microscopy(EM) and Electron diffraction(ED).
-
Cooperative Electrostatic Polymer-Antibiotic Nanoplexes
… nanoplexes, while the amphiphilic nature of the polyethers stabilize their dispersion in physiological media. The amphiphilic nature of the polyethers in the outer shell aid in interaction of the nanoplexes with extra- and intra-cellular components and help to protect the electrostatic core from …
-
Macrocyclic chemistry: Part I - Characterization of a mixed-valence di-iron complex and synthesis of a new poly-iron complex. Part II - Synthesis, characterization of new diphosphoester macrocyclic polyethers
<p>Our research involved two projects: Crown Aza and Crown ether. Crown Aza are compounds that have nitrogens as the hetero-atoms in the macrocycle. In the first aim, the 1 H NMR spectrum of strongly-coupled di-iron complexes shows 5 different conformations, but is unable to identify these …
-
Novel hydrogel polymers
… both charged monomer groups and linear polyethers have been synthesised and described. Although variations in the EWC are observed with the structure of the monomers, it was observed that the EWC increased due to the polar character of the charged monomers and the chain length and …
-
Directing group-free endo-selective epoxide-opening cascades
[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily …
-
Towards the total synthesis of gambieric acid A
… biological activities. In 1992, a new family of polyethers was discovered from the marine dinoflagellate Gambierdiscus toxicus: gambieric acids A–D, which show antifungal activity against a variety of filamentous fungi. The purpose of this thesis is to show the progress towards the synthesis of …
-
Rhodium-catalyzed epoxide-opening cascades toward brevisin and hemibrevetoxin B
… the synthesis of oxepanes and oxepanecontaining polyethers from di- and trisubstituted epoxides. Syntheses of the ABC and EF ring systems of (-)-brevisin via all endo-diepoxide-opening cascades using this method constitute a formal total synthesis and demonstrate the utility of this methodology …
-
Design and synthesis of novel hydrogels for biological applications
… properties of these copolymers containing linear polyethers were examined. It was found that the EWC was enhanced by the presence of the hydrophilic polyether chains.Results suggest that the polyether side chains express themselves at the polymer surface, thus dictating the surface properties of …
-
Studies on the total synthesis of gambierol via endo-selective epoxide-opening cascades
… by the biosynthetic hypothesis for ladder polyethers is described. Syntheses of the ABCD and FGH fragments have been completed in 29 and 3 1 steps, respectively, using water-promoted endo-selective epoxide-opening cascades to construct the poly-THP motifs. The concentration and temperature …
Page 1 of 2