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Synthèse de Poly(3,4-ethylènedioxythiophène) en milieux dispersants organiquesCharba, Abdulkarim 16 December 2011 (has links)
L’objectif de ce travail de thèse était de développer des encres organiques de polymères semi-conducteurs. Il s’est ainsi agi de synthétiser des latex de poly (3,4-éthylènedioxythiophène) (PEDOT) dispersibles en milieux organiques (cyclohexane ou toluène) par polymérisation oxydative de l’EDOT en présence de stabilisant stériques et/ou électrostatiques. Le stabilisant est un polymère fonctionnalisé par une unité ou plusieurs unités fonctionnelles qui peuvent réagir avec la chaîne de PEDOT en croissance assurant ainsi des liaisons covalentes ou électrostatiques entre celui-ci et le stabilisant. La taille des particules de PEDOT est contrôlée par la masse molaire, la concentration et par la fonctionnalité du stabilisant. Le PEDOT obtenu est caractérisé par diffusion de la lumière (DLS), par microscopie électronique à balayage (MEB) microscopie électronique à transmission (TEM) et par des mesures de conductivité. / Spherical poly(3,4-ethylenedioxythiophene) nano-particles with narrow size distribution were prepared in organic dispersant media in the presence of iron(III) chloride FeCl3 or iron(III) dodecylbenzenesulfonate {Fe(DBS)3} as oxidant and a functionalized polyisoprene (ω-R-PI) as a stabilizer. Two kinds of functionalized polyisoprene were used as stabilizers. Pyrrole, fluorene, Thiophene and methylthiophene end caped polyisoprenes were used as reactive stabilizers. Lithium sulfonate end caped polyisoprene was used as steric stabilizer. The effect of the nature of the solvent, the molar mass, the concentration, and the nature of the functional end unit of the stabilizer on the size and morphology of PEDOT particles were investigated. Polyisoprenes containing sulfonate groups were also used as steric/electrostatic stabilizers. By this way, the sulfonate groups act as counter ions for oxidized PEDOT leading to electrostatic attraction between it and the stabilizer, ensuring stabilization of the latex. Four kinds of polyisoprene-based steric electrostatic stabilizers having one or many sulfonate groups were prepared: sulfonate end-capped polyisoprene (PI-SO3Li), partially sulfonated polyisoprene (PIS), polyisoprene grafted to polystyrene sulfonate (PI-g-PSS) and polyisoprene grafted to polyisoprene sulfonate (PI-g-PIS). The effects of the molar mass of the stabilizer and the sulfonate group content on the PEDOT particle morphology were studied.PEDOT samples were characterized with transmission electron microscopy (TEM), atomic force microscopy (AFM), scanning electron microscopy (SEM), dynamic light scattering (DLS) analysis and conductivity measurements.
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Ferrocene-Based Monomers, Oligomers and Polymers as Electro-Active MaterialsAl Khalyfeh, Khaled 20 December 2016 (has links)
The present PhD thesis deals with the synthesis and characterization of functionalized ferrocenes with up to four aldehyde and vinyl groups and their usage as monomers to produce novel ferrocene-based oligomers with conjugated backbones via ADMET (acyclic diene metathesis) and HWE (Horner-Wadsworth-Emmons) reaction protocols. In addition, ferrocene-containing polymers (linear, cross-linked and co-polymers) with aliphatic backbones generated by anionic bulk and solution polymerization routes, and their electrochemistry behaviors were studied. The main aspects of this work lies in the enhancement of the electrical properties of the ferrocene-based materials (oligomers or polymers) by varying the polymer backbone, providing multi-functionalities for cross-linking and co-polymerization processes and thereby increasing the molecular weight of the products, furthermore, the application as electro-active materials, especially for the charge storage purposes is discussed.
High monomer consumption, relatively high molar mass as well as longer chains were achieved by bulk protocol. Electrochemical measurements (CV) reveals that formyl-ferrocenes bearing more than two formyl functionalities are very electron poor materials and easily decomposes upon oxidation. Reducing the measurement temperature and the usage of [NnBu4][B(C6F5)4] as electrolyte allowed for reliable behavior. A linear correlation between the redox potential and the number of the formyl functionalities was found. Multicyclic measurements showed that ferrocenyl / ferrocenium redox couples in the polymeric materials are stable at least up to 100 cycles. The spectro-electrochemical studies show that the conjugated materials (oligomers) have electron transfer interactions (IVCT) through the chains, while the aliphatic backbone between the ferrocenyl units (poly vinylferrocene materials) hindered the metal-metal coupling along the chain and only a ligand-to-metal charge transfer excitation could be observed. / Die vorliegende Doktorarbeit beschäftigt sich mit Synthese und Charakterisierung von funktionalisierten Ferrocenen mit bis zu vier Aldehyd- und Vinylgruppen und ihrer Verwendung als Monomere für neuartige ferrocenbasierte Oligomere mit konjugiertem Rückgrat unter ADMET (acyclic diene metathesis) und HWE- (Horner-Wadsworth-Emmons) Reaktionsbedingungen. Zusätzlich wurden ferrocenhaltige Polymere mit einem aliphatischen Rückgrat durch Polymerisation mit und ohne Lösemittel hergestellt und ihr elektrochemisches Verhalten untersucht. Das Hauptaugenmerk dieser Arbeit liegt in der Optimierung der elektrochemischen Eigenschaften der ferrocenbasierten Materialien (Oligomere oder Polymere) durch Variation des Polymerrückgrats, welche zahlreiche funktionelle Gruppen für die vernetzte Polymerisation und die Co-Polymerisation liefert. Durch diesen Prozess wird das molekulare Gewicht erhöht. Zusätzlich wird die Verwendung als elektroaktive Materialien insbesondere für die Energiespeichertechnik diskutiert.
Durch lösungsmittelfreie Reaktionsbedingungen wurden ein hoher Monomerumsatz, relativ hohe molare Massen und zugleich längere Polymerketten erzielt. Elektrochemische Messungen (CV) zeigten, dass Ferrocenmoleküle mit mehr als zwei Formylgruppen die Elektronendichte an der Ferrocenyleinheit verringern und bei Oxidation leicht zersetzt werden. Erniedrigung der Messtemperatur und die Verwendung des nur schwach koordinierenden Leitsalzes [NnBu4][B(C6F5)4] führten zu aussagekräftigen Ergebnissen. Weiterhin konnte ein linearer Zusammenhang zwischen dem Redoxpotential und der Anzahl der Formyleinheiten aufgezeigt werden. Mutlizyklische Messungen bestätigten, dass das Ferrocen / Ferrocenium-Redoxpaar mindestens 100 Zyklen stabil ist. Mittels spektroelectrochemisches Messungen konnte gezeigt werden, dass konjungierte (oligomere) Verbindungen eine elektronische Wechselwirkung (IVCT) aufweisen, während aliphatische Rückgrade eine Wechselwirkung zwischen Ferrocen / Ferrocenium (polyvinylferrocenbasierte Materialien) verhindern und nur ein LMCT Übergang (Ligand zu Metall Charge-Transfer) beobachtet werden kann.
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Controlled Synthesis and Characterization of Branched, Functionalized, and Cyclic PolymersChavan, Vijay S. 10 August 2011 (has links)
No description available.
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Effect Of Chain End Functional And Chain Architecture On Surface SegregationZhang, Zimo January 2017 (has links)
No description available.
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Pyridine and amine functionalized polymers by anionic and controlled free radical polymerization methodsNdawuni, Mzikayise Patrick 07 1900 (has links)
The synthesis of dipyridyl functionalized polysulfones with improved hydrophilicity, enhanced membrane morphology and excellent ATRP polymeric ligand properties was conducted by the following method:
(a) the formation of lithiated polysulfone from unmodified polysulfone and the subsequent reaction with 2,2'-vinylidenedipyridine in tetrahydrofuran at -78 oC under argon atmosphere to afford the corresponding dipyridyl functionalized polysulfone. The stoichiometry of the reaction affects the degree of functionalization of the product. When equimolar amounts of 2,2'-vinylidenedipyridine are added to the lithiated polysulfone, the degree of functionalization obtained was 45%. However, the addition of 10% and 20% molar excess of 2,2'-vinylidenedipyridine to the corresponding lithiated polysulfone produced dipyridyl functionalized polysulfones with degrees of functionalization of 80% and 95%, respectively; and
(b) the membranes obtained from unmodified polysulfone as well as dipyridyl functionalized polysulfones were characterized by atomic force microscopy, scanning electron microscopy, pure water permeation measurements and contact angle measurements.
Amine chain end functionalized polystyrene and poly(methyl methacrylate) were prepared by Atom Transfer Radical Polymerization (ATRP) methods as follows:
(a) •-Aminophenyl functionalized polystyrene was prepared in quantitative yields by ATRP methods using a new primary amine functionalized initiator adduct, formed in situ by the reaction of 1-(4-aminophenyl)-1-phenylethylene and (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst in diethyl ether at 110 oC, for the polymerization of styrene.(b) New •-bis(aminophenyl) and •,ω-tetrakis(aminophenyl) functionalized polymers were prepared in quantitative yields by the ATRP method using the following synthetic strategy:
(i) the initiation of styrene polymerization with a new primary diamine functionalized initiator adduct, generated in situ by the reaction of stoichiometric amounts of 1,1-bis(4-aminophenyl)ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst, afforded •-bis(aminophenyl) functionalized polystyrene; and
(ii) •-bis(aminophenyl) functionalized poly(methyl methacrylate) was prepared by the ATRP method using the primary diamine functionalized initiator adduct as initiator for methyl methacrylate polymerization; and
(iii) well defined •,ω-tetrakis(aminophenyl) functionalized polystyrene was prepared by the post ATRP chain end modification reaction of •-bis(aminophenyl) functionalized polystyrene with 1,1-bis(4-aminophenyl)-ethylene at the completion of the polymerization reaction.
(c) Similarly, •-bis(4-dimethylaminophenyl) functionalized polystyrene was prepared by using a new tertiary diamine functionalized initiator adduct, formed in situ by treatment of equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]-ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as the catalyst in diphenyl ether at 110 oC for the initiation of styrene polymerization by the ATRP method. Furthermore, the ATRP of methyl methacrylate, initiated by the new tertiary diamine functionalized initiator adduct, produced •-bis(4-dimethylaminophenyl) functionalized poly(methyl methacrylate). In addition, •,ω-tetrakis(4-dimethylaminophenyl) functionalized polystyrene was synthesized via a post ATRP chain end modification reaction of •-bis(4-dimethylaminophenyl) functionalized polystyrene with equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]ethylene at the completion of the polymerization process.
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Quantitative yields of the different amine functionalized polymers with predictable number average molecular weights (Mn = 1.3 x 103 – 16.4 x103 g/mol), narrow molecular weight distributions (Mw/Mn = 1.03 – 1.29) and controlled chain end functionality were obtained.
Polymerization kinetics data was employed to determine the controlled/living character of each ATRP reaction leading to the formation of the different amine chain end functionalized polymers. The polymerization processes were monitored by gas chromatographic analyses. Polymerization kinetics measurements for all reactions show that the polymerizations follow first order rate kinetics with respect to monomer consumption. The number average molecular weight of the amine functionalized polymers increases linearly with percentage monomer conversion and polymers with narrow molecular weight distribution were obtained.
The ATRP of styrene, catalyzed by a novel dipyridyl functionalized polysulfone/CuBr supported catalyst system, afforded well defined polystyrene with predictable number average molecular weight and narrow molecular weight distribution in a controlled/living free radical polymerization process.
The substituted 1,1-diphenylethylene initiator precursor derivatives and the functionalized polymers were characterized by nuclear magnetic resonance spectrometry, fourier transform infrared spectroscopy, thin layer chromatography, column chromatography, size exclusion chromatography, non-aqueous titrations, differential scanning calorimetry and thermogravimetrical analysis. / Chemistry / M. Sc. (Chemistry)
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Développement de tensioactifs à base d’acides biliaires pegylés pour des applications pharmaceutiquesLe Dévédec, Frantz 03 1900 (has links)
Les acides biliaires sont reconnus comme des tensioactifs d’origine biologique
potentiellement applicables dans le domaine pharmaceutique. Leurs structures en font
une plateforme idéale pour l’obtention de nouvelles architectures polymères. Des
composés synthétisés par polymérisation anionique de dérivés d’oxirane comme
l’oxyde d’éthylène, offre des dérivés amphiphiles pegylés démontrant des propriétés
d’agrégation intéressantes en vue d’une amélioration de la biocompatibilité et de la
capacité d’encapsulation médicamenteuse. Une large gamme d’acides biliaires
pegylés (BA(EGn)x) a été préparée avec comme objectif premier leurs applications
dans la formulation de principes actifs problématiques. Pour cela, une caractérisation
rigoureuse du comportement de ces dérivés (modulation de la longueur (2 < n < 19)
et du nombre de bras (2 < x < 4) de PEG) en solution a été réalisée. Dans le but
d’améliorer la biodisponibilité de principes actifs lipophiles (cas de l’itraconazole),
des nanoémulsions spontanées, composées de BA(EGn)x et d’acide oléique, ont été
développées. L’évaluation in vitro, de la toxicité (cellulaire), et de la capacité de
solubilisation des systèmes BA(EGn)x, ainsi que les paramètres pharmacocinétiques in
vivo (chez le rat), suggèrent une livraison contrôlée par nos systèmes auto-assemblés
lors de l’administration orale et intraveineuse.
Aussi, la synthèse de copolymères en blocs en étoile à base d’acide cholique
pegylés a été effectuée par polymérisation anionique par addition d’un second bloc au
caractère hydrophobe de poly(éther d’allyle et de glycidyle) (CA(EGn-b-AGEm)4).
Selon le ratio de blocs hydrophiles-hydrophobes CA(EGn-b-AGEm)4, des réponses
thermiques en solution (LCST) ont été observées par un point de trouble (Cp) entre 8
oC et 37 oC. Un mécanisme de formation d’agrégats en plusieurs étapes est suggéré.
La thiolation des allyles des PAGE permet une fonctionnalisation terminale à haute
densité, comparable aux dendrimères. Les caractérisations physico-chimiques des
CA(EGn-b-AGEm-NH2)4 et CA(EGn-b-AGEm-COOH)4 indiquent la formation de
structures auto-assemblées en solution, sensibles à la température ou au pH. Cette
fonctionnalisation élargie le domaine d’application des dérivés d’acides biliaires
pegylés en étoile vers la transfection d’ADN, la livraison de siRNA thérapeutiques ou
encore à une sélectivité de livraison médicamenteux (ex. sensibilité au pH, greffage
ligands). / Bile acids are natural compounds and may have potential for pharmaceutical applications. Their structures provide an interesting platform for polymerization to obtain well-defined architectures. The anionic polymerization of oxirane derivatives, mainly PEG derivatives, endowed new aggregation properties and improvement of biocompatibility of the new amphiphilic polymers based on bile acids.
A library of pegylated bile acids (BA(EGn)x) was prepared for the formulation of lipophilic drugs. The aqueous physicochemical behaviors of these derivatives (modulation of the length (2 < n < 19) and the number (2 < x < 4) of PEG arm) were investigated.
In order to improve the bioavailability of insoluble active compounds (itraconazole, an antifungal drug), a binary system based on the association of BA(EGn)x and oleic acid, formed self-emulsifying drug delivery systems. The in vitro evaluation of cell toxicity and solubilization capacities of the BA(EGn)x systems followed by the in vivo evaluation in rats of the pharmacokinetic parameters demonstrated the advantages of our self-assembled system for controlled drug delivery for both oral and intravenous administration.
Star-shaped block copolymers of pegylated cholic acid (CA(EGn-b-AGEm)4) were prepared by the introduction of a second hydrophobic block of PAGE poly(allyl glycidyl ether). They demonstrated thermosensitivity (8 oC < LCST < 37 oC) in aqueous solution, suggesting a mechanism based on the formation of aggregates in two steps. The PAGE block with pendant groups may facilitate futher functionalization. The thiolation of allyl yields a new class of charged PEGylated star polymers (with multiple amines or carboxylic groups). CA(EGn-b-AGEm-NH2)4 and CA(EGn-b-AGEm-COOH)4 derivatives showed self-assembled structures in solution with temperature and pH responsiveness, respectively. This functionalization may lead to broader application of pegylated star derivatives in DNA transfection systems, siRNA delivery systems or as selective delivery system (pH-dependent).
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Activation non-métallique de la polymérisation anionique par ouverture de cycle des cyclopropane-1,1-dicarboxylates : application à la synthèse de transporteurs transmembranairesIlly, Nicolas 10 December 2009 (has links)
La base phosphazène ButP4 associée au thiophénol ou au bis (2-mercaptoéthyl) éther a été utilisée avec succès pour amorcer quantitativement la polymérisation anionique par ouverture de cycle des monomères cyclopropane-1,1-dicarboxylates de dialkyle. Pour des températures comprises entre 30 et 60°C dans le THF ou entre 30 et 100°C dans le toluéne, le mécanisme observé est celui d'une polymérisation anionique vivante qui conduit à des polymères présentant des indices de polymolécularité faibles et dont les Mn expérimentaux (mesurés par SEC et RMN 1H) sont en accord avec les valeurs théoriques. D'autres systèmes déamorçage comme le carbazole ou des composés possédant un proton acide associés à ButP4 conduisent également à des polymères bien définis. Une étude cinétique montre que l'ordre interne en monomère est égal à 1 sur l'ensemble de la gamme de conversion. Le système déamorçage thiophénol / ButP4 dans le THF présente une réactivité bien supérieure à celle du thiophénolate de sodium dans le DMSO qui est le système classique d'amorçage pour ce type de polymérisation. Différents agents de terminaison, comme l'acide chlorhydrique, le bromure d'allyle ou le bromure de propargyle, ont été utilisés pour terminer les réactions et ont conduit à l'obtention de polyméres hétérotéléchéliques. D'autres dérivés de cyclopropanes présentant des substituants variés ont également été examinés. Ces résultats ouvrent de très intéressantes perspectives dans la préparation d'architectures complexes comme des copolyméres à blocs, greffés ou en étoile. Les premières expériences de copolymérisation ont d'ailleurs été couronnées de succès. Afin d'obtenir de nouveaux canaux ioniques artificiels, différents monomères cyclopropane-1,1- dicarboxylates porteurs d'éthers-couronne ont été synthétisés. La polymérisation anionique par ouverture de cycle de ceux-ci a été étudiée en utilisant soit le thiophénolate de sodium soit le système thiophénol / ButP4 comme amorceur. Ces travaux ont également permis l'obtention d'un nouveau type de poly(éther-ester) qui s'est révélé intéressant comme perméabilisant membranaire. Les interactions des oligo(éther-ester)s avec des membranes modèles planes, des vésicules unilamellaires et des cellules ont été étudiées en collaboration avec des physiciens et des biologistes. Des résultats prometteurs en termes de transport d'ions ont été obtenus et sont présentés dans ce mémoire / The tetrameric phosphazene base ButP4 in association with thiophenol or bis(2-mercaptoethyl) ether has been successfully used in order to initiate the anionic ring-opening polymerization of di-n-alkyl cyclopropane-1,1-dicarboxylates. Well-defined monofunctional or difunctional polymers with a very narrow molecular weight distribution were obtained through a living process at temperatures between 30 and 60°C in THF or between 30 and 100°C in toluene. An excellent agreement is observed between theoretical and experimental Mn values (measured by SEC and by NMR). Other initiating systems such as carbazole or compounds with an acidic proton in association with ButP4 lead also to welldefined polymers. A kinetic study shows a first order with respect to the monomer concentration over the entire conversion range. The initiating system thiophenol / ButP4 in THF shows a much higher reactivity compared to the alkali metal thiophenolate which is the classical one. The living ends were reacted with different terminating agents such as hydrochloric acid, allyl and propargyl bromide thus leading to telechelic polymers. Other cyclopropane derivatives with various substituents have been also examined. These results open very exciting perspectives for the preparation of new architectures such as block and graft copolymers, star polymers. The first copolymer attempts were very successful. With the aim of designing new ion channel biomimics, cyclopropane-1,1-dicarboxylate monomers with crown-ethers substituents were synthesized. The anionic ring-opening polymerization of these monomers has been investigated using either sodium thiophenolate or thiophenol activated by ButP4. Moreover a new alternating poly(ether-ester) was obtained which is an interesting membrane permeabilizer. Its interaction with unilamellar vesicles, planar phospholipidic membranes and cells was studied in collaboration with biophysicists and biologists. Very promising results have been obtained
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Développement de tensioactifs à base d’acides biliaires pegylés pour des applications pharmaceutiquesLe Dévédec, Frantz 03 1900 (has links)
Les acides biliaires sont reconnus comme des tensioactifs d’origine biologique
potentiellement applicables dans le domaine pharmaceutique. Leurs structures en font
une plateforme idéale pour l’obtention de nouvelles architectures polymères. Des
composés synthétisés par polymérisation anionique de dérivés d’oxirane comme
l’oxyde d’éthylène, offre des dérivés amphiphiles pegylés démontrant des propriétés
d’agrégation intéressantes en vue d’une amélioration de la biocompatibilité et de la
capacité d’encapsulation médicamenteuse. Une large gamme d’acides biliaires
pegylés (BA(EGn)x) a été préparée avec comme objectif premier leurs applications
dans la formulation de principes actifs problématiques. Pour cela, une caractérisation
rigoureuse du comportement de ces dérivés (modulation de la longueur (2 < n < 19)
et du nombre de bras (2 < x < 4) de PEG) en solution a été réalisée. Dans le but
d’améliorer la biodisponibilité de principes actifs lipophiles (cas de l’itraconazole),
des nanoémulsions spontanées, composées de BA(EGn)x et d’acide oléique, ont été
développées. L’évaluation in vitro, de la toxicité (cellulaire), et de la capacité de
solubilisation des systèmes BA(EGn)x, ainsi que les paramètres pharmacocinétiques in
vivo (chez le rat), suggèrent une livraison contrôlée par nos systèmes auto-assemblés
lors de l’administration orale et intraveineuse.
Aussi, la synthèse de copolymères en blocs en étoile à base d’acide cholique
pegylés a été effectuée par polymérisation anionique par addition d’un second bloc au
caractère hydrophobe de poly(éther d’allyle et de glycidyle) (CA(EGn-b-AGEm)4).
Selon le ratio de blocs hydrophiles-hydrophobes CA(EGn-b-AGEm)4, des réponses
thermiques en solution (LCST) ont été observées par un point de trouble (Cp) entre 8
oC et 37 oC. Un mécanisme de formation d’agrégats en plusieurs étapes est suggéré.
La thiolation des allyles des PAGE permet une fonctionnalisation terminale à haute
densité, comparable aux dendrimères. Les caractérisations physico-chimiques des
CA(EGn-b-AGEm-NH2)4 et CA(EGn-b-AGEm-COOH)4 indiquent la formation de
structures auto-assemblées en solution, sensibles à la température ou au pH. Cette
fonctionnalisation élargie le domaine d’application des dérivés d’acides biliaires
pegylés en étoile vers la transfection d’ADN, la livraison de siRNA thérapeutiques ou
encore à une sélectivité de livraison médicamenteux (ex. sensibilité au pH, greffage
ligands). / Bile acids are natural compounds and may have potential for pharmaceutical applications. Their structures provide an interesting platform for polymerization to obtain well-defined architectures. The anionic polymerization of oxirane derivatives, mainly PEG derivatives, endowed new aggregation properties and improvement of biocompatibility of the new amphiphilic polymers based on bile acids.
A library of pegylated bile acids (BA(EGn)x) was prepared for the formulation of lipophilic drugs. The aqueous physicochemical behaviors of these derivatives (modulation of the length (2 < n < 19) and the number (2 < x < 4) of PEG arm) were investigated.
In order to improve the bioavailability of insoluble active compounds (itraconazole, an antifungal drug), a binary system based on the association of BA(EGn)x and oleic acid, formed self-emulsifying drug delivery systems. The in vitro evaluation of cell toxicity and solubilization capacities of the BA(EGn)x systems followed by the in vivo evaluation in rats of the pharmacokinetic parameters demonstrated the advantages of our self-assembled system for controlled drug delivery for both oral and intravenous administration.
Star-shaped block copolymers of pegylated cholic acid (CA(EGn-b-AGEm)4) were prepared by the introduction of a second hydrophobic block of PAGE poly(allyl glycidyl ether). They demonstrated thermosensitivity (8 oC < LCST < 37 oC) in aqueous solution, suggesting a mechanism based on the formation of aggregates in two steps. The PAGE block with pendant groups may facilitate futher functionalization. The thiolation of allyl yields a new class of charged PEGylated star polymers (with multiple amines or carboxylic groups). CA(EGn-b-AGEm-NH2)4 and CA(EGn-b-AGEm-COOH)4 derivatives showed self-assembled structures in solution with temperature and pH responsiveness, respectively. This functionalization may lead to broader application of pegylated star derivatives in DNA transfection systems, siRNA delivery systems or as selective delivery system (pH-dependent).
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Pyridine and amine functionalized polymers by anionic and controlled free radical polymerization methodsNdawuni, Mzikayise Patrick 07 1900 (has links)
The synthesis of dipyridyl functionalized polysulfones with improved hydrophilicity, enhanced membrane morphology and excellent ATRP polymeric ligand properties was conducted by the following method:
(a) the formation of lithiated polysulfone from unmodified polysulfone and the subsequent reaction with 2,2'-vinylidenedipyridine in tetrahydrofuran at -78 oC under argon atmosphere to afford the corresponding dipyridyl functionalized polysulfone. The stoichiometry of the reaction affects the degree of functionalization of the product. When equimolar amounts of 2,2'-vinylidenedipyridine are added to the lithiated polysulfone, the degree of functionalization obtained was 45%. However, the addition of 10% and 20% molar excess of 2,2'-vinylidenedipyridine to the corresponding lithiated polysulfone produced dipyridyl functionalized polysulfones with degrees of functionalization of 80% and 95%, respectively; and
(b) the membranes obtained from unmodified polysulfone as well as dipyridyl functionalized polysulfones were characterized by atomic force microscopy, scanning electron microscopy, pure water permeation measurements and contact angle measurements.
Amine chain end functionalized polystyrene and poly(methyl methacrylate) were prepared by Atom Transfer Radical Polymerization (ATRP) methods as follows:
(a) •-Aminophenyl functionalized polystyrene was prepared in quantitative yields by ATRP methods using a new primary amine functionalized initiator adduct, formed in situ by the reaction of 1-(4-aminophenyl)-1-phenylethylene and (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst in diethyl ether at 110 oC, for the polymerization of styrene.(b) New •-bis(aminophenyl) and •,ω-tetrakis(aminophenyl) functionalized polymers were prepared in quantitative yields by the ATRP method using the following synthetic strategy:
(i) the initiation of styrene polymerization with a new primary diamine functionalized initiator adduct, generated in situ by the reaction of stoichiometric amounts of 1,1-bis(4-aminophenyl)ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as catalyst, afforded •-bis(aminophenyl) functionalized polystyrene; and
(ii) •-bis(aminophenyl) functionalized poly(methyl methacrylate) was prepared by the ATRP method using the primary diamine functionalized initiator adduct as initiator for methyl methacrylate polymerization; and
(iii) well defined •,ω-tetrakis(aminophenyl) functionalized polystyrene was prepared by the post ATRP chain end modification reaction of •-bis(aminophenyl) functionalized polystyrene with 1,1-bis(4-aminophenyl)-ethylene at the completion of the polymerization reaction.
(c) Similarly, •-bis(4-dimethylaminophenyl) functionalized polystyrene was prepared by using a new tertiary diamine functionalized initiator adduct, formed in situ by treatment of equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]-ethylene with (1-bromoethyl)benzene in the presence of copper (I) bromide/2,2'-bipyridyl as the catalyst in diphenyl ether at 110 oC for the initiation of styrene polymerization by the ATRP method. Furthermore, the ATRP of methyl methacrylate, initiated by the new tertiary diamine functionalized initiator adduct, produced •-bis(4-dimethylaminophenyl) functionalized poly(methyl methacrylate). In addition, •,ω-tetrakis(4-dimethylaminophenyl) functionalized polystyrene was synthesized via a post ATRP chain end modification reaction of •-bis(4-dimethylaminophenyl) functionalized polystyrene with equimolar amounts of 1,1-bis[(4-dimethylamino)phenyl]ethylene at the completion of the polymerization process.
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Quantitative yields of the different amine functionalized polymers with predictable number average molecular weights (Mn = 1.3 x 103 – 16.4 x103 g/mol), narrow molecular weight distributions (Mw/Mn = 1.03 – 1.29) and controlled chain end functionality were obtained.
Polymerization kinetics data was employed to determine the controlled/living character of each ATRP reaction leading to the formation of the different amine chain end functionalized polymers. The polymerization processes were monitored by gas chromatographic analyses. Polymerization kinetics measurements for all reactions show that the polymerizations follow first order rate kinetics with respect to monomer consumption. The number average molecular weight of the amine functionalized polymers increases linearly with percentage monomer conversion and polymers with narrow molecular weight distribution were obtained.
The ATRP of styrene, catalyzed by a novel dipyridyl functionalized polysulfone/CuBr supported catalyst system, afforded well defined polystyrene with predictable number average molecular weight and narrow molecular weight distribution in a controlled/living free radical polymerization process.
The substituted 1,1-diphenylethylene initiator precursor derivatives and the functionalized polymers were characterized by nuclear magnetic resonance spectrometry, fourier transform infrared spectroscopy, thin layer chromatography, column chromatography, size exclusion chromatography, non-aqueous titrations, differential scanning calorimetry and thermogravimetrical analysis. / Chemistry / M. Sc. (Chemistry)
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Polymérisation anionique des époxydes par activation du monomère : monomères renouvelables et polymères fonctionnalisésBrocas, Anne-Laure 04 December 2011 (has links)
La polymérisation anionique par activation du monomère permet d’accéder à une large gamme de polyéthers en utilisant un système amorçant à base d’un nucléophile associé au triisobutylaluminium. Cette voie a permis d’accéder à des chaînes polyéthers fonctionnalisées par des groupements hydroxyle à chaque extrémité. La (co)polymérisation de l’éther allylglycidique avec d’autres éthers cycliques a été réalisée puis les (co)polymères correspondants ont été post-fonctionnalisés pour introduire en particulier des fonctions cyclo-carbonate destinées à réagir avec des amines pour générer des fonctions hydroxyuréthane et ainsi préparer des matériaux type polyuréthane par une chimie sans isocyanate. Enfin des dérivés du pin, de la famille des acides résiniques, ont été modifiés chimiquement pour élaborer des matériaux de type résine époxyde et polyuréthane sans isocyanate. La polymérisation anionique par activation du monomère a également pu être réalisée sur un monomère époxydé issu de cette ressource. / Monomer-activated anionic polymerization allows the obtention of versatile polyethers using nucleophilic species in the presence of a Lewis acid, i.e. triisobutylaluminium. This method enables the synthesis of α-,ω-plurihydroxytelechelic polyethers. The (co)polymerization of allyl glycidyl ether with various epoxides allowed the preparation of copolyethers with reactive side groups. A cyclo-carbonate functionalization was carried out in order to introduce hydroxyurethane functions by reaction with amines. This reaction allows the preparation of isocyanate-free polyurethane. Finally, resinic acids were modified chemically to prepare epoxy resins and isocyanate-free polyurethanes. A polyether based on epoxidized resinic derivatives was also synthesized by ring-opening anionic polymerization and monomer activation.
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