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L'objet de cette étude est la gravure par plasma de matériaux hybrides SiOC(H) qui sont de nouveaux composés émergents. Leurs propriétés ajustables entre composés organiques et inorganiques leurs donnent de grandes potentialités. Ce travail est dédié à deux applications particulières en microélectronique.<br />Dans un premier temps, notre étude s'est portée sur leurs applications en lithographie optique dans le cadre d'un projet européen (157 CRISPIES n° 2000 30-143) où sont développés de nouveaux polymères contenant un nanocomposé, la molécule POSS (Si8O12) (Polyhedral oligomeric silsesquioxane). Ces polymères pourraient être utilisés dans un procédé de lithographie bicouche car ils sont faiblement absorbants pour les futurs rayonnements, UV à 157 nm, ou X à 13,5 nm. L'analyse de leur surface avant gravure a été particulièrement poussée grâce à une utilisation avancée des mesures XPS. Ce travail a mis en évidence la ségrégation en surface de la molécule POSS. Afin de caractériser la phase de développement plasma du procédé bicouche, ces matériaux ont été gravés en plasma d'oxygène. Des analyses XPS et ellipsométriques montrent le rôle joué par la couche d'oxyde qui se forme à la surface de ces matériaux. Une corrélation est faite entre l'épaisseur de l'oxyde mesurée par XPS et la consommation totale du polymère mesurée par ellipsométrie. L'ensemble de ces résultats nous a amené à développer un modèle cinétique permettant de comprendre les mécanismes de gravure de ces nouveaux composés en plasmas oxydants.<br />Dans un deuxième temps, nous avons étudié l'utilisation de SiOC(H) comme isolant d'interconnexion. En effet, ces matériaux présentent une permittivité électrique plus faible que celle de l'oxyde de silicium classiquement utilisé en microélectronique, on les appelle low-k. Ils permettent d'améliorer les vitesses de transmission des informations au sein des puces. Les plasmas fluorocarbonés (C2F6) avec différents additifs (O2, Ar, H2) ont été utilisés à la fois pour obtenir une vitesse de gravure élevée mais aussi une sélectivité importante avec la couche d'arrêt SiC(H). L'addition d'hydrogène permet d'augmenter la sélectivité tout en conservant une vitesse de gravure élevée. Les caractérisations de surface par XPS quasi in situ montrent tout d'abord que la composition du matériau est modifiée sur quelques nanomètres, avec une diminution de la quantité de carbone. Ensuite, pour les plasmas de C2F6/H2 et C2F6/Ar, une couche fluorocarbonée se superpose à cette couche modifiée et son épaisseur est corrélée aux vitesses de gravure. Des mesures du flux ionique et de la quantité de fluor atomique permettent de mieux appréhender les mécanismes de gravure qui régissent ces matériaux.

<p>Degradation of the mRNA 3'-end located poly(A) tail is an important step for mRNA decay in mammalian cells. Thus, to understand mRNA decay in detail, it is important to identify the catalytic activities involved in degrading poly(A). We identified and purified a 54-kDa polypeptide responsible for poly(A)-specific 3' exonuclease activity in calf thymus extracts. The 54-kDa polypeptide is a proteolytic fragment of the poly(A)-specific ribonuclease (PARN) 74-kDa polypeptide. PARN is a divalent metal ion dependent, poly(A)-specific, oligomeric, processive and cap interacting 3' exonuclease. An active deadenylation complex, consisting of the poly(A)-tailed RNA substrate and PARN, has been identified. The interaction with the 5'-end cap structure stimulates PARN activity and also amplifies the processivity of the deadenylation reaction. Furthermore, the cap binding site and the active site of PARN are separate from each other. To characterise the active site of PARN, we per-formed side-directed mutagenesis, Fe²⁺-mediated hydroxyl radical cleavage and metal ion switch experiments. We have demonstrated that the conserved acidic amino acid residues D28, E30, D292 and D382 of human PARN are essential for PARN activity and that these amino acid residues are directly involved in the co-ordination of at least two metal ions in the active site of PARN. Phosphorothioate modification on RNA substrates revealed that the pro-R oxygen atom of the scissile phosphate group interacts directly with the metal ion(s). Based on our studies, we propose a model for the action of PARN. Similarly to what has been observed for ribozymes, aminoglycoside antibiotics inhibit PARN activity, most likely by the displacement of catalytically important divalent metal ions. Among the aminoglycoside antibiotics tested, neomycin B is the most potent inhibitor. We speculate that inhibition of enzymes using similar catalytic mechanisms as PARN could be a reason for the toxic side effects caused by aminoglycoside antibiotics in clinical practice. </p>

Degradation of the mRNA 3'-end located poly(A) tail is an important step for mRNA decay in mammalian cells. Thus, to understand mRNA decay in detail, it is important to identify the catalytic activities involved in degrading poly(A). We identified and purified a 54-kDa polypeptide responsible for poly(A)-specific 3' exonuclease activity in calf thymus extracts. The 54-kDa polypeptide is a proteolytic fragment of the poly(A)-specific ribonuclease (PARN) 74-kDa polypeptide. PARN is a divalent metal ion dependent, poly(A)-specific, oligomeric, processive and cap interacting 3' exonuclease. An active deadenylation complex, consisting of the poly(A)-tailed RNA substrate and PARN, has been identified. The interaction with the 5'-end cap structure stimulates PARN activity and also amplifies the processivity of the deadenylation reaction. Furthermore, the cap binding site and the active site of PARN are separate from each other. To characterise the active site of PARN, we per-formed side-directed mutagenesis, Fe2+-mediated hydroxyl radical cleavage and metal ion switch experiments. We have demonstrated that the conserved acidic amino acid residues D28, E30, D292 and D382 of human PARN are essential for PARN activity and that these amino acid residues are directly involved in the co-ordination of at least two metal ions in the active site of PARN. Phosphorothioate modification on RNA substrates revealed that the pro-R oxygen atom of the scissile phosphate group interacts directly with the metal ion(s). Based on our studies, we propose a model for the action of PARN. Similarly to what has been observed for ribozymes, aminoglycoside antibiotics inhibit PARN activity, most likely by the displacement of catalytically important divalent metal ions. Among the aminoglycoside antibiotics tested, neomycin B is the most potent inhibitor. We speculate that inhibition of enzymes using similar catalytic mechanisms as PARN could be a reason for the toxic side effects caused by aminoglycoside antibiotics in clinical practice.

This work is generally aimed to synthesize POSS based BCPs via RAFT polymerization, to study their self-assembly behaviors, to research on the effect of POSS self-assembly structure on the bulk properties and to prepare nanostructured hybrid epoxy via self-assembly of POSS based copolymer. In Chapter1, We studied the RAFT polymerization of POSS macromers and capable to synthesize well defined POSS based BCPs with high POSS fraction and different topology such as AB，BAB and (BA)3. The vertex group and the morphology effect on thermo-mechanical properties of POSS based BCPs as well as the structure-property relationship was investigated. Dispersion RAFT polymerization in apolar solvent was applied and various aggregates with different morphology in Chapter2. Cooling induced reversible micelle formation and transition was found and the pathway selection in vesicle formation was investigated. Nano-construction of O/I hybrid epoxy materials based on POSS based copolymers was investigated in Chapter4. The effect of functional group content on miscibility of POSS based statistic copolymer and epoxy was investigated. A novel method to nanostructure epoxy hybrid involving self-assembly of POSS based BCPs in epoxy was presented. High homogeneity and well size/morphology control of core-corona structure containing rigid POSS core and soluble PMMA corona in networks were obtained.

Le passage sélectif de molécules à travers la membrane interne des mitochondries est essentiel aux processus métaboliques des cellules eucaryotes. Cette communication cellulaire est assurée par des protéines transmembranaires de la famille des transporteurs mitochondriaux (MCF). Le transporteur ADP/ATP (AAC) est le membre le plus connu et le mieux caractérisé de cette famille. Il est responsable de l'import d'ADP dans la matrice mitochondriale et de l'export d'ATP après synthèse vers le cytosol. La structure d'AAC est connue mais plusieurs questions restent ouvertes concernant le mécanisme du transport, la sélectivité et l'état oligomérique, controversé, de la protéine. Pendant plusieurs années des études biochimiques réalisées sur la protéine solubilisée en détergent étaient en faveur d'une organisation dimérique du transporteur, mais la structure d'AAC, monomérique a remis en cause ce dogme. Afin de caractériser l'organisation oligomérique d'AAC in vivo, nous avons combiné plusieurs approches. Nous avons réalisé des expériences de FRET (Fluorescence Resonance Energy Transfer) directement sur des cellules mammifères ou bactériennes (E. coli) surexprimant la protéine AAC fusionnée avec des sondes FRET. En parallèle, nous avons mis au point des tests fonctionnels afin de contrôler l'état des mitochondries et l'activité du transporteur dans ces cellules. Enfin nous avons étudié la stoechiométrie de liaison de l'inhibiteur carboxyatractyloside grâce à des mesures de respiration sur des mitochondries extraites de foie de rat et placées dans différents états métaboliques. L'ensemble des résultats présentés dans ce manuscrit ont permis de montrer que 1) l'unité fonctionnelle d'AAC est monomérique 2) l'organisation structurale d'AAC dans les membranes natives dépend de l'état métabolique des mitochondries et peut être associée à des phénomènes de régulation. / The transport of small molecules through the inner mitochondrial membrane is essential in eukaryotic metabolism and is selectively controlled by a family of integral membrane proteins, the Mitochondrial Carrier Family (MCF). The ADP/ATP carrier (AAC), which is responsible for the import of ADP to the matrix of mitochondria and the export of newly synthesized ATP toward the cytosol, is the best-known and characterized MCF member. Although its structure sheds light on several aspects of the carrier activity, additional investigations are still required to decipher the whole transport mechanism, to understand the specificity and to characterize the controversial oligomeric state of the protein. For many years, based on studies mainly carried on detergent solubilized AAC the general consensus has been in favor of a dimeric organization of the carrier. The AAC three-dimensional structure, monomeric, broke this dogma. In order to get a precise insight into the in vivo oligomeric organization of AAC we combined several approaches. Fluorescence resonance energy transfer (FRET) measurements were performed directly on mammalian and E.coli cells expressing AAC labeled with several types of FRET probes. In parallel, different functional assays were established to control the state of the mitochondria in these cells and the transport activity of these AAC fusions. Lastly, measurements of the respiration rate coupled to the titration of the inhibitory effect of carboxyatractyloside on isolated rat liver mitochondria were used to investigate the organization of AAC in native mitochondria within two regimes of oxidative phosphorylation. Taken together the results described herein revealed that 1) AAC can function mechanistically as a monomer, 2) the organization of AAC in native membranes might be related to the state of the mitochondria and be involved in regulation.

Chapter 1: Amphiphilic self-assembled systems as nanocarriers Nanocarriers are the nanometric size molecular assemblies that are used for the transport of small molecules into their non-solvating environments. These systems find major applications as drug delivery systems (DDS) in pharmacological research. These drug delivery systems improves solubility and stability of the drug molecules through encapsulation and also offer additional advantages like target specificity and stimuli responsive release of the drug molecules. Several types of DDS are reported in the literature, which can be prepared by a variety of processing techniques. Of these, molecular self- Chart 1: Developments in the design of amphiphilic nanocarriers assembly has attained considerable attention due to its greater tunability and control in the preparation of nanocarriers. In this chapter we discussed about the amphiphilic nanocarriers which are prepared through self-assembly of amphiphiles through hydrophobic interactions. Several developments in the area of amphiphilic nanocarriers such as di-block polymeric systems, dendritic systems and core-shell architectures are also mentioned. We also highlighted some recent developments in the design of amphiphilic nanocarriers through supramolecular interactions and advantages of such systems. Chapter 2: Bile acid derived dendrons and their application as nanocarriers Host-guest chemistry is well known for dendritic systems. To understand the influence of steric crowding, dendritic effect and importance of number of hydroxyl groups on the bile acid backbone in the host-guest chemistry of bile acid dendrons, we designed and synthesized a new series of C3 symmetric systems and studied the above-mentioned objectives through extraction of polar dyes into nonpolar media. Dye extraction experiments performed using trimeric molecules suggested that only the cholate derivatives (3 and 4) showed considerable extraction of the polar dyes into chloroform; deoxycholate derivatives did not show any extraction, thus emphasizing the importance of the number of hydroxyl groups for dye extraction in these molecular architectures. The effect of steric crowding at the core of these trimeric molecules was shown by efficient extraction of the dyes with the triethylbenzene core (4) compared to the benzene core (3). Greater influence of the aggregates in the case of triethylbenzene core on the extracted dye was also manifested in the Chart 2: Structures of the designed molecules 1-6 value of the induced circular dichroism signal. Surprisingly, a higher analogue in these molecular architectures showed lesser efficiency in dye extraction (on a per bile acid residue basis) compared to the trimers, suggesting a more compact structure for the higher analogue. This was supported by molecular modeling studies. Generality of these systems as nanocarriers for hydrophilic dyes was investigated by screening several other dyes and polar molecules, which are diverse in their structure and functionalities. All these experiments suggested a dependency of the extraction profile on the size of the dye molecule. This was also examined by dynamic light scattering studies, which showed larger size and wider distribution in the size of the aggregates in the case of larger dyes. We also demonstrated selective extraction of a single dye molecule from a blended food color (apple green) using one of the trimer (4) and demonstrated solvent dependent morphological changes in these compounds using electron microscopy. The self-assembly of these amphilic molecules at the air-water interface was studied through Langmuir monolayer studies. Chart 3: Structure of polar guest molecules (Cresol red (7). Erioglaucine (8), Eriochrome black T (9),) phenyl β-D-glucopyranoside (10) and Eosin B (11) Chapter 3: Design and synthesis of bile acid derived surfactants: Study of their aggregation and potential applications Bile acids are facially amphiphilic systems and their amphiphilicity can be improved by attaching polar groups on the bile acid back bone or by synthesizing oligomeric systems which show better self-assembly compared to their monomeric units. To study and improve the amphiphilicity of bile acids, we designed and synthesized a new tripodal surfactant system, with a phosphine oxide based central core to which the bile acids were attached through the C-3 position using click chemistry. Our molecular design also offers added advantage of studying the influence of the stereochemistry at the C-3 position on the aggregation of these molecular architectures. We synthesized trimeric systems with both cholic and deoxycholic acids attached to the central phosphine oxide core with α and β stereochemistry at the C-3 position. Aggregation of these molecules was studied by surface tension measurements, dye extraction studies and NMR. All these compounds showed aggregation at micromolar concentrations. NMR studies suggested changes in the structure of the aggregates at higher temperature and these changes were studied by DLS, which suggested thermodynamically stable monodispersed aggregates for cholic acid derivatives (13 and 15) at higher temperature. These aggregates are stable even after cooling to room temperature and with time. The aggregates of these derivatives were also characterized by atomic force microscopy. Gelation was observed in the case of α derivatives (12 and 13) in phosphate buffer (0.1 M) at pH 7.5 for both deoxy and cholic derivatives, which emphasized the influence of stereochemistry at C-3 position in these architectures. These gels were characterized by rheology experiments. Finally, the possible utility of these micellar systems as model systems to study photophysical processes was demonstrated through lanthanide sensitization experiments in these micellar solutions. Chart 4: Structure of the designed molecules Chapter 4: Synthesis of oligomeric bile acid-taurine conjugates: Study of their aggregation and efficiency in cholesterol solubilization Bile acids are bio-surfactants that are used for the emulsification of fats, vitamins etc. in our body. Bile salts also solubilize the excess cholesterol in our body through mixed micelle formation in the bile and when the bile gets saturated with cholesterol, it leads to cholesterol gallstone formation, which needs to be treated. Ursodeoxycholic acid (UDCA) is used as drug in some cases for the solubilization of (small) cholesterol gallstones, even though the efficiency to solubilize cholesterol is less for UDCA compared to the other bile acids (UDCA is less toxic than the others). So there is a need to develop new cholesterol solubilizing agents. Since oligomeric systems can aggregate better, we designed and synthesized two tetramer taurine conjugates, which differ in the spacer between the bile acid units. Since these conjugates are not soluble in water, their solubility and aggregation was studied in 10% MeOH/Water using pyrene fluorescence experiments. Aggregation studies suggested better aggregation for these molecules compared to their monomeric analogues. These aggregates were also characterized byDLS and electron microscopy. These systems were subsequently studied as nanocarriers for liphophilic dye molecules into aqueous media. Finally, the influence of oligomeric effect in cholesterol solubilization was investigated by cholesterol solubilization studied using these two tetramer taurine compounds and a control, sodium taurocholate. These studies suggested efficient solubilization of cholesterol by oligomers compared to monomeric analogues.(For structural formula pl see the abstract file)

Orientadores: Paulo Pinto Joazeiro, Luiz Carlos Alves / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T05:21:21Z (GMT). No. of bitstreams: 1 Silva_MonicaMariaMoreira_D.pdf: 3522039 bytes, checksum: c8adbfe076ccc79eaa19efeb2f0d8fe7 (MD5) Previous issue date: 2014 / Resumo: Em camundongos, a sínfise púbica (SP) é metabolicamente ativa durante a prenhez. As adaptações orquestradas por hormônios e a sobrecarga mecânica imposta na sínfise, que gradualmente dá lugar ao ligamento interpúbico (Lip) e ao seu "relaxamento" no final da prenhez permitem a passagem da prole pelo canal do parto. Tais modificações oferecem oportunidade para estudo de remodelação de tecidos semelhantes às que ocorrem nas disfunções e distopias do assoalho pélvico feminino. Estudaram-se características morfológicas, imunohistoquímica das proteínas Galectina-3(GAL3) e CartilageOligomericProtein Matrix (COMP) e o comportamento biomecânico, na SP de camundongos fêmeas adultas jovens, durante a primeira prenhez e após o parto por meio de técnicas histológicas convencionais, imunohistoquímica, microscopia de luz, eletrônica de transmissão e varredura. Nas análises da organização fibrilar utilizou-se transformada rápida de Fourier (FFT) e do comportamento biomecânico ensaio destrutivo de tração uniaxial em máquina de testes universal com velocidade constante e força progressiva nas SP/Lip de camundongos C57BL6 grupos: (NP-controle), 12, 15 e 19 dias (d) após a verificação do plug vaginal e no 30, 50 e 100dias após o parto (dpp). No ensaio de tração uniaxial, a força máxima necessária para o início da ruptura do tecido diminuiu no decorrer da prenhez, sendo o menor valor medido no dia do parto, aumentou a partir deste dia, e no 10dpp retornou a valores próximos aosdos animais NP. A energia total de ruptura (ETR) diminuiu no 12d e a partir de 15d aumentou até o 5dpp, no 10dpp, diminuiu porém se manteve menor que o NP. Na Imunolocalização das proteínas COMP e GAL3 foram detectadas em todos os grupos, com variações no tipo celular e na localização. A morfologia bicorne do útero de camundongos e o peso do útero com os filhotes alteram os estímulos mecânicos nos tecidos interpúbicos e contribuem para sua remodelação. No 3dpp, quando os estímulos mecânicos foram abruptamente retirados no parto, observaram-se organelas compostas por microtúbulos semelhante a cílio solitário não móvel, citado como organela mecanosensorial. O comportamento biomecânico dos tecidos interpúbicos durante a prenhez e após o parto foi coerente com a histoarquitetura destes e a imunolocalização das proteínas COMP e GAL-3, à medida que o comportamento biomecânico dos tecidos se modifica são indicativos que essas proteínas estão envolvidas no remodelamento de transições de elementos ósseos e ligamentares e fibrocatilaginosas durante a prenhez e após o parto. Este remodelamento que proporciona afastamento de ossos púbicos e a rápida recuperação que se inicia pós-parto, oferece suporte ao canal de parto de animais que possuem útero bicorne a exemplo do camundongo, morcego e cobaia / Abstract: In mice, the pubic symphysis (PS) is metabolically active during pregnancy. Adaptations orchestrated by hormones and mechanical overload that the symphysis goes through during this period, which gradually gives place to an interpubic ligament (IpL) and the relaxation at the end of pregnancy, allows the passage of offspring through the birth canal. Such changes provide an opportunity to study remodeling of tissues such as those that occur in disorders and dystopias of the female pelvic floor. We studied morphological, immunohistochemical analysis of galectin-3 (GAL3) and Cartilage Oligomeric Matrix Protein (COMP) proteins and the biomechanical behavior in young adult females PS mice during first pregnancy and postpartum (dpp) through conventional histological techniques, immunohistochemistry and light,transmition and scanning electron microscopies. In analyzes of fibrillar organization we used fast Fourier transform and the biomechanical behavior destructive tensile testing in a universal testing machine with constant speed and progressive force in the PS/IpL C57BL6 mice groups: (NP-control), 12, 15 and 19 days (d) after checking the vaginal plug and 3th, 5th and 10thpp. In tensile testing the maximum force required to initiate the rupture of the tissue decreased in the course of pregnancy, with the lowest value measured at day of birth, increasing from this day on and at the 10dpp returned to the NP individual¿s value.The total rupture energy (TRE) decreasesat d12 and increased from d15 until 5dpp, decreasing at the 10dpp but remained lower than the NP. Immunolocalization of COMP and GAL3 proteins were detected in all groups, with variations in cell type and location. The bicornuate uterus morphology of the mice and the weight of the uterus with cubs alter the mechanical stimuli in interpubic tissues, contribute to its remodeling. In 3dpp when mechanical stimuli were abruptly removed at birth. It was observed organelles consisting of microtubules that were similar to a solitary cilium quoted as mechanosensory organelle.The biomechanical behavior of interpubic tissues during pregnancy and after delivery was consistent with the histoarchitecture and immunolocalization of COMP and GAL-3 protein, as the biomechanical behavior of the tissue changes are indicative that these proteins are involved in the remodeling of transitions bony and ligamentous elements and fibrocartilaginous during pregnancy and after childbirth. This remodeling that provides removal of pubic bones and a quick postpartum recovery, offers birth canal support of animals that have bicornuate uterus such as the mouse, guinea pig and bat / Doutorado / Biologia Tecidual / Doutora em Biologia Celular e Estrutural

Une série de composant hybride basée sur réactives polyédriques oligomères silsesquioxane (POSS) precusors et ses copolymères réactifs de PGMA ont été synthétisés et utilisés pour nanobuild en époxy. POSS réactifs et de copolymères en dispersion dans la matrice homogène dans, au délà de POSS-POSS interaction, ce qui a entraîné la séparation de phase macroscopique. Les nanocomposites obtenus ont été analysés par microscopie électronique à balayage, microscopie électronique à transmission, diffusion des rayons X et l'analyse mécanique dynamique. Un analogue de POSS (notée POSSMOCA) a été synthétisé par réaction d'addition, qui a réactive liaison groupe amino dans le réseau époxy et d'améliorer la stabilité thermique, en raison du silicium, d'azote et un atome d'halogène structurel. Époxy / polyédriques silsesquioxanes oligomères (POSS) composites hybrides ont été préparés à partir de pré-réaction entre l'éther de silanol POSS-OH et diglycidylique trifonctionnel de bisphénol A (DGEBA) par l'intermédiaire du silanol et un groupe oxiranne. Réactif POSS-PGMA a été polymérisé par polymérisation par transfert de réversible par addition-fragmentation. Il est facile à queue de la compatibilité du copolymère séquencé époxyde avec une matrice de l'étape de croissance-polymérisé, pour former par réaction avec nanostructure segements PGMA. Dans le cas d'inertes POSS-PMMA copolymères modifiés époxy, topologie de copolymère défini la morphologie finale et l'interaction entre époxy et entre eux, en raison de la liaison hydrogène directionnelle à effet de dilution. Tg de conversion époxyde différente, obéi de Gordon-Taylor équation et l'équation Kwei, k qui reflète l'interaction de modificateur et les oligomères DGEBA / MEDA et époxy / amine, était cohérente de la rhéologie et les résultats dynamiques. / A series of hybrid component based on reactive polyhedral oligomeric silsesquioxane(POSS) precusors and its reactive copolymers of PGMA were synthesized and utilized to nanobuild in epoxy. Reactive POSS and copolymer dispersed in homogenous in matrix, overcomed POSS-POSS interaction, which resulted in macroscale phase separation. The nanocomposites obtained were analyzed by Scanning electron microscopy, Transmission electron microscopy, X-ray scattering and dynamic mechanical. An analogue of POSS (denoted as POSSMOCA) was synthesized via addition reaction, which had reactive amino group bonding into epoxy network and improved the thermostability, because of the structural silicon, nitrogen and halogen. Epoxy/polyhedral oligomeric silsesquioxanes (POSS) hybrid composites were prepared from prereaction between trifunctional silanol POSS-OH and diglycidyl ether of bisphenol A (DGEBA) via silanol and the oxirane group. Reactive POSS-PGMA was polymerized via Reversible addition-fragmentation transfer polymerization. It was easy to tail the compatibility of the epoxide block copolymer with a step-growth polymerized matrix, to form nanostructure via reaction with PGMA segements. In the case of inert POSS-PMMA copolymers modified epoxy, topology of copolymer defined the final morphology and interaction between epoxy and them, because of directional hydrogen bonding and dilution effect. Tg of different epoxide conversion, obeyed of Gordon-Taylor equation and Kwei equation, k which reflected the interaction of modifier and DGEBA/MEDA and epoxy/amine oligomers, was consistent of the rheology and dynamic results.

No description available.