Made available in DSpace on 2017-07-21T20:42:44Z (GMT). No. of bitstreams: 1 Volnei Patel.pdf: 2182418 bytes, checksum: 0c02f090d39438a33dbc14bd153a4062 (MD5) Previous issue date: 2011-12-09 / In this work, blends of PEBD/m-PELBD with typical applications in the area of packaging films were studied. Thermal and rheological properties of blends of PEBD/m-PELBD were analyzed in the proportions of 80/20; 75/25; 70/30; 65/35;60/40, as well as the pure polymers. The samples were processed in single and twin screw extruders, thus allowing the evaluation of the influence of homogenization on the thermal and rheological properties. The effect of variations of the compositions of the blends on thermal properties was analyzed using the Differential Scanning Calorimetry technique (DSC), and the effect of variation in the rheology of the blends was analyzed in parallel plate and capillary rheometer for the various compositions and at different temperatures. The results obtained from the thermal analysis showed no variations in the melting and crystallization temperatures with variation of the composition, and the pure m-PELBD presented a melting temperature of 108ºC and PEBD 105ºC. The rheological analysis showed the high influence of PEBD in viscosity at low shear rates, presenting high viscosity. However, as of 100 1/s the reversal of the viscosity curves is observed,where m-PELBD has more influence. By means of rheological analysis, the phase behavior of the blends was investigated, which proved insoluble in all compositions in the molten state. However, due to the close proximity of the values of the melting temperature of the pure components, it was not possible to identify the expected second melting peak in the thermal analysis. Comparing the thermal and rheological results of the processed blends in the extruders of single and twin screws, no significant variations were observed. The thermal and rheological results obtained in this study show that possible small variations in composition during the feed dispensing process in the extruder would not generate significant instabilities in the process. / No presente trabalho foram estudadas blendas de PEBD/m-PELBD com aplicações típicas na área de filmes para embalagens. Foram analisadas as propriedades térmicas e reológicas das blendas de PEBD/m-PELBD nas proporções 80/20; 75/25; 70/30; 65/35; 60/40, bem como dos polímeros puros. As amostras foram processadas em extrusoras mono e dupla rosca, desta forma possibilitando avaliar a influencia da homogeneização nas propriedades térmicas e reológicas. O efeito das variações das composições das blendas nas propriedades térmicas foi analisado através da técnica de calorimetria exploratória diferencial (DSC), e os efeitos das variações na reologia da blenda foram analisados em reômetro de placa paralelas e capilar para as diversas composições e em diferentes temperaturas. Os resultados obtidos nas analises térmicas não apresentaram variações nas temperaturas de fusão e cristalização, com variação da composição, sendo que o m-PELBD puro apresentou uma temperatura de fusão de 108ºC, e o PEBD 105ºC. As analises reológicas demonstraram à alta influência do PEBD na viscosidade em baixas taxas de cisalhamento, apresentando viscosidade elevada. Porém, a partir de 100 1/s observa-se inversão das curvas de viscosidade, onde o m-PELBD influencia mais. Através de análises reológicas foi investigado o comportamento de fase das blendas, a qual se mostrou imiscível em todas as composições no estado fundido. Entretanto, devido à grande proximidade dos valores de temperatura de fusão dos componentes puros, na analise térmica não foi possível identificar o segundo pico de fusão esperado. Comparando os resultados reológicos e térmicos das blendas processadas em extrusora de rosca simples e dupla rosca, não foram observadas variações significativas. Os resultados térmicos e reológicos obtidos no presente estudos mostram que possíveis pequenas oscilações de composição durante o processo de dosagem na alimentação da extrusora não gerariam instabilidades significativas no processo.

Made available in DSpace on 2014-12-17T15:42:08Z (GMT). No. of bitstreams: 1 EliasJL_DISSERT.pdf: 3301731 bytes, checksum: ed73b5da4a7dcfb4e0f473a7c83986b2 (MD5) Previous issue date: 2013-05-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The study of polymer blends has been an alternative method in the search field of new materials for obtaining materials with improved properties. In this work blends of poly(methyl methacrylate) (PMMA) and poly(ethylene oxide) (PEO) doped with titanium dioxide (TiO2) were studied. The PEO is a polymer semicrystalline structure varying between, 70 and 84% crystallinity, while the PMMA exhibits behavior amorphous in their structure. The use of TiO2 is related to corrosion-resistant of titanium as well as good heat transfer and other characteristics. The study of these polymer blends doped TiO2 gives the properties junction organic (polymer) and inorganic (oxide) which leads to modification of the properties of the resultant material. The blends were doped TiO2 (POE/PMMA/TiO2) in different proportions of the PMMA with the PEO and TiO2 fixed. The ratios were: 90/10/0,1; 85/15/0, 1; 80/20/0,1, 75/25/0,1 and 70/30/0,1. The resulting material was obtained in powder form and being characterized by Fourier Transformed Infrared (FTIR) Spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and Electrochemical Impedance Spectroscopy (EIS). The infrared spectra (IR) for the blends in different ratios showed a band at 1744 cm-1, characteristic of the C=O stretching, which increases in intensity with increasing PMMA composition, while in the spectrum of pure PEO this band is absent. This may suggest that the interaction is occurring between the polymers. In the micrographs of the blends also observed change in their surfaces with variation of the composition of PMMA, contributing to the change of the electrical properties of the material. The EIS data showed that the material exhibited conductivity of the order of 10-6 S.cm-1. The blend in the ratio B2(85/15/0, 1) showed better conductivity, σ = 1.56 x 10-6 S.cm-1. It was observed that the diffusion coefficient for the blends, B5(70/30/0, 1) was the largest, 1.07 x 10-6 m2.s-1. The XRD data showing that, with the variation in the composition of the PMMA blend crystallinity of the material is decreased reaching a minimum B3(80/20/0,1), and then increases again. Thermal analysis suggests that blends made from the material obtained can be applied at room temperature / O estudo de blendas polim?ricas tem sido um m?todo alternativo no campo de pesquisa de novos materiais para obten??o de materiais com melhores propriedades. Neste trabalho blendas de poli(metacrilato de metila) (PMMA) e poli(?xido de etileno) (POE) dopadas com di?xido de tit?nio (TiO2) foram estudadas. O POE ? um pol?mero de estrutura semicristalina com varia??o entre, 70 e 84% de cristalinidade, enquanto o PMMA apresenta comportamento amorfo em sua estrutura. O uso do TiO2 est? relacionado ? alta resist?ncia a corros?o do tit?nio, assim como a boa transfer?ncia de calor, al?m de outras caracter?sticas. Uma das suas aplica??es ? a fotocat?lise. O estudo destas blendas polim?ricas dopadas com TiO2 proporciona a jun??o das propriedades org?nica (pol?meros) e inorg?nica (?xido), o que leva a modifica??o das propriedades do material resultante. As blendas foram dopadas com TiO2 (POE/PMMA/TiO2) em diferentes propor??es do POE e PMMA com o TiO2 fixo. As propor??es foram: 90/10/0,1; 85/15/0,1; 80/20/0,1; 75/25/0,1 e 70/30/0,1. O material resultante obtido foi em forma de p? sendo caracterizado por Espectroscopia de Infravermelho por Transformada de Fourier (FTIR), Microscopia de Varredura Eletr?nica (MEV), Difra??o de Raios X (DRX), Termogravimetria (TG/DTG) e Espectroscopia de Imped?ncia Eletroqu?mica (EIE). Os espectros de infravermelho (IV) para as blendas em diferentes propor??es apresentaram uma banda em 1744 cm-1, caracter?stica do estiramento C=O, que aumenta de intensidade com o aumento da composi??o do PMMA, enquanto no espectro do POE puro esta banda est? ausente. Isto pode sugerir que est? ocorrendo ? intera??o entre os pol?meros. Nas micrografias das blendas, tamb?m, observa-se mudan?a em suas superf?cies com a varia??o da composi??o do PMMA o que pode contribuir na mudan?a das propriedades el?tricas do material. Os dados de EIE mostraram que o material apresentou condutividade da ordem de 10-6 S.cm-1. A blenda na propor??o B2(85/15/0,1) apresentou melhor condutividade, σ = 1,56 x 10-6 S.cm-1. Observou-se que o coeficiente de difus?o para as blendas, a B5(70/30/0,1) foi o maior, 1,07 x 10-6 m2.s-1. Os dados de DRX mostram que, com a varia??o na composi??o de PMMA na blenda a cristalinidade do material vai diminuindo atingindo um m?nimo em B3(80/20/0,1) e, ent?o, volta a aumentar. An?lise t?rmica realizada das blendas sugere que o material obtido pode ser aplicado em temperatura ambiente

Le poly(1,3-dioxolanne) (PDOL) est un polymère semi-cristallin présentant à l’état solide quatre morphologies différentes (Phases I, IIa, IIb et III). Les transformations d'une phase à l'autre ont été suivies par microscopie optique polarisée (MOP) et microscopie à force atomique (AFM) en fonction de la température de cristallisation et de la masse molaire. La Phase I présente une morphologie sphérolitique tandis que la Phase IIa peut croître à partir de la Phase I ou spontanément. De façon inattendue, la Phase IIa, devient très biréfringente et cette nouvelle morphologie est appelée Phase IIb. Quand la transformation IIa-IIb est terminée, une nouvelle phase, la Phase III, croît à partir de la Phase IIb. La Phase III n'a jamais été observée sans la présence de Phase IIb; en outre, la Phase IIb remplace toujours la Phase IIa. Ce phénomène est appelé germination croisée. La mesure de la température de fusion des phases par MOP a permis d’établir leur stabilité relative: IIb > III >IIa. La vitesse de croissance (G) des sphérolites a été mesurée sur une plage de températures de 10,0 à 24,0 °C et montre une grande dépendance avec la masse molaire. Ces mesures ont révélé l’existence d’une masse molaire critique, autour de 5000 g.mol-1, en-dessous de laquelle nous avons observé GIIa > GIII et au-dessus de laquelle la relation est inversée avec GIII > GIIa. Finalement, nous avons exploré l’influence de l’ajout d’un deuxième polymère amorphe sur l’évolution des phases optiques dans des mélanges PDOL-PMMA, PDOL-PVC et PDOL-PVAc. Nous avons observé les mêmes transitions de phases que pour le PDOL pur et un certain degré de compatibilité dans le cas du PDOL-PMMA et du PDOL-PVC. / Poly(1,3-dioxolan) (PDOL) is a semi-crystalline polymer exhibiting in the solid state four different morphologies (Phases I, IIa, IIb and III). Transformations from one phase to another were followed by Polarized Optical Microscopy (POM) and Atomic Force Microscopy (AFM) as a function of crystallization temperature and molecular weight. Phase I shows a spherulitic morphology whereas Phase IIa normally grows radially from Phase I but it can also occur in the absence of Phase I. Its birefringence depends on the molecular weight of PDOL. Unexpectedly, at one point during the crystallization of Phase IIa, at constant temperature, it becomes highly birefringent, and this new morphology is called Phase IIb. When the transformation is completed, a new phase, Phase III, grows radially from Phase IIb; Phase III has never been observed without the presence of Phase IIb. Similarly, Phase IIb always replaces Phase IIa. This phenomenon is called cross-nucleation. The relative stability of the phases has been established as IIb > III >IIa. The growth rate of polymer spherulites was measured over a range of temperatures, from 10.0 to 24.0 °C, and showed remarkable molecular weight dependence. We found a critical molecular weight, around 5000 g.mol-1, below which the growth rate of Phase IIa is slower than that of Phase III but, at higher molecular weight, the trend is reversed. Finally, we explored the influence of the addition of a second amorphous polymer on the evolution of optical phases in some blends: PDOL-PMMA, PDOL-PVC and PDOL-PVAc. We found the same phase transformations as with pure PDOL and some degree of compatibility for the PMMA-PDOL and PDOL-PVC blends.

Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-09-12T20:11:13Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) regina_inez_souza.pdf: 2322505 bytes, checksum: fb22e286692f3f78b323a1aa5767c86b (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-09-18T13:03:41Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) regina_inez_souza.pdf: 2322505 bytes, checksum: fb22e286692f3f78b323a1aa5767c86b (MD5) / Made available in DSpace on 2017-09-18T13:03:41Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) regina_inez_souza.pdf: 2322505 bytes, checksum: fb22e286692f3f78b323a1aa5767c86b (MD5) Previous issue date: 2017 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Na ind?stria farmac?utica, os pol?meros s?o bastante utilizados em sistemas para libera??o controlada de f?rmacos, por serem capazes de liber?-los efetivamente no local alvo, aumentando os benef?cios terap?uticos e minimizando os efeitos colaterais. Entre os pol?meros utilizados para essa finalidade, tem-se o poli(3-hidroxibutirato) (PHB) pertencente a classe dos poli(hidroxialcanoatos), sendo um pol?mero de origem microbiana, que destacase por ser biorreabsorv?vel e biocompat?vel. Quando utilizado em misturas f?sicas com outros pol?meros, as denominadas blendas, modifica-se propriedades f?sicas, mec?nicas e biol?gicas do PHB para aumentar sua aplicabilidade. Nesse sentido, o propilenoglicol (PPG) foi utilizado para prepara??o de blendas PHBPPG (90/10). O objetivo do trabalho foi preparar e estudar filmes polim?ricos constitu?dos por PHB e PHBPPG (90/10) contendo 1% e 5% de Snitrosoglutationa (GSNO), um doador de ?xido n?trico (NO) bem como sintetizar o f?rmaco e avaliar sua estabilidade ap?s armazenamento a 23?C, 4?C e -18?C durante 90 dias por an?lise t?rmica e por espectroscopia na regi?o do infravermelho. Os filmes obtidos contendo GSNO foram caracterizados por an?lise t?rmica, espectroscopia no infravermelho e avaliou-se o perfil de libera??o in vitro dos mesmos. A citotoxicidade dos extratos das matrizes constitu?das somente por PHB e PHBPPG (90/10) foi avaliada sobre c?lulas mononucleares do sangue perif?rico (PBMC) e leuc?citos totais pelo m?todo de exclus?o com azul de Tripan e sobre hem?cias pela avalia??o da atividade hemol?tica. Os resultados da an?lise t?rmica e infravermelho mostraram que a melhor forma de armazenamento de GSNO ? em 4?C e -18?C. As matrizes polim?ricas de PHB e da blenda PHBPPG (90/10) contendo 1% e 5% de GSNO, avaliadas por an?lise t?rmica foram capazes de liberar NO e apresentaram-se mais est?veis termicamente quando comparados aos filmes de PHB e da blenda sem o f?rmaco. O perfil de libera??o dos filmes de PHB e da blenda PHBPPG (90/10) mostrou que h? uma libera??o r?pida inicial de GSNO nas 24 horas iniciais seguido por um padr?o de libera??o controlada no per?odo de 1 a 8 dias para os filmes contendo 5% de GSNO, sendo o filme da blenda PHBPPG (90/10) contendo 5% de f?rmaco, o que apresentou maior porcentagem de libera??o no per?odo avaliado. Extratos provenientes dos filmes de PHB e da blenda PHBPPG (90/10) n?o apresentaram car?ter citot?xico por n?o induzirem hem?lise das hem?cias e n?o reduzirem a viabilidade celular de PBMCs e leuc?citos totais. As blendas desenvolvidas neste trabalho possuem a capacidade de libera??o controlada e in situ de ?xido n?trico, e possuem aplica??o potencial, por exemplo, no revestimento de stents coronarianos para preven??o da restenose p?s-angioplastia. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Ci?ncias Farmac?uticas, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Polymers are widely used for controlled drug release systems improving the therapeutic benefits and minimizing side effects by the pharmaceutical industry due their capability of releasing it effectively at the target site. Among the polymers used for this purpose there is poly(3-hydroxybutyrate, PHB), a polymer from microbial origin of the poly(hydroxyalkanoate) class that is both bioresorbable and biocompatible. When used as a physical blends with other polymers several properties of PHB (physical, mechanical and biological) could be modified to increase their applicability. To produce blends with PHB the propyleneglycol (PPG) was used to prepare PHBPPG blends (90/10). The aim of this work was to prepare and study polymeric films composed by PHB and PHBPPG (90/10) containing 1% and 5% S-nitrosoglutathione (GSNO), a nitric oxide (NO) donor. The GSNO was synthesized and had its stability evaluated after storage at 23 ? C, 4 ? C and -18 ? C for 90 days by thermal analysis and infrared spectroscopy. The polymer materials containing GSNO were characterized by thermal analysis, infrared spectroscopy and also their drug release capability was evaluated. The cytotoxicity of matrices constituted by PHB and PHBPPG (90/10) was evaluated on peripheral blood mononuclear cells (PBMC) and total leukocytes by the exclusion method with Tripan blue and on red blood cells by the evaluation of hemolytic activity. The thermal and infrared analysis showed that the best form of GSNO storage is at 4 ? C and -18 ? C. Polymeric matrices of PHB and PHBPPG (90/10) containing 1% and 5% of GSNO, were able to release NO and were more thermally stable when compared to PHB and blends without the drug. The release profile of the PHB and PHBPPG blends (90/10) showed an initial fast release of GSNO at the initial 24 hours followed by a controlled release pattern in the period of 1 to 8 days for materials containing 5% of GSNO. The PHBPPG (90/10) blends containing 5% of drug presented the highest percentage of release in the evaluated period. The PHB and PHBPPG (90/10) blends did not present cytotoxic effects. The studied materials did not induced hemolysis of the red blood cells and did not reduced the cellular viability of PBMCs and total leukocytes. The developed blends are capable to exert the in situ controlled-release of nitric oxide and can potentially be used for example to coat coronary stents and thus help to prevent post-angioplasty restenosis.

Le travail de thèse présenté dans ce manuscrit a consisté à mettre en avant un nouveau procédé de mélange des polymères développé au LIPHT lors de la mise en oeuvre de mélanges PP/EPDM réticulés dynamiquement et chargés à base de graphène. Ce nouveau mélangeur, appelé RMX®, se distingue de la plupart des mélangeurs existants par la présence d’écoulements élongationnels forts, la possibilité de mouler directement des éprouvettes à l’issue de l’étape de mélange ainsi qu’une étanchéité aux gaz et aux liquides. Après une optimisation des conditions opératoires de ce mélangeur, nous avons pu évaluer quantitativement l’efficacité du mélange dispersif par analyse numérique de tailles de particules d’EPDM dispersées dans une matrice PP. Le RMX® permet d’obtenir une dispersion fine (~ 1 μm) pour des énergies spécifiques et des temps de mélange inférieurs aux procédés existants. Des tailles significativement réduites ont été obtenues pour des mélanges présentant un rapport de viscosité élevé (p > 1). Ces résultats ont été attribués à la combinaison de taux de déformation en cisaillement élevés dans le canal de l’élément de mélange avec des taux de déformation en élongation majoritaires en entrée/sortie de ce dernier. L’impact des écoulements élongationnels sur l’intervalle de (co)-continuité de mélanges PP/EPDM a ensuite été étudié. Un décalage de la percolation de la phase dispersée (EPDM) vers les hautes concentrations ainsi qu’une borne supérieure de cet intervalle plus élevée ont ainsi pu être mis en évidence à l’aide de techniques complémentaires (MEB, extraction sélective de la phase EPDM, analyse rhéologique). Une procédure originale d’élaboration de matériaux TPV dans le RMX® a également été réalisée. La réticulation dynamique au moyen d’une résine phénolique d’un mélange PP/EPDM présentant une morphologie co-continue a été effectuée. Des taux d’insoluble proche de 100% ainsi que les propriétés élastiques des TPV formés ont permis de confirmer l’efficacité de cette étape de réticulation dans le RMX®. Une dernière étude a consisté à disperser une nanocharge graphitique lamellaire et conductrice (xGNPTM) dans une matrice PP. L’analyse par diffraction des rayons X, les seuils de percolation rhéologique et électrique obtenus autour de 7 et 8 wt% respectivement ainsi qu’un facteur de forme Af ~ 15 suggèrent une absence d’exfoliation ainsi qu’une agrégation importante des particules de xGNP. / A new mixing device (RMX®) based on elongational flows has been developed during this work. This device has specific technical features comparing to conventional mixers such as: variable mixing volume, direct molding of samples, air and water tightness. After an optimization of processing conditions, dispersive mixing efficiency was assessed on PP/EPDM blends by numerical analysis. Very fine dispersed morphologies were obtained for lower specific mixing energy and mixing times comparing to internal mixer (Haake Rheomix 600). Significantly reduced droplet sizes have been obtained for high-viscosity ratio blends (p > 1). These results indicate an enhanced droplet break-up mechanism in the RMX® which was attributed to the combination of high shear rates inside the mixing element and important elongational flows in the convergent/divergent zones. Impact of elongational flow mixing on the (co)-continuity interval of PP/EPDM blends was investigated. An important shift (~ 10 wt%) of the EPDM percolation threshold as well as a higher phase inversion concentration was observed. A combination of complementary techniques (SEM, selective extraction and rheological analysis) was successfully carried on in order to assess this (co)-continuity interval. Then, PP/EPDM blends with a co-continuous morphology were dynamically crosslinked in the RMX® using resole as a crosslinking agent. An original and specific procedure was developed for this purpose. Gel fraction close to 1 and significantly enhanced elastic properties after crosslinking confirmed the efficiency of this procedure. Finally, the dispersion of lamellar and conductive nanofillers (xGNPTM) in a polypropylene matrix was studied. Microstructural characterization by XRD and optical microscopy, rheological and electrical percolation thresholds (7 and 8 wt% of xGNP respectively) and corresponding aspect ratios (Af ~ 15) have shown no evidence of exfoliation.

The steep rise in the contamination of natural water sources, has led to an increasing demand for alternate solutions to cater safe drinking water to mankind. Water treatment by separation technology utilizes semipermeable membranes to filter the contaminants commonly present in potable water. In this context, the current work focuses on the development of membranes that are affordable, exhibit chemical resistance and can be developed at industrial scale. By blending two immiscible polymers like polyethylene (PE) and polyethylene oxide (PEO), different morphologies can be generated and porous structures can be developed by selectively etching the water soluble phase (PEO). Microorganisms in the feed stream often tend to foul the membrane by forming biofilms on the surface that tends to increase the resistance offered by the membrane. Therefore, preventing this biofilm is a key challenge in this field and can be overcome by use of functional group or materials that prevent the attachment or growth of microorganisms on the surface, while maintaining a good permeation rate of water. This thesis entitled “Porous Antibacterial Membranes Derived from Polyethylene (PE)/Polyethylene oxide (PEO) Blends and Engineered Nanoparticles” systematically studies the various morphologies generated by melt blending polyethylene (PE)/polyethylene oxide (PEO) in presence and absence of a compatibilizer (maleated PE). Porous structures are developed by selectively etching PEO from the blends and the nature of the pores, which is dependent on the blend composition, is assessed by tomography. The potential of these membranes are discussed for water purification application. Further, various modifications either on the surface or in the bulk have been systematically studied. For instance, incorporation of biocidal agents like graphene oxide (GO) and modified GO in the matrix and coating/grafting of membrane surface with biocidal agents like silver (Ag), GO for preventing the biofouling and to meet the specific requirements for safe drinking water. The thesis consists of ten chapters. Chapter 1 is a review on polymer blends for membrane applications. This chapter covers the fundamentals of polymer blends in transport processes and compares the merits and demerits of the conventional methods. This chapter mainly covers the melting blending technique and the optimizing parameters for obtaining a desired morphology. Further, the various methodologies for stabilization of the morphology against post processing operation have been discussed. The various methodologies for designing membranes (for water purification) that suppress or inhibit the bacterial activity on the membrane surfaces have been discussed elaborately. Chapter 2 outlines the materials, experimental set-up and procedures employed. Chapter 3 focuses on the morphologies that are developed during the blending of PE/PEO with varying weight ratios. The morphologies developed are supported by SEM analysis. The factors governing the localization of particles in PE/PEO blends are discussed in detail. The gradient in morphology obtained during post processing operations is highlighted. Based on the type of morphologies obtained, the thesis is divided into two parts as (I) membranes designed using matrix droplet type of morphology and (II) membranes designed using co-continuous morphology. Part I consists of four chapters that involves the development of membranes utilizing matrix droplet morphology. Chapter 4 focuses on the development of morphology, the length scales of which are smaller than a bacterial cell. This ensures sieving of the contaminants that are commonly present in the drinking water though the surface of the membranes may not be antibiofouling. Thus a passive strategy of antibiofouling has been employed by blending biocidal agents like GO and amine modified GO during melt mixing. The antibacterial mechanism and its effect on bacterial activity have been thoroughly studied. Chapter 5 focuses on modification of membrane by incorporating silver decorated GO in the bulk. The effect of incorporation of these particles and their effect on bacterial activity have been discussed systematically. Chapter 6 emphasizes on the surface coating of membrane with chitosan to enhance the antibacterial activity and antibiofouling. Chapter 7 focuses on the development of membrane with pore sizes that are larger than a bacterial cell. These membranes are grafted with antibacterial polymers like polyethylene imine (PEI) and Ag to achieve antibacterial and antibiofouling surface. The possible mechanism of bacterial inactivity is described and the leaching of Ag from the membranes has been discussed. Part II of the thesis focuses on the development of co-continuous morphology in PE/PEO blends and has been assessed using 3D tomography. Chapter 8 describes the development of co-continuous morphology in PE/PEO blend. 2D and 3D micrographs have been corroborated for understanding the morphology evolution during post processing operation like remelting or hot-pressing. The blend has been strategically compatibilized to arrest the morphology and retain the co-continuity in the blends. GO was anchored onto the surface of the membrane by rendering suitable surface active groups. The antibiofouling and bacterial inhibition was studied in detail. The effect of anchoring GO on the membrane surface has been discussed with respect to their membrane performance and its antibacterial activity. Chapter 9 discusses the development of membranes using PE based Ionomer (Surlyn) and PEO. The Ionomer provided active sites for reducing silver nitrate directly onto the surface of PE to render antibacterial surface which otherwise requires a two-step protocol in the case of inert PE. The effect of coating Ag on the membrane performance and its antibacterial activity is elaborated. Chapter 10 sums up the major conclusions from each chapter and highlights the outcome of the work.

O Poli(ácido láctico) (PLA) é um polímero biodegradável, biocompatível e biorreabsorvível proveniente de fontes renováveis. Constitui uma excelente alternativa sustentável para os polímeros provenientes de petróleo, atualmente dominantes no mercado industrial. Porém, apresenta baixas ductilidade e tenacidade como principais limitações mecânicas. Um dos métodos mais utilizados para modificar essas propriedades é a mistura mecânica do PLA com polímeros flexíveis, como a poli(ε-caprolactona) (PCL). Entretanto, o alto desempenho mecânico de blendas PLA/PCL é difícil de ser atingido devido à imiscibilidade dos polímeros. A melhoria de propriedades, neste caso, só é conseguida por meio de compatibilização. Este trabalho visa avaliar o efeito compatibilizante do copolímero tribloco de baixo peso molecular derivado de ε-caprolactona e tetrametileno éter glicol disponível comercialmente em blendas imiscíveis de PLA com PCL. Blendas binárias e ternárias foram preparadas por mistura mecânica no estado fundido via processo de extrusão em rosca simples. O teor de PLA nas blendas variou em 75, 50 e 25% (% em massa) e a concentração do copolímero em 0, 1,5, 3 e 5% (% em massa). A avaliação morfológica e o comportamento térmico e mecânico das blendas PLA/PCL foram realizados por microscopia eletrônica de varredura (MEV), calorimetria exploratória diferencial (DSC), análise térmica dinâmico-mecânica (DMTA) e ensaios mecânicos de tração, flexão e impacto Izod. O efeito compatibilizante do copolímero foi mais bem observado nas blendas com 75% (% em massa) de PLA, enquanto que nas blendas com 50% e 25% (% em massa) de PLA esse efeito não foi tão evidente. Os resultados obtidos no ensaio de tração mostraram que com o aumento do teor de compatibilizante, a tensão no escoamento, a tensão na ruptura e o módulo elástico das blendas com 75% (% em massa) de PLA se mantiveram praticamente constantes, enquanto que a deformação na ruptura evoluiu de 20% na blenda com 1,5% (% em massa) de copolímero para 84% na blenda com 5% (% em massa) de copolímero. As análises morfológicas indicaram que o copolímero em bloco agiu na interface PLA/PCL, melhorando sua adesão. Esse resultado foi reforçado pelas análises térmicas, onde foi constatado que as Tg\'s e Tm\'s do PLA e do PCL nas blendas não apresentaram alterações, o que indica que o copolímero encontra-se na região interfacial da blenda. A resistência ao impacto Izod com entalhe, propriedade mecânica utilizada nesse trabalho como uma medida da tenacidade, da blenda PLA75C5 alcançou 42 J/m, valor significativamente superior ao determinado para o PLA puro, por volta de 28 J/m. Esses resultados mostram claramente que o copolímero tribloco derivado de ε-caprolactona e tetrametileno éter glicol é um eficiente compatibilizante para blendas PLA/PCL. / The Poly (lactic acid) (PLA) is a biodegradable, biocompatible and bioabsorbable polymer derived from renewable sources. It is an excellent sustainable alternative to polymers derived from oil, currently dominating the industry. However, PLA has low ductility and poor toughness as main mechanical limitations. Mechanical mixing of PLA with flexible polymers, such as poly (ε-caprolactone) (PCL), is one of the most used methods to modify these properties. However, a high mechanical performance of PLA/PCL blends is difficult to achieve due to the immiscibility of the polymers. The improvement of properties in this case is achieved only by compatibilization. This study aims to evaluate compatibilizer effect of a low molecular weight tri-block copolymer derived from ε-caprolactone and tetramethylene ether glycol, commercially available, on immiscible blends of PLA with PCL. Binary and ternary blends were prepared by mechanical blending in melt state through a single screw extrusion. The content of PLA in the blends ranged in 75, 50 and 25 wt% and the concentration of copolymer in 0, 1.5, 3 and 5 wt%. The morphological evaluation and the thermal and mechanical behavior of PLA/PCL blends were performed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and tensile test, flexural and Izod impact. The compatibilizer effect of the copolymer was more clearly observed in the blends with 75 wt% PLA, whereas in blends with 50 wt% to 25 wt% of PLA this effect was not so evident. The results of the mechanical tests showed that with the increase of the compatibilizer content, the yield stress, the stress at break and the elastic modulus of the blends with 75% (wt%) remained practically constant, while the elongation at break evolved from 20% in the blend with 1.5 wt% of copolymer to 84% in the blend to with 5 wt% of copolymer. Morphological analysis indicated that the block copolymer acted in the PLA/PCL interface, improving adhesion. This results were reinforced by thermal analysis, where it was found that the Tg and Tm of PLA and PCL in the blends showed no change, indicating that the copolymer is in the interfacial region of the blend. The Izod impact strength (Notched Izod), mechanical properties used in this work as a measure of toughness, of the blend PLA75C5 reached 42 J/m, significantly higher than the determined for pure PLA, about 28 J/m. These results clearly show that the triblock copolymer derived from ε-caprolactone and tetramethylene ether glycol is a good compatibilizer for blends PLA/PCL because it acts at the interfacial region, promoting the adhesion between the phases.

Submitted by GIOVANNI BARRERA TORRES null (gbarrerat01@gmail.com) on 2017-08-04T04:24:40Z No. of bitstreams: 1 TESE VERSÃO FINAL Giovanni Barrera Torres.pdf: 6197644 bytes, checksum: d321626a0e947c39627bbfe43b7aaf87 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-08-04T19:37:47Z (GMT) No. of bitstreams: 1 torres_gb_dr_prud.pdf: 6197644 bytes, checksum: d321626a0e947c39627bbfe43b7aaf87 (MD5) / Made available in DSpace on 2017-08-04T19:37:47Z (GMT). No. of bitstreams: 1 torres_gb_dr_prud.pdf: 6197644 bytes, checksum: d321626a0e947c39627bbfe43b7aaf87 (MD5) Previous issue date: 2017-06-21 / Asociación Universitaria Iberoamericana de Postgrado (AIUP) / A presente pesquisa foi projetada para promover o desenvolvimento de compósitos poliméricos a partir da mistura de polietileno de baixa densidade (PEBD) com borracha natural (BN) reforçada com a cinza, resíduo da queima do bagaço, a cinza da cana de açúcar (CBC). Uma das propostas desta pesquisa foi direcionar uma aplicação ao resíduo, que é um material abundante e descartado, gerado no processo usual das usinas. A borracha natural empregada foi obtida a partir do látex de seringueira de Hevea Brasiliensis, Clone RRIM 600 muito cultivado no Brasil. A fim de se estudar separadamente a interação entre a CBC junto a BN e os agentes de vulcanização. Foi estudada numa primeira etapa: a mistura de borracha natural com a cinza de bagaço da cana até desenvolver uma mistura chamada de master, com boas propriedades de tensão e deformação. Foram produzidos compósitos elastoméricos aplicando agente silano como sistema de acoplamento. Numa segunda etapa o master compatibilizado foi misturado ao PEBD sem o uso de agentes de vulcanização; a finalidade destes compósitos foi de estudar a interação dos constituintes visando obter um compósito com o mínimo de agentes químicos e funcional para a indústria. Numa última etapa foram desenvolvidas blendas e compósitos termoplásticos vulcanizáveis (TPV); nesta etapa foram aplicados os agentes de vulcanização empregados na primeira etapa da pesquisa. As amostras foram estudadas por meio das técnicas de análises estruturais (FT-IR); físico-mecânicas (tensão e deformação; dinâmicas e mecânicas, DMA); térmicas (DSC e TG); dureza (Shore A). Foram obtidos resultados sobressalientes em comparação com as amostras sem agentes de vulcanização nas amostras com 50 % de master e 50 % de PEBD na resposta de elongação e tensão; a dureza acima do Shore A 85 obtida, foi produto da porcentagem da fase de PEBD presente nas amostras; nas análises térmicas foi possível observar degradação acima dos 160 oC resultando uma boa característica para aplicações industriais. Com os resultados obtidos tornou-se possível direcionar tanto a CBC como os compósitos para aplicações tecnológicas a fim de serem utilizados na fabricação de cabos de ferramentas, amortecedores, produtos para o lar, entre outros. / The present research was aimed to promote the development of polymeric composites from the mixture of low density polyethylene (LDPE) with natural rubber reinforced with ash, residue of the burning of sugarcane bagasse (SCB). One of the proposals of this research was to direct an application to the residue, which is an abundant and discarded material, generated in the usual process of the plants. The natural rubber used was obtained from rubber latex clone of Hevea Brasiliensis, Clone RRIM 600 widely cultivated in Brazil. In order to study separately the interaction between SCB with NR and vulcanization agents. It was developed in the first stage: the mixing of natural rubber with the sugarcane bagasse ash to develop a mixture called master, with good tensile and deformation properties. Elastomeric composites were produced by applying silane as a coupling agent. In a second stage the compatibilized master was mixed to the LDPE without the use of vulcanization agents; the purpose of these composites was to study the interaction of the constituents in order to obtain a composite with the minimum of chemical and functional agents for the industry. In the latter stage vulcanizable thermoplastic blends and thermoplastic composites were developed; In this stage the vulcanization agents used in the first stage of the research were applied. The samples were studied using structural analysis techniques (FT-IR); Physical-mechanical (tension and deformation, dynamic and mechanical, DMA); (DSC and TG); Hardness (Shore A). Sparing results were obtained in comparison with the samples without vulcanization agents in samples with 50 % of master and 50 % of LDPE in the strain and stress response; the hardness above Shore A 85, obtained was the product of the percentage of the LDPE phase present in the samples; In the thermal analyzes it was possible to observe degradation above 160 oC resulting in a good characteristic for industrial applications. With the results obtained, it became possible to target both SCB and composites for technological applications in order to be used in the manufacture of tool cables, shock absorbers, household products, among others. / AIUP: A0 185864

O objetivo deste trabalho foi a produção de blendas a partir de zeína e amido de milho, procurando unir de forma otimizada as propriedades dos polímeros e suas características de processabilidade e o entendimento da correlação estrutura-propriedades destas blendas. Misturas de amidolzeína foram preparadas nas proporções de 0/100, 10190, 20180, 30170, 50150, 80120 e 10010 massa/massa%, utilizando glicerol como plastificante nas proporções de 22, 30 e 40% em relação a massa total dos polímeros. As formulações foram processadas em um misturador interno, tipo Haake, conectado ao reômetro de torque a 160°C. As misturas obtidas foram moldadas por compressão a 160°C. As propriedades das blendas foram aliadas por ensaios de absorção de umidade, difração de raios X, ensaios mecânicos (tração), calorimetria exploratória diferencial (DSC), termogravimetria (TG), análise termo dinâmica-mecânica, microscopia eletrônica de varredura (MEV) e microscopia ótica. As blendas com 22% de glicerol foram avaliadas também quanto a biodegradabilidade, utilizando a técnica de biodegradação aeróbia. A adição da zeína facilitou o pmcessamento das misturas, conforme o observado durante o processamento no reômetro de torque. A presença da zeína não afeta a cristalinidade do amido nas blendas e não ocorre a formação de novas estruturas cristalinas devido a mistura. As blendas amidolzeína apresentaram menor estabilidade térmica que o amido termoplástico e zeína plastificada separadamente e a estabilidade térmica das blendas diminuiu com o aumento do teor de glicerol. As propriedades mecânicas das blendas foram dependentes do teor de zeína e de glicerol. A adição de zeína na lenda provocou aumento no módulo de elasticidade e na resistência a tração e diminuição da deformação , enquanto que o gliceml provocou diminuição em todas estas propriedades. As blendas apresentaram-se imiscíveis em todas as composições estudadas. A zeína plastificada mostrou biodegradação mais acentuada que o amido termoplástico e as blendas apresentaram biodegradação intermediária entre o amido e a zeína. / In this work were investigated blends from zein, which is a com protein, with com starch. The objective of this work was optimizing the polymers properties and their processing characteristics and looking for a structure-properties correlation of these blends. The mixtures of pure polymers and starchlzein blends were prepared using glycerol as plasticizer in a batch mixer connected to a torque rheometer. The zein content varied from 20 to 80% and three levels of glycerol were used, 22, 30 and 40 % of total starch plus zein weight, on a dry basis. The mixtures obtained were molded by compression at 160 OC. The blends were characterized by water absorption experiments, wide-angle X-ray diffraction, thermogravimetry (TG), differential scanning calorimetry (DSC), tensile test, dynamical mechanical thermal analysis (DMTA), scanning electron microscopy (SEM), optical microscopy. Additionally the biodegradability of starchtzein blends were evaluated by aerobic test. The torque behavior of the starchtzein blends shows that zein acts as a processing agent, reducing the melt viscosity of the mixture and facilitating the plasticization of starch. No evidence of the zein affecting the type or amount of crystal structure of thermoplastic starch was observed. The zein proved to be effective to reduce the water absorption of the blends. Mechanical properties of blends depends on the glycerol and zein contents. Young\'s modulus and ultimate tensile strength increase sharply with increasing zein content, while that the glycerol caused reduction on these properties. The blends were immiscible and phase invesion was observed. The results of biodegradation aerobic showed that after 45 days the zeína unfastened greater COz mass than the starch. This indicates that the zein biodegradation occurs more easily than the starch. The blends presented intermediate biodegradtion between the starch and the zein.

This study investigated the effect of chain extender epoxy based additive, Joncryl ADR 4368, on the rheological, thermal and mechanical properties of poly(lactic acid) with poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends in the blown films form. Compositions with 40% and 60% by weight PLA were selected for production of such blown films. These dispersed phase content was chosen because the literature does not present mechanical behavior studies of tubular film blends with high concentration of the dispersed phase. Rheological analysis in dynamic oscillatory regime showed the reaction of epoxy group with end chain in both polymers, and a higher reactivity of the chain extender with PLA. The films produced exhibited different morphologies according to the blend composition and chain extender content. Films containing 40% PLA presented the dispersed phase morphology in a fibrillar form; however in the presence of chain extender, the dispersed phase is presented as ellipsoids. This change in morphology resulted in a reduction in the mechanical properties of these films in tensile tests. Films containing 60% PLA had a coarse morphology with dispersed phase in the ribbons-like form. The addition of extender yielded a refinement of the dispersed phase morphology from ribbon to elongated fibril form, which is responsible for the mechanical properties improvement of these films. Despite the low adhesion between matrix and dispersed phase, the proper setting of the morphology of the blends as a function of additive content, allowed to produce films with mechanical properties quite different from each other. / Neste trabalho foi estudado o efeito do aditivo extensor de cadeia à base de epóxi, Joncryl ADR 4368, nas propriedades reológicas, térmicas e mecânicas de filmes tubulares de blendas de poli(ácido láctico) com poli(butileno adipato-co-tereftalato) (PLA/PBAT). Composições com 40% e 60% em peso de PLA foram selecionadas para produção destes filmes tubulares. Estes teores de fase dispersa foram escolhidos pelo fato da literatura não apresentar estudos de comportamento mecânico de filmes tubulares de blendas com alta concentração da fase dispersa. Análises reológicas em regime dinâmico oscilatório evidenciaram a reação do grupo epóxi com finais de cadeia de ambos os polímeros, e evidenciaram uma maior reatividade do extensor com o PLA. Os filmes produzidos apresentaram diferentes morfologias de acordo com a composição da blenda e o teor de extensor de cadeia adicionado. Filmes contendo 40% de PLA apresentaram uma morfologia da fase dispersa na forma fibrilar; já na presença do extensor, a fase dispersa se apresentou na forma de elipsóides. Esta mudança na morfologia acarretou em uma redução nas propriedades mecânicas destes filmes em ensaios de tração. Filmes contendo 60% de PLA apresentaram uma morfologia grosseira com a fase dispersa na forma de fitas. A adição do extensor proporcionou um refinamento na morfologia da fase dispersa com formação de fibrilas alongadas, responsável pelo ganho nas propriedades mecânicas destes filmes. Apesar da baixa adesão entre matriz e fase dispersa, o ajuste apropriado da morfologia das blendas, em função do teor de aditivo, possibilitou produzir filmes com propriedades mecânicas bastante diferenciadas entre si.