Multifunctional monomers on the basis of acryl- and methacryl derivatives were synthesized and different protective groups were used. After polymerization the protective groups were removed by different methods. Various initiators for the NMP of the monomers were synthesized and the reaction conditions were optimized. The results showed that NMP was not a suitable method for multifunctional acryl- and methacryl derivatives to achieve well-defined homopolymers, although it was successful for control of polymerization of styrene and block copolymerization of multifunctional acryl- and methacryl derivatives with alkoxyamine terminated polystyrene. The ATRP of multifunctional acrylates and methacrylates has been successfully performed, as well as the block copolymerization of multifunctional acrylates and methacrylates. Relatively low polydispersities of the corresponding polymers (PD=1.18-1.36) and reasonably high rates of polymerization could be achieved when Me6TREN and PMDETA were used as ligands. However, the ATRP of multifunctional acrylamides and methacrylamides failed. The RAFT-polymerization of styrene, acrylamide and acrylate using BDTB as a CTA and AIBN as an initiator afforded polymers with narrow molecular weight distribution (PD=1.13-1.26). A kinetic investigation and the further synthesis of block copolymers using dithioester-terminated homopolymers as macroCTAs showed that the RAFT polymerization of acrylamide M9b proceeded in a living manner. However, BDTB does not control the reaction of methacrylic monomers, such as methacrylates and methacrylamides. The bulk phase behavior of the block copolymers were examined by means of DSC and the surface behaviors of block copolymers as thin layers were examined with AFM. Two-phase transitions in the block copolymers were observed clearly by DSC, indicative of the appearance of phase separations, which were seen in an AFM image. In conclusion, multifunctional acryl- and methacryl derivatives failed to achieve well-defined homopolymers by NMP. However, this method was successful for block copolymerization of multifunctional acryl- and methacryl derivatives with alkoxyamine terminated polystyrene. Multifunctional acrylates and methacrylates were successfully homopolymerized and block copolymerized by ATRP. Multifunctional acrylates and acrylamides were suitable for homopolymerization and block copolymerization by the RAFT process. Thus far, it is difficult to homopolymerize multifunctional methacrylamides in controlled way.

Diese Arbeit beschäftigt sich mit der Synthese neuer photoreaktiver Polymere, die bei Bestrahlung mit Licht (Hg-Dampflampe, fs-gepulster Ti:Sa-Laser) definierte Reaktionen durchlaufen. Mittels kontrolliert-radikalischer Polymerisation und anschließender polymeranaloger Reaktion wurden verschiedene Azobenzen-Derivate, Arylazosulfonat-Derivate und photolabil geschützte Aminogruppen (Nitroveratryloxycarbonyl, Nvoc) in Methacrylat-Polymere eingeführt. Diese Strukturen wurden ausführlich hinsichtlich ihrer Struktur und vor allem ihrer photochemischen Eigenschaften (Extinktionskoeffizienten, Zerfallskinetik) untersucht. Dünne Schichten (d<30nm) der so hergestellten Materialien wurden bei der Entwicklung einer neuen photolithographischen Methode, der plasmonischen Nanolithographie, eingesetzt.

Bioinspirierte Polymere, die die Multidomänenstruktur des Muskelproteins Titin imitieren, wurden auf Grundlage von zuvor synthetisierten, zyklischen Präpolymeren, die Wasserstoffbrückenbindungen-tragende Monomere enthalten, hergestellt und hinsichtlich ihrer mechanischen Eigenschaften untersucht.  Zunächst wurde die Ringexpansionspolymerisation (REP) zur Erzeugung zyklischer Makromoleküle, die auf einer von Nishikubo et al. entwickelten, lebenden Gruppentransferpolymerisation von Thiiranmonomeren mit Acylgruppen-tragenden Initiatoren basiert, eingehend untersucht. Im Speziellen wurde ein System, bestehend aus dem zyklischen Initiator 2,4-Thiazolidindion (TZD) und Derivaten desselben, dem Katalysator Tetrabutylammoniumchlorid, verschiedenartig substituierten Thiiranmonomeren 2-(Phenoxymethyl)thiiran (PMT), 2-Methylthiiran (MT), 2-(tert-Butoxymethyl)thiiran (TBMT), 2-((o-Methylphenoxy)methyl)thiiran (MPMT) und dem Lösungsmittel N-Methylpyrrolidin-2-on verwendet. Bei der Insertion der Monomere MT, TBMT und MPMT in TZD, die unter guter Kontrolle des Polymerisationsgrads und der Dispersität stattfand, wurde eine Verschmelzung der Ringe zu größeren Ringstrukturen mit einem Verschmelzungsgrad von bis zu zwei, bei Verwendung von PMT sogar von bis zu vier beobachtet. Der Grad dieser Verschmelzung nahm im Fall von PMT mit zunehmender Monomerkonzentration, zunehmendem molaren Monomer-zu-Initiator-Verhältnis und zunehmender Reaktionstemperatur ab, während er bei den anderen Monomeren keine Konzentrations- und Temperaturabhängigkeit zeigte. Durch Anpassung der Molmassenverteilungen mittels einer Summe von Gauß-Funktionen im Fall der PMT-Polymere konnte die zeitliche Änderung der molaren Anteile der verschiedenen Ringspezies verfolgt werden. So wurden für Polymerkonzentrationen von 14 bis 52 Gew-% Geschwindigkeitskoeffizienten der Verschmelzung, die sich über Größenordnungen von 10^(−2) bis 10^(−6) L/mol/s erstrecken, ermittelt. Bei Verwendung von in 3-Position substituierten TZD-Derivaten wurde eine Zunahme der Anzahl verschmolzener Makrozyklen von bis zu sieben festgestellt. Die Bildung zyklischer Strukturen wurde mittels Massenspektrometrie und rasterkraftmikroskopischer (AFM) Aufnahmen gezeigt.  Neben den Homopolymerisationen wurden zyklische (AB)n-Multiblockcopolymere aus MT und PMT mit bis zu acht aus der Ringverschmelzung resultierenden Blöcken synthetisiert. Sie zeigten im Zugversuch, aufgrund der verschiedenen Topologien, im Vergleich zu linearen Diblockcopolymeren ähnlicher Zusammensetzung, deutliche Unterschiede in der maximalen Zugdehnung und der Zähigkeit.  Weiterhin wurden die eingangs erwähnten bioinspirierten Polymere durch Kombination von zyklischen und linearen Segmenten hergestellt und auf ihre mechanischen Eigenschaften untersucht. Dazu wurden zyklische (ABC)n-Multiblockcopolymere, die zusätzlich einen kurzen Block des Monomers Ethyl-2-(4-(thiiran-2-ylmethoxy)benzamido)acetat (ETBAA) enthielten, der zur Ausbildung selbstkomplementärer Wasserstoffbrückenbindungen in der Lage ist, synthetisiert. Diese Präpolymere wurden mittels 1,3-dipolarer Cycloaddition in einer Polyadditionsreaktion mit einem niedermolekularen, bifunktionellen Verknüpfungsagens oder mit monofunktionellem Poly-n-butylacrylat (PBA) bzw. Polymethylacrylat (PMA), welche mittels RAFT-Polymerisation hergestellt wurden, verknüpft. So konnte im ersten Fall eine Poly-Ringpolymer-Topologie mit bis zu 19 nachgewiesenen Wiederholeinheiten und im zweiten Fall ein Polymer mit Kette–Ring–Kette-Topologie erhalten werden.  Untersuchungen der Proben im Zugversuch zeigten beim Kette–Ring–Kette-Polymer bis auf eine höhere Elastizität keine verbesserten Materialeigenschaften im Vergleich zum linearen PMA-Präpolymer. Die Poly-Ringpolymere hingegen zeigten im Gegensatz zu den Ringpolymeren ein einzigartiges Spannungs-Dehnungsverhalten, bessere Elastizitätseigenschaften und eine Erhöhung der anwendbaren Spannung bei gleicher Dehnung. Dies wurde durch den Einfluss inter- und intramolekular ausgebildeter physikalischer Bindungen durch die enthaltenen selbstkomplementären Wasserstoffbrückenbindungsmotive hervorgerufen. Eines der untersuchten Poly-Ringpolymere zeigte aufgrund der Ausbildung eines reversiblen physikalischen Netzwerkes sogar ein Formgedächtnis und die Fähigkeit zu einer partiellen Selbstheilung.

Les structures sialylées sont présentes à la surface des cellules sous forme de glycoconjugués,couplés à des protéines ou des lipides. Ces structures jouent un rôle important dans divers processusbiologiques que ce soit à travers l’interaction avec des lectines, ou de par leurs propriétés physicochimiques.Ces structures sont également impliquées dans diverses pathologies et on constatenotamment une forte augmentation du taux d’acides sialiques chez les individus atteints de cancer,due à une surexpession de structures naturelles mais aussi à l’apparition de nouveaux motifs,naturellement absent chez l’individu sain. L’ensemble de ces structures sialylées présente un intérêtsoit par leur rôle biologique soit à cause de leur expression spécifique dans les cancers. Leurobtention est très difficile par voie chimique et la synthèse enzymatique in vitro est efficace mais trèscoûteuse en nucléotide-sucre et ne sont pas adaptées à une production à l'échelle préparative.Dans un premier temps, ces travaux de thèse s’intéressent à la synthèse bactérienne par ingénieriemétabolique d'acides polysialiques fonctionalisés. Ces polysaccharides présentent divers intérêts.Tout d’abord il est possible de les coupler à des protéines actives pour en augmenter le temps dedemi-vie in vivo. Mais ces polysaccharides peuvent également être utilisés dans le cadre de thérapievaccinale, soit contre des bactéries pathogènes de types Neisseria meningitidis qui le présententcomme polysaccharide capsulaire, soit contre les cellules cancéreuses surexprimant cette structure.Ensuite nous avons cherché à obtenir des oligosaccharides spécifiques des cancers, les motifssialylTn, et siallTF, toujours par ingénierie métabolique d’E. coli. Le sialylTn a été couplé à uneplateforme peptidique immunogène afin de construire un candidat vaccin qui a été testé in vitro et invivo sur la souris. / Sialylation is an important feature of glycolipids and glycoproteins of animal cell surfaces. Sialylatedmotifs are involved in many biological processes through lectin interactions or because of theirphysico-chemical properties. There is a great variety of sialylated structural motifs, and in manycases, there is a structure-relationship between the sialylated profile of and some pathologicprocesses. In cancer, there is an increase of sialylation including the apparition of newly andspecifically related sialylated structures belonging to the so-called tumor-associated carbohydrateantigens (TACA). Those structures present a particular interest, but their chemical or chemoenzymaticsynthesis is costly and quite unappropriated for preparative scale.This work addresses to the bacterial synthesis of sialylated motifs through the metabolic engineeringof Escherichia coli. The first part of the thesis deals with the biosynthesis of polysialylatedconjugatable motifs. Those motifs present various biological properties, such as an increase of thelife-time of therapeutic proteins; they also belong to the TACA family since over-expressed incancers. In addition, some of them are bacterial-specific motifs such as in pathogenic Neisseriameningitidis. Altogether, polysialylated conjugates can be useful for the synthesis of therapeuticdrugs and vaccines. The second part of the thesis describes a new way of producing sialylated Tn andTF carbohydrate antigens by metabolic engineering. The sialylTN motif was coupled to a peptidic andimmunogenic scaffold being a potential vaccine candidate, and its ability of raising specific antibodieswas assayed in mouse.

Les polymères fonctionnalisés par des groupements phosphonates ont un fort potentiel applicatif comme superplastifiants dans les pâtes de ciment. Des copolymères à blocs fonctionnels ont été synthétisés par polymérisation RAFT/MADIX afin d'accéder à des polymères de masse molaire, d'architecture et de composition contrôlées. Le monomère principalement utilisé a été l'acide vinylphosphonique (VPA). L'amélioration de la cinétique ainsi que la conversion finale lors de la polymérisation du VPA a été un des principaux objectifs de la thèse, en vue de synthétiser des copolymères diblocs PEG-PVPA. Ensuite des copolymères à blocs ont été synthétisés à l'aide d'un disulfure de xanthate. Ce nouveau procédé a permis d'obtenir des structures de copolymères à blocs plus complexes à bas de MPEGMA et de VPA, dont la synthèse à partir d'un agent de contrôle RAFT conventionnel aurait été relativement ardue. Des essais ont été menés sur des pâtes cimentaires afin d'évaluer les propriétés des différents copolymères. Les effets de l'adsorption des copolymères à blocs sur la mise en œuvre du béton ont été évalués et comparés à des superplastifiants phosphonatés commerciaux. / Phosphonic acid-functionalized polymers show great promise as superplasticizers in cement mixtures. Functional block copolymers were synthesized by RAFT/MADIX polymerization to obtain polymers of controlled molecular weight, architecture and composition. The principal monomer used was vinylphosphonic acid (VPA). The enhancement of the kinetics of VPA polymerization and the final yield was one of the aims of the thesis. Block copolymers were then synthesized using xanthate disulfide as a chain transfer agent. This new process enabled us to obtain complex structures that would be difficult to synthesize using a more conventional RAFT process. The effects of block copolymer adsorption on cement workability were assayed with reference to a commercially available phosphonated superplasticizer.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present work describes a methodology of controlled synthesis of block copolymers by one-pot reactions involving simultaneous RAFT and ROP processes mediated by a bifunctional compound which acts as a chain transfer agent (CTA) for the RAFT process and co-initiator of the ROP process. Reactions involving the RAFT of Styrene (St) and the ROP of ε-Caprolactone (ε-CL) were performed to obtain PS-b-PCL diblock copolymers. The catalysts Sn(Oct)2 and diphenyl phosphate (DPP) were evaluated in the ROP process. Diphenyl phosphate is the most appropriate for this kind of reaction, since Sn(Oct)2 proved to be avid when interacted with CTA, interfering antagonistically in the radical equilibrium of the RAFT process. The reactions were always controlled when DPP was used as a ROP catalyst, wherein copolymers with narrow molar mass distribution were obtained in the end. This methodology was employed in the synthesis of other linear and graft amphiphilic block copolymers, proving to be an excellent alternative for this purpose. Thermoresponsive copolymers based on Poly(oligo(ethylene glycol)methyl ether methacrylate) (POEGMA) and pH responsive based on Poly(acrylic acid) (PAA) were obtained. The physicochemical properties of the copolymers were investigated in solid state as well as in solution, and the results are in total agreement with values reported in the literature. / Este trabalho descreve uma metodologia de síntese controlada de copolímeros em bloco por reações one-pot envolvendo processos RAFT e ROP simultâneos, mediados por um composto bifuncional que atua como agente de transferência de cadeia (CTA) para o processo RAFT e co-iniciador do processo ROP. Reações envolvendo a RAFT do estireno (St) e a ROP da ε-Caprolactona (ε-CL) foram realizadas para obter copolímeros dibloco PS-b-PCL. Os catalisadores Sn(Oct)2 e difenil fosfato (DPP) foram avaliados, sendo o último o mais apropriado para este tipo de reação, uma vez que Sn(Oct)2 mostrou-se ávido por interações com o CTA, interferindo antagonicamente no equilíbrio de radicais do processo RAFT. As reações mantiveram o caráter controlado quando DPP foi usado como catalisador ROP, sendo que ao final, copolímeros com estreita distribuição de massa molar foram obtidos. Esta metodologia foi empregada na síntese de outros copolímeros em bloco anfifílicos lineares e enxertados, se mostrando uma excelente alternativa para este propósito. Copolímeros termoresponsivos à base de Poli(metacrilato de poli(etilenoglicol)metil éter) (POEGMA) e pH responsivos à base de Poli(ácido acrílico) (PAA) foram obtidos. As propriedades físico-químicas dos copolímeros foram investigadas em estado sólido e em solução, e os resultados estão em plena concordância com valores relatados na literatura.

Das Ziel der Arbeit bestand in der Präparation von multifunktionellen phasenseparierten Blockcopolymerfilmen, die an der Oberfläche über polymeranaloge Reaktionen modifiziert werden können. Dafür wurden zunächst phasenseparierte Blockcopolymere über RAFT-Polymerisation synthetisiert, in die sowohl funktionelle als auch Vernetzergruppen integriert wurden. Als funktionelle Monomere kamen dabei Propargylmethacrylat, Propargyloxystyrol, Vinylbenzylchlorid und Pentafluorostyrol zum Einsatz. Die Vernetzergruppen wurden über die Monomere Vinylpyridin, Glycidylmethacrylat, 4-Benzoyl-3-hydroxyphenylmethacrylat und Dimethylmaleinimidobutylmethacrylat eingebaut. Die erhaltenen Polymere wurden hinsichtlich ihrer Molmasse und ihrer thermischen Eigenschaften mit GPC, NMR, DSC und TGA untersucht. Des Weiteren erfolgten polymeranaloge Reaktionen, wie die kupferkatalysierte Cycloaddition von Aziden an Alkinen, eine cäsiumvermittelte Veresterung der Vinylbenzylchloridgruppe mit Liponsäure als auch eine Substitution am Pentafluorostyrol mit Thiolen, an den synthetisierten Blockcopolymeren. Dünne Filme dieser Blockcopolymere wurden mit Rasterkraftmikroskopie untersucht und dabei teilweise Phasenseparation erhalten. Die Filme wurden darauf chemisch, thermisch als auch photochemisch vernetzt, um die erhaltenen Strukturen zu fixieren. Dabei konnte ein vollständiger Erhalt der Phasenstrukturen nicht erreicht werden. Allerdings zeigten die thermischen als auch photochemischen Vernetzungen die vielversprechendsten Ergebnisse.

Este trabalho de tese tem como objetivo a preparação de látices nanocompósitos à base da argila Laponita RD em emulsão aquosa, via polimerização radicalar controlada por transferência de cadeia via adição-fragmentação reversível (RAFT). A Laponita foi escolhida como carga inorgânica devido principalmente à forma anisotrópica de suas lamelas, o que permite a elaboração de filmes nanoestruturados, mas também por suas propriedades térmicas e mecânicas, por sua alta pureza química e pela distribuição uniforme, em termos de tamanho, de suas partículas. Inicialmente, polímeros hidrofílicos (macroRAFT) à base de poli(etileno glicol) (PEG), de ácido acrílico (AA) ou de metacrilato de N,N-dimetilaminoetila (DMAEMA) que contêm unidades hidrofóbicas de acrilato de nbutila (ABu) (em alguns casos) e um grupo tritiocarbonílico terminal foram sintetizados. Em seguida, a interação entre os macroagentes de controle (macroRAFTs) e a argila foi estudada através de isotermas de adsorção. Atuando como agentes de acoplamento e estabilizantes, esses macroRAFTs foram então utilizados na copolimerização em emulsão do (met)acrilato de metila e do ABu em processo semicontínuo na presença da argila Laponita. Partículas de látex híbrido de diferentes morfologias foram obtidas e os resultados foram correlacionados à natureza e à concentração dos macroRAFTs, ao pH da dispersão macroRAFT/Laponita, à temperatura de transição vítrea do copolímero final (função da composição da mistura de monômeros hidrofóbicos) e às condições de polimerização. As análises de cryo-TEM indicam a formação de lamelas de Laponita decoradas com partículas de polímero (várias partículas de látex localizadas na superfície das lamelas), de partículas do tipo dumbbell, janus, blindadas (partículas de látex decoradas com lamelas de argila em sua superfície) ou ainda de partículas multiencapsuladas (diversas lamelas encapsuladas dentro de uma única partícula de látex). As propriedades mecânicas dos filmes de polímero/Laponita foram estudadas por análise dinâmico-mecânica e correlacionadas à morfologia das partículas e à microestrutura dos filmes. / The aim of this work is to prepare Laponite RD-based nanocomposite latexes by aqueous emulsion polymerization, using the reversible addition-fragmentation chain transfer (RAFT) polymerization. Laponite platelets were selected as the inorganic filler due, especially, to their anisotropic shape, which allows the production of nanostructured films, but also for their thermal and mechanical properties, their high chemical purity and the uniform dispersity of the platelets. Hydrophilic polymers (macroRAFT) composed of poly(ethylene glycol) (PEG), acrylic acid (AA) or N,N-dimethylaminoethyl methacrylate (DMAEMA) and comprising hydrophobic n-butyl acrylate (BA) units (in some cases) and trithiocarbonate terminal group were initially synthesized. Then, the interaction between the macroRAFTs and the clay was studied through the plot of adsorption isotherms. By acting as coupling agents and stabilizers, the macroRAFT agents were used in the emulsion copolymerization of methyl (meth)acrylate and BA by semi-continuous process in the presence of the clay. Hybrid latex particles with different morphologies were obtained and the results were associated to the nature and concentration of the RAFT (co)polymers, to the pH of the macroRAFT/Laponite dispersion, the glass transition temperature of the final copolymer (function of the composition of the hydrophobic monomers mixture) and to the polymerization conditions. The cryo-TEM images indicate the formation of polymerdecorated Laponite platelets (several latex particles located at the surface of the platelets), dumbbell-like, janus, Laponite-decorated (armored) latex particles, and multiple encapsulated particles (several platelets inside each latex particle). The mechanical properties of polymer/Laponite films were studied by dynamic mechanical analysis and correlated with the particles morphology and the films microstructure.

Nos últimos anos, a incorporação de partículas inorgânicas em uma matriz polimérica com a finalidade de se obter sistemas híbridos orgânico/inorgânico utilizando diferentes técnicas de polimerização tem recebido grande atenção. Neste sentido, preservar e controlar as propriedades físico-químicas das partículas inorgânicas torna-se essencial para manter a integridade destas em nanoescala, bem como para obtenção de dispersões uniformes, magnificando os efeitos de reforço e demais ganhos de propriedades desejadas para a matriz polimérica. Quando se utiliza partículas inorgânicas anisotrópicas tais como a montmorilonita, silicato lamelar mais utilizado para obtenção de nanocompósitos do tipo polímero/silicato lamelar, este controle apresenta-se como um problema particularmente desafiador. Nesse contexto, a polimerização radicalar controlada (PRC) vem se destacando como uma importante via para atingir os objetivos mencionados acima, encontrando-se na literatura diversas estratégias de síntese em meio a solventes orgânicos na qual a efetiva nanoencapsulação de partículas inorgânicas dá-se por meio do crescimento de cadeias poliméricas na superfície destas estruturas inorgânicas. Entretanto, poucos trabalhos são encontrados envolvendo rota de obtenção semelhante em meio aquoso, tais como suspensão, emulsão e miniemulsão, processos estes que possuem grande interesse industrial, ambiental e viabilidade real de ampliação de escala quanto à produção.Desta forma, o objetivo deste projeto de pesquisa concentra-se na síntese e na caracterização de nanocompósitos do tipo polímero/silicato lamelar via polimerização radicalar controlada em emulsão. As polimerizações radicalares controladas de estireno em emulsão, via mecanismo de transferência reversível de cadeia por adição-fragmentação (RAFT), foram conduzidas na presença de argila montmorilonita (MMT) e mediadas por dois macroagentes de transferência de cadeia com grupo funcional tri-tioéster, sendo o primeiro constituído de cadeia polimérica não iônica de monoetil éter de poli(etilenoglicol) (MPEG-CPP) e outro derivado do MPEG-CPP contendo adicionalmente um bloco ionizável de poli(ácido metacrílico) incorporado à cadeia polimérica (MPEG-b-PMAA-CPP). Foram avaliados inicialmente os parâmetros de adsorção dos macroagentes MPEG-CPP e MPEG-b-PMAA-CPP na superfície da MMT bem como a influência das variáveis do processo de polimerização na adsorção dos macroagentes na MMT e na estabilidade coloidal dos complexos macroagente RAFT / MMT formados. Posteriormente foram avaliados os efeitos do pH, das concentrações dos macroagente RAFT e de MMT, bem como do tipo de iniciador na cinética de polimerização em emulsão \"ab-initio\" de estireno, conduzidas na ausência de surfatantes. As técnicas utilizadas nos estudos de adsorção e para a caracterização das argilas, dos látices híbridos e dos materiais nanocompósitos incluem: espectroscopia de UV-vis, espalhamento dinâmico de luz (DLS), espalhamento eletroforético de luz (ELS), cromatografia de permeação em gel (GPC), análise termogravimétrica (TGA), calorimetria diferencial de varredura (DSC) e microscopia eletrônica de transmissão (TEM). / In recent years, the incorporation of inorganic particles in a polymer matrix in order to obtain hybrid organic/inorganic systems using different polymerization techniques have received great attention. In this sense, preserve and manage the physical and chemical properties of inorganic particles is essential to maintain its integrity at the nanoscale, as well as to obtain uniform dispersions of them, magnifying the effects of reinforcement and other desired properties into the polymer matrix. When using anisotropic inorganic nanoobjects such as montmorillonite, the most used layered silicate to obtain polymer / layered silicate nanocomposites, this control is presented as a particularly challenging problem. In this context, the controlled radical polymerization (CRP) has been highlighted as an important way to achieve the goals mentioned above, several strategies of organic solvent-borne synthesis can be found in literature in which the effective nanoencapsulation of inorganic particles is given by through the growth of polymer chains on the surface of these inorganic structures. However, few works are found involving obtaining similar route in water-borne, such as suspension, emulsion, miniemulsion, these procedures have great interest in industrial, environmental and actual feasibility of expanding scale in manufacture. Thus, the objective of this research project focuses on the synthesis and characterization of nanocomposite-type polymer / layered silicate via controlled radical polymerization in emulsion media. The controlled radical polymerizations in emulsion, via transfer mechanism for the reversible addition-fragmentation chain (RAFT) have been conducted in the presence of montmorillonite clay (MMT) and mediated by two macroRAFT agents with functional tri-thioesters groups, being the first one constituted by a nonionic poly(ethylene glycol) methyl ether polymeric chain (MPEG-CPP) and the second on being MPEG-CPP derived but containing additionally an ionizable block of poly(methacrylic acid) inserted to its polymeric chain. The parameters of adsorption of MPEG-CPP and MPEG-b-PMAA-CPP agent on the surface of MMT as well as the influence of the polymerization process variables on the adsorption of PEO-RAFT in MMT and colloidal stability of the complex formed macroRAFT agents / MMT were firstly evaluated. Subsequently, the influence of pH, macroRAFT agents and MMT concentrations as well as the type of initiator on the kinetics of RAFT emulsion polymerization were equally evaluated. The techniques used the for adsorption studies and characterization of clays, latexes of hybrid materials and nanocomposites include: UV-vis spectroscopy, dynamic light scattering (DLS), electrophoretic light scattering (ELS), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), dynamic scanning calorimetry (DSC) and transmission electron microscopy (TEM).

No description available.