Orientador: Solange Cadore / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-13T13:12:41Z (GMT). No. of bitstreams: 1 Matoso_Erika_D.pdf: 946241 bytes, checksum: 56f70c56da8e0c3fb10d01d26c121fb7 (MD5) Previous issue date: 2009 / Resumo: Os polímeros são um grupo importante de materiais de engenharia pela sua facilidade de produção e uma larga faixa de propriedades e aplicações. O acetato de polivinila (PVAc) é produzido pela polimerização do acetato de vinila em presença de um catalisador. Suas principais aplicações estão na indústria de tintas, vernizes e adesivos. Neste trabalho foi desenvolvido um método de digestão de amostras de acetato de polivinila (látex base PVAc) em emulsão aquosa para determinação de As, B, Ba, Bi, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Sb, Se e Sn, utilizando a técnica de espectrometria de emissão ótica em plasma de argônio indutivamente acoplado (ICP OES). Foram testados diferentes procedimentos de digestão da amostra (calcinação, digestão ácida à baixa e à alta temperatura e digestão assistida por microondas em frasco fechado) com a finalidade de se obter o método mais exato, mais preciso, com maior sensibilidade e com um menor tempo. Os melhores resultados para a determinação dos elementos estudados em acetato de polivinila foram obtidos utilizando-se a digestão assistida por microondas em frasco fechado. Nas condições otimizadas, a solução após digestão apresentou 0,1% de CCR (conteúdo de carbono residual), as recuperações obtidas ficaram na faixa de 98 a 105% para o produto de base (PVAc), com desvio padrão relativo (RSD) na faixa de 1,0 a 5,1% e limites de quantificação entre 0,003 e 0,294 mg kg. A exatidão do método proposto foi avaliada, também, pela análise de material de referência certificado, com resultados considerados satisfatórios para a maioria dos elementos. A aplicação do método desenvolvido em amostras de cola com base PVAc mostrou valores abaixo do limite de quantificação (LOQ) para a maioria dos elementos analisados, com exceção de Fe, Cu, Cr e Ni. No entanto, para estes elementos, os valores encontrados estão abaixo daqueles recomendados pelas agências reguladoras. A determinação de Cu por GF AAS em amostras de PVAc, sem a etapa prévia de preparação de amostra, mostrou resultados satisfatórios de recuperação e uma maior sensibilidade, com limite de quantificação de 0,001 mg kg / Abstract: Polymers are an important group of engineering materials because they are easily produced and have many applications. Polyvinyl acetate is produced by polymerization of vinyl acetate in presence of a catalyst and finds numerous applications in the manufacture of emulsion paints, varnishes and adhesives. A digestion method for the determination of de As, B, Ba, Bi, Cd, Cr, Cu, Fe, Hg, Ni, Pb, Sb, Se e Sn by Inductively Coupled Argon Plasma Optical Emission Spectrometry (ICP OES) in samples of polyvinyl acetate water emulsions was developed. The sample was treated by different procedures in order to determine the best treatment. In this way, calcination, acid digestions at low and high temperature and digestion by microwave radiation were studied. The best results for the determination of elements in polyvinyl acetate were achieved using microwave digestion. Under optimum conditions, only 0.1% of total organic carbon (TOC) was found as residue and recoveries between 98 and 105% for base product (PVAc) with RSD between 1.0 and 5.1% and quantification limits between 0.003 and 0.294 mg kg were obtained. The accuracy was also evaluated analyzing certified reference materials with satisfactory results. The application of the developed method in PVAc glue samples showed lower results than quantification limits for most elements, except Fe, Cu, Cr and Ni. But the found values are lower than those recommended by regulation agencies. Cupper determination by GF AAS in PVAc samples without treatment showed good results for recoveries and better sensibility (quantification limit: 0,001 mg kg) / Doutorado / Quimica Analitica / Doutor em Ciências

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Plumeria rubra L. à uma planta laticÃfera pertencente à famÃlia Apocynaceae popularmente conhecida como Jasmim. Por apresentar flores vistosas e perfumadas, essa Ãrvore à comumente vista ornamentando praÃas e jardins residenciais dos grandes centros urbanos. Plantas laticÃferas sÃo assim denominadas por que produzem endogenamente um fluido de aspecto geralmente leitoso - o lÃtex - que à exsudado da planta quando esta sofre algum tipo de ferimento, seja por dano mecÃnico ou por ataque de predadores. O lÃtex à um material vegetal que tem sido alvo de estudos bioquÃmicos e farmacolÃgicos que mostram ser ele uma fonte promissora de compostos com potencial aplicaÃÃo biotecnolÃgica. No presente trabalho o lÃtex de P. rubra foi alvo de investigaÃÃes bioquÃmicas e biolÃgicas com Ãnfase na pesquisa de proteÃnas que pudessem apresentar alguma aÃÃo deletÃria contra insetos pragas agrÃcolas. Procedimentos laboratoriais que empregam centrifugaÃÃes e diÃlises permitiram o fracionamento do lÃtex em trÃs componentes distintos: borracha (BL), proteÃnas (PLPr) e molÃculas de baixa massa molecular (DL). A fraÃÃo PLPr foi alvo de caracterizaÃÃo bioquÃmica e enzimÃtica e foi utilizada em bioensaios com o caruncho do feijÃo-de-corda, Callosobruchus maculatus e com a mosca-das-frutas, Ceratitis capitata. O lÃtex Ãntegro e suas fraÃÃes foram utilizados em ensaios de repelÃncia da ovoposiÃÃo de C. maculatus e Zabrotes subfasciatus. A fraÃÃo BL à o componente majoritÃrio do lÃtex, 70 %, enquanto as fraÃÃes PLPr e DL constituem cerca de 15 % cada uma. O teor de proteÃnas solÃveis na fraÃÃo PLPr foi de 0,33 mg/mL. AnÃlises eletroforÃtica e espectromÃtricas revelaram a presenÃa de proteÃnas com massas moleculares que variaram de 12 a 117 kDa, com um mÃximo de proteÃnas com 26 kDa e pI<6,0. A caracterizaÃÃo enzimÃtica mostrou que as enzimas antioxidantes superÃxido dismutase e peroxidase foram detectadas na fraÃÃo protÃica, assim como, uma atividade quitinÃsica. As proteÃnas do lÃtex foram capazes de degradar azocaseÃna (substrato inespecÃfico) e BANA (substrato especÃfico para proteases cisteÃnicas). As enzimas proteolÃticas detectadas foram principalmente do tipo cisteÃnica, e em menor proporÃÃo, serÃnica. O pH e a temperatura Ãtimos para esta atividade foram 6,0 e 37 ÂC, respectivamente, onde valores de temperatura superiores anulam a atividade. Utilizando experimentos de dieta artificial pÃde-se observar que a fraÃÃo protÃica do lÃtex a 0,4 % foi capaz de diminuir em 50 % a sobrevivÃncia, e a 0,1 %, diminuir 50 % do ganho de massa das larvas de C. maculatus. Quando essas proteÃnas foram desnaturadas por aquecimento o desenvolvimento larval foi igual ao controle, sugerindo que a manutenÃÃo da estrutura protÃica à essencial para o efeito observado. As proteÃnas do lÃtex nÃo foram digeridas pelas proteases endÃgenas do trato digestÃrio das larvas, sugerindo que as mesmas ficariam livres para causar o efeito deletÃrio. Nenhum efeito no desenvolvimento das larvas de C. capitata foi observado quando as proteÃnas foram adicionadas à dieta, mesmo na concentraÃÃo de 4 %. O lÃtex Ãntegro, quando adsorvido em sementes de feijÃo, apresentou atividade inibitÃria do tipo repelente sobre a ovoposiÃÃo de ambos os bruquÃdeos testados, sendo mais evidente em Z. subfasciatus. A aÃÃo repelente observada foi dose e tempo dependente. O lÃtex nÃo foi capaz de afetar a viabilidade dos ovos e nem o desenvolvimento larval. As fraÃÃes PLPr e DL nÃo apresentaram atividade repelente, mostrando que nem proteÃnas nem molÃculas de baixa massa molecular estÃo envolvidas nessa aÃÃo. Os insetos, quando expostos diretamente ao lÃtex por longo perÃodo de tempo nÃo tiveram sua fecundidade nem ovoposiÃÃo afetados, sugerindo que o efeito observado nÃo altera a fisiologia do animal / Plumeria rubra L. is a laticÃfera plant belonging to the family Apocynaceae popularly known as Jasmim. For spicy and fragrant flowers make this tree is commonly seen ornate squares and gardens of residential urban centers. LaticÃfer plants are well known for producing a fluid endogenously generally milky in appearance - latex - that exudates from the plant when it undergoes some type of injury, either by mechanical damage or attack by predators. Latex is a material that has been the subject of biochemical and pharmacological studies show that it is a promising source of compounds with potential biotechnological application. In this study the latex of P. rubra was the subject of biochemical and biological research with emphasis on the search for proteins that could make any deleterious action against agricultural insect pests. Laboratory procedures that employ centrifugation and dialysis allowed the fractionation of latex into three distinct components: rubber (BL), proteins (PLPr) and low molecular weight molecules (DL). The PLPr fraction was subject to biochemical and enzymatic characterization and was used in bioassays with the bean weevil-of-rope, Callosobruchus maculatus and the fruit fly, Ceratitis capitata. The full latex and its fractions were used in testing the repellency of oviposition of C. maculatus and Zabrotes subfasciatus. The BL fraction is the major component of latex, 70 %, while PLPr and DL fractions are about 15 % each one. The content of soluble protein in PLPr fraction was 0.33 mg / mL. Espectrometric and electrophoretic analysis revealed the presence of proteins with molecular weights ranging from 12 to 117 kDa, with a maximum of protein with 26 kDa and pI <6.0. The characterization showed that the enzyme antioxidativas enzymes superoxide dismutase and peroxidase were detected in the protein fraction, as well as activity chitinases. Proteins of latex were able to degrade azocasein (nonspecific substrate) and BANA (specific substrate for cysteine proteases). The proteolytic enzymes were detected mainly of type cysteine and to a lesser extent, serine proteases. The pH and temperature optimum for this activity was 6.0 and 37 ÂC respectively, where higher values of temperature cancel the activity. Through experiments with artificial diet can be observed that the protein fraction of latex in 0.4 % was able to reduce by 50 % the survival and, in 0.1 %, reduce the by 50 % the weight gain of larvae of C. maculatus. When these proteins were denatured by heating the larval development was similar to the control, suggesting that the maintenance of protein structure is essential for the observed effect. Proteins of latex were not digested by endogenous proteases of the digestive tract of larvae, suggesting that they would be free to cause deleterious effects. No effect on the development of the larvae of C. capitata was observed when the proteins were added to the diet, even at a concentration of 4 %. Whole latex when adsorbed in bean seeds, showed repellent activity on oviposition of both bruchid, being more evident in Z. subfasciatus. The repellent activity was observed time and dose dependent. The latex was unable to affect the viability of eggs or larval development. The PLPr and DL fractions showed no repellent activity, showing that neither protein nor molecules with low molecular weight are involved in this action. The insects, when exposed directly to the latex for a long period of time had not affected their fecundity or oviposition.

Os revestimentos cerâmicos aderidos têm grandes vantagens estéticas e funcionais e seu emprego no mercado nacional vem sendo crescente, sobretudo com o uso de placas de porcelanato. Essas vantagens somente se concretizam com uma adequada durabilidade e vida útil, o que não vem ocorrendo com esses revestimentos aplicados em bases sujeitas a deformações e ou movimentações, como o caso de fachadas. Como camada de ligação entre o substrato e a placa cerâmica, as argamassas colantes apresentam papel fundamental para o revestimento cerâmico, tais como: suportar deformações e ou movimentações diferenciais, apresentar resistência mecânica duradoura e ter capacidade de aderir com segurança em qualquer substrato e placa cerâmica. O objetivo desse trabalho foi de estudar o comportamento de argamassas colantes com a aditivação de látex acrílico. Foi realizado um estudo experimental comparativo entre argamassas colantes monocomponentes e argamassas colantes aditivadas com látex acrílico. Para verificar o comportamento que essa aditivação proporciona, foram realizados ensaios de resistência de aderência, flexibilidade, resistência à compressão, resistência à tração na flexão com determinação de módulo de deformação e tempo em aberto com placas de porcelanato. Os resultados mostraram de uma forma geral que a aditivação de argamassas colantes proporcionam aumento significativo na flexibilidade. Ocorre melhora na resistência de aderência, resistência à compressão e resistência à tração na flexão e também na capacidade de absorver deformações com o aumento do teor de polímero/argamassa. A aderência em placas de baixa porosidade como o porcelanato é melhorada e o tempo em aberto de laboratório também é estendido para as argamassas modificadas com látex. / The directed adhere ceramic tiles has aesthetic and functional advantages, and its use in the national market is increasing specially with the use along with porcelain tile. These advantages can only be seen though, if the system has adequate durability and service live, which doesn\'t happen once it is applied on irreversible or cyclic movement basis as building façades. As the clingy layer between the ceramic tile and the substrate, the tile adhesives have fundamental importance for the directed adhered ceramic tile, working on deformation and movements support capability, long-term durability mechanic resistance and safety and reliability to adhere on all type of substrates and ceramic tile. The purpose of this work was to study the behavior of dry set mortar modified with acrylic latex. An experimental study has been done, comparing dry set mortar to acrylic latex Portland cement mortar. To verify the behavior that the latex provides, the following tests were realized: tensile bond adhesion, deformability, compressive strength and tensile strength with deformation modulus and open time with porcelain tile. The results showed in general, that the latex improved the flexibility of dry set mortar and the improvement of the tensile adhesion, compressive and tensile strength and deformability capacity by increasing the polymer/mortar content. The adhesion and open time in porcelain tile has been improved with latex Portland cement mortar.

Orientador: Fernando Galembeck / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-25T09:34:27Z (GMT). No. of bitstreams: 1 Silva_LucimaraLopes_D.pdf: 8828120 bytes, checksum: 3631493bce3c7f33cbc0007290af3e16 (MD5) Previous issue date: 2013 / Resumo: Neste trabalho, examinou-se o comportamento de dispersões aquosas de látex e seus nanocompósitos com argila, quando submetidos aos processos de moldagem por liofilização (freeze-casting) e eletrofiação (electrospinning). Os sólidos resultantes foram caracterizados principalmente por microscopia eletrônica de varredura (MEV). Através do freeze-casting do látex poli(estireno-co-acrilato de butila-co-ácido acrílico (P(S-BA-AA)) foi obtido um monolito de baixa densidade com variadas morfologias de poros (colunares, alongados e lamelares) e predominância de poros com morfologia do tipo espinha de peixe, semelhantes a "shish-kebabs" encontrados em polímeros semicristalinos. A moldagem por liofilização de espumas líquidas de látex com e sem argila originou espumas sólidas que apresentaram hierarquia de poros, com poros menores orientados sobre cavidades maiores, derivadas de bolhas de ar. As diferentes morfologias obtidas são modeladas pelo gelo, cujo hábito cristalino experimenta diversas transições morfológicas durante o processo de congelamento, devido às instabilidades térmicas na interface sólido-líquido (S/L). A técnica de eletrofiação permitiu obter fibras de blendas poliméricas imiscíveis e fibras nanocompósitas a partir de uma dispersão aquosa de látex poli(estireno-acrilato de butila) (P(S-BA)) misturada com soluções aquosas de poli(óxido de etileno) (PEO) de diferentes massas molares e argila. As fibras poliméricas apresentaram morfologia coaxial, com o polímero hidrofílico alojado preferencialmente na região interna, quanto menor for sua massa molar. As técnicas de espectroscopia de absorção no infravermelho (FTIR) e calorimetria diferencial de varredura (DSC) mostraram que o PEO é removido das fibras após o tratamento destas com água. Medidas de decaimento do potencial eletrostático de superfícies de polietileno de baixa densidade (PEBD), submetidas a tratamento corona, mostraram que a deposição das nanofibras de látex e PEO aceleraram a dissipação da carga elétrica da superfície deste dielétrico. Ensaios de adsorção mostraram que os nanocompósitos obtidos por ambas as técnicas são interessantes adsorventes do corante azul de metileno (AM), com eficiência de remoção comparável à da dispersão aquosa de argila / Abstract: In this work, we examined the behavior of latex aqueous dispersions and their nanocomposites with clay, when subjected to two polymer processing techniques: freeze-casting and electrospinning. The resulting solids were examined mainly by using scanning electron microscopy (SEM). By freeze-casting poly(styrene-co-butyl acrylate-co-acrylic acid) (P(S-BA-AA)) latex aqueous dispersion, a low density monolith was obtained with pores of varying morphologies (columnar, elongated and lamellar) and predominance of fishbone morphology resembling "shish-kebabs" found in semi-crystalline polymers. The freeze-casting of liquid latex foams with and without clay originated solid foams which contain small pores distributed along larger cavities derived from air bubbles. The different morphologies obtained was template by the frozen liquid precursor, which experiences several morphological transitions during the freezing process, due to thermal instabilities in the solid-liquid (S/L) interface. The electrospinning process afforded to obtain polymeric and composite nanofibers using poly (styrene-butyl acrylate) (P-S-BA) aqueous latex blended with poly(ethylene oxide) (PEO) solutions with different molecular weights and clay. Fibers show coaxial morphology, in which hydrophilic polymer and clay are in the inner of the fibers and latex is localized in the shell, as the molar mass of PEO decreases. Infrared (IR) and differential scanning calorimetry (DSC) techniques have shown that PEO is removed from fibers after water treatment. Measurements of the electrostatic potential decay on low-density polyethylene (LDPE) surfaces, charged with corona, showed faster electrostatic potential dissipation when polymeric nanofibers are deposited on LDPE. Sorbent tests of methylene blue (MB) dye revealed that nanocomposites prepared by both techniques show interesting dye sorbent properties, presenting same efficiency as the aqueous clay dispersion / Doutorado / Físico-Química / Doutora em Ciências

Les formulations des peintures à l’eau sont basées sur l’utilisation de suspensions colloïdales de particules de polymère dans l’eau (latex) et d’additifs dont principalement des pigments et des charges. La formation d’un film mince à matrice polymère par séchage d’un système colloïdal aqueux donne lieu à des phénomènes interdépendants d’une extrême complexité. Dans le cadre d’applications spécifiques, tels que le marquage routier, le séchage d’un latex formulé nécessite une minimisation des temps de séchage sans apport excessif d’énergie. Néanmoins, une fois sec, le film doit être aussi peu poreux que possible et avoir la meilleur tenue mécanique possible. L’objectif principal de cette thèse était d’identifier les paramètres clés pouvant jouer sur la vitesse de séchage d’une peinture aqueuse et de comprendre comment ces paramètres influencent les propriétés rhéologiques, les mécanismes de séchage du latex formulé et les propriétés mécaniques des films de polymères secs. Ceci dans le but d’apporter une meilleure compréhension au séchage de latex formulés ainsi qu’une aide à la formulation.Après identification des paramètres clés, des latex ont été synthétisés et formulés avec des additifs judicieusement choisis. L'influence des paramètres clés : nature du polymère, taille et distribution en taille des particules, ajout d'un agent de coalescence, d'un co-solvant, d'un agent dispersant et épaississant, de pigments et d’un agent de réticulation, a été étudiée au niveau du séchage des formulations et au niveau des propriétés mécaniques des films secs. Les études sur le séchage ont porté sur le séchage global, les mécanismes de déformation des particules et les mécanismes de séchage horizontal et vertical présent dans les latex. La vitesse de convection horizontale des particules a été mesurée par diffusion multiple de la lumière. Des comparaisons avec des modèles théoriques ont été effectuées. Les propriétés des films secs ont été comparées par analyse dynamique mécanique et par tribologie. / Aqueous paints are made of colloidal suspensions of polymer in water (latex) and additives (mainly pigments and fillers). Latex film formation consists of complex and interdependent phenomena. In case of specific applications, such as road marking, formulated latex must dry fast without excessive supply of energy. However, once dry, the film must be as less porous as possible, with good mechanical properties. The aim of this thesis was to identify the drying key parameters and to understand their influence on the rheology, the drying mechanisms of formulated latex and the mechanical properties of the dried films. The final goal was to have a better understanding of formulated latex drying in order to improve the formulations. After identification of the drying key parameters, latexes have been synthetized and formulated with specific additives. The influence of the following drying key parameters: nature of polymer, size and size distribution of particles, addition of coalescing aid, co-solvent, dispersing and thickening agent, pigments and cross linker, was studied regarding the formulation drying and the dried films mechanical properties. The drying studies focused on the global drying rate of the formulations, the particles deformation mechanisms and the horizontal and vertical drying mechanisms observed in latexes. The particles horizontal convection rate has been measured with multiple light scattering. Comparisons have been made with theoretical models. Dried films mechanical properties have been compared with dynamic mechanical analysis and tribology.

Les dispersions de nanocomposite à base aqueuse sont produites pour des applications diverses telles que les adhésifs, les revêtements et plus récemment les encres. Ce projet consiste à réaliser des encres conductrices nanocomposites comprenant des particules de polymère (latex) à basse température de transition vitreuse, Tg, pour la formation de films à température ambiante, et des plaquettes de graphène, en raison de leurs excellentes propriétés conductrices. Les charges conductrices, appelées multi-feuillets de graphène, sont réalisées par broyage en voie aqueuse de graphite (1-10 µm) stabilisées par différents tensio-actifs et/ou stabilisants. Cette méthode sans solvant et à bas coût permet de produire des suspensions de multi-feuillets (1-10 feuillets) de graphène. Les particules de polymères utilisées sont synthétisées par polymérisation en émulsion de monomères acrylates. Dans un second temps, des mélanges physiques de suspensions de graphène et de latex acrylates ont permis d’obtenir des encres nanocomposites. L’ajout de graphène permet l’obtention d’un seuil de percolation à bas taux de charge et une nette amélioration des propriétés électriques et du renfort. Le diamètre des billes de latex a une influence importante sur ces propriétés et a également été étudié. Afin d’augmenter la stabilité des suspensions et les interactions graphène/latex, des nanocomposites structurés ont été synthétisés par polymérisation in situ en émulsion, miniemulsion ou dispersion en présence de graphène. Les excellentes propriétés électriques associées à leur flexibilité font de ces matériaux des candidats adaptés pour la réalisation d’encres conductrices pour impression sur textile. / Printed electronics, particularly on flexible and textile substrates, raised a strong interest during the past decades. This project presents a procedure that provides a complete and consistent candidate for conductive inks based on a graphene/polymer nanocomposite material. It consists in the synthesis of conductive inks nanocomposites comprising polymer particles (latex) with low glass transition temperature, Tg, and graphene platelets, for the conductive properties. The conductive particles, named Nanosize Multilayered Graphene (NMG), are prepared by wet grinding delamination of micro-graphite suspensions stabilized by various surfactants and/or polymeric stabilizers. This solvent-free procedure allows the formation of NMG suspensions with low thickness (1-10 sheets). Polymer particles are synthetized by surfactant-free emulsion polymerization with acrylates monomers.Physical blending of latex particles and NMG platelets are performed to obtain conductive nanocomposites inks. Adding NMG induce a low percolation threshold and a sharp increase of the electrical and mechanical properties of the nanocomposites. Moreover, the polymer particles diameters have an impact on these properties.To increase the formation of a well-defined cellular microstructure, the nanocomposites are also synthetized by in situ polymerization in presence of NMG platelets, using emulsion, miniemulsion or dispersion polymerization. The excellent electrical properties of these nanocomposites associated to their flexibility make these materials suitable candidates for the production of conductive inks for textile printing applications.

Exposure to dust and latex allergens has been well established as a cause of health problems but there have been few studies that have examined the extent of problems in latex glove manufactures, especially in Thailand. Therefore, the overall aim of the study was to determine whether exposure to dust and latex allergens was associated with health problems in Thai latex glove manufacturing workers.The study was conducted in 3 latex glove factories in southern Thailand that employed 1,481 workers (931 Thai and 550 foreign workers). Full shift personal air sampling of workers in 10 different departments was carried out using the IOM Multidust™ sampling Head equipped with 25 mm 1.0 mm Polytetrafluoroethyene filters at a flow rate of 2 L/min. A commercial ELISA kit was employed to quantify levels of the Hev b 6.02 latex allergen in air sample extracts. Information on demographics and, occupational history, exposures and health related problems attributed to work was collected by questionnaires completed by Thai workers. Lung function testing using a spirometer was also conducted among Thai workers. Univariate linear mixed-model analysis was used to determine differences in the dust and specific latex allergen concentrations between factories, departments, shifts and days. Multivariate linear mixed model analysis was used to determine exposure determinants to estimate exposure concentrations of inhalable dust and specific latex allergen. Logistic regression analysis was used to determine association between exposure to inhalable dust and specific latex allergens.292 air samples were collected. The geometric mean (GM) and a range of inhalable dust was 0.88 (0.01 – 12.34) mg/m3. The highest dust levels were found in the Stripping 3.01, (0.73 – 12.34) mg/m3 and lowest in the Office 0.11, (0.06 – 0.92 mg/m3) departments. Hev b 6.02 levels were 9.35 (4.08 – 345.53) ng/m3 and the highest and lowest levels were also found in the Stripping [19.76, (4.72 – 192.90) ng/m3] and Office [5.60, (4.37 – 14.64) ng/m3] departments. Factory and Department were important determinants of both inhalable dust and Hev b 6.02levels. 660 (157 men, 503 women) out of 931 workers completed a self-reported questionnaire. The prevalence of health problems attributed to work was highest for skin problems (25.0%) followed by Rhinitis (23.9%), conjunctivitis (22.5%) and cough (16.2%). Cumulative exposure to dust was associated with conjunctivitis attributed to work (OR and 95%CI = 1.02, [1.00 - 1.03]) after adjusted for confounders. A negative association was found between rhinitis and exposure to average dust level (OR and 95%CI =0.69 [0.48 - 0.99]). No other associations were found between either exposure to dust and self-reported ill-health. There were also no association between exposure to Hev b 6.02 and ill-health although skin problems were associated with the highest Hev b 6.02 level (OR and 95% CI = 1.72 [1.02 - 2.91]). Lung function testing was conducted in 474 Thai workers; 41 had airway restriction, 3 airway obstruction and 1 with a combined problem. Cumulative exposure to dust was associated with airway restriction after adjustment for confounders (OR and 95% CI = 1.02 (1.00 - 1.04).

Catalysis is one of the Green Chemistry Principles given its importance for limiting environmental impacts and improving current processes, as well as for developing new sustainable processes and products. In order to provide more performant catalysts, this study provides a novel preparation method for controlling the distribution of metal nanoparticles (NPs) within hierarchically meso- and macroporous catalysts. It consists of the combination of latex synthesis, sonochemistry and sol-gel process. All these steps can be carried out in water, reducing environmental impact. The first step is the synthesis of latex, typically polystyrene. The second step is the sonochemical synthesis and deposition of noble metal NPs on the surface of the latex polymer. The third step is the synthesis of the support by sol-gel process using tetraethyl orthosilicate (TEOS) under controlled conditions to modulate the porosity of the final silica matrix. As a result, an original catalyst morphology is obtained with active sites preferentially located within the macropores, which are surrounded by a mesoporous matrix. Using this approach, a monodisperse polystyrene latex (~130 nm) was prepared by emulsion polymerisation and then decorated with Pt NPs (~2.3 nm) by sonochemical reduction. The mesoporous silica support was prepared by sol-gel synthesis in the presence of the decorated latex. After calcination, the organic template left behind macropores with the Pt NPs within the generated macropores. Mesopores (2-15 nm) connecting these macropores (110-400 nm) were tuned by varying the synthesis conditions. Typically, specific surface areas of 615 m2/g and total pore volumes of 0.74 cm3/g were obtained. In a first case of study, hierarchically porous Pt/SiO2 catalysts were evaluated in the selective hydrogenation of p-chloronitrobenzene (p-CNB) to produce p-chloroaniline. They exhibited activities up to 91.7 ± 2.9 molCNB/(min molPt) and selectivity values up to 100 ± 2% at 80% of conversion, in comparison with 47.7 ± 2.9 molCNB/(min molPt) and 91 ± 2%, respectively, obtained with a commercial catalyst under the same conditions. Moreover, in a second case of study, it was possible to prepare silica-supported Pd, Pd-Pt and Pd-CeO2 catalysts with hierarchical porosity (meso and macro). These materials were tested in the direct synthesis of hydrogen peroxide from hydrogen and oxygen. The best productivity of H2O2 was obtained with the bimetallic Pd-Pt catalyst with 32500 molH2O2/(h molmetal) in batch, and the best selectivity was obtained with Pd-CeO2/SiO2 catalyst (63 ± 2%) in semi-batch. In summary, this thesis proposes a new aqueous preparation method for hierarchically porous functional materials by the combination of latex synthesis, sonochemical reduction and sol-gel process. It has been demonstrated that this preparation technique provides a very powerful and versatile toolbox for catalyst tailoring and optimisation. Further perspectives to achieve improved morphologies and controlled active sites distribution are also proposed. / La catalyse est l'un des piliers pour le développement de procédés durables, car elle permet d'utiliser moins de ressources en accélérant les réactions chimiques. Afin de fournir des catalyseurs plus performants, cette étude propose une nouvelle méthode de préparation de catalyseurs pour contrôler la distribution de nanoparticules (NPs) métalliques au sein des catalyseurs hiérarchiquement poreux (méso et macro) en combinant la synthèse de latex, la réduction sonochimique et le procédé sol-gel. La première étape est la synthèse d'une empreinte porogène de billes de polystyrène (latex) obtenues par polymérisation en émulsion aqueuse. La deuxième étape est la synthèse et le dépôt de NPs de métaux nobles sur la surface des billes de polymère par voie sonochimique dans l’eau. La troisième étape est la synthèse du support catalytique par un procédé sol-gel en milieu aqueux en utilisant le latex décoré et l’orthosilicate de tétraéthyle (TEOS) dans des conditions contrôlées pour moduler la porosité finale de la matrice de silice (mésoporeuse). Toutes les étapes de cette approche sont effectuées dans l'eau, ce qui limite les impacts environnementaux de la préparation du catalyseur. L'élimination du porogène (latex) par calcination génère les macropores. Le matériau résultant possède alors une morphologie inédite pour un catalyseur, avec des macropores fonctionnalisés par des NPs métalliques, dans une matrice de silice mésoporeuse. Ainsi, il a été possible de synthétiser un latex monodisperse de polystyrène (~130 nm), lequel a été décoré avec des NPs de Pt (~2.3 nm) par réduction sonochimique. Le matériau final de silice a présenté des mésopores (2-15 nm) reliant les macropores (110-400 nm) contenant les NPs de Pt. Il a été possible d'obtenir des surfaces spécifiques et des volumes poreux totaux de 615 m2/g et 0,74 cm3/g, respectivement. Dans un premier cas d'étude, des catalyseurs de Pt/SiO2 à porosité hiérarchique ont été évalués dans l'hydrogénation sélective du p-chloronitrobenzene (p-CNB) pour produire la p-chloroaniline. Ils ont présenté des activités catalytiques allant jusqu'à 91,7 ± 2,9 molCNB/(min molPt) et des sélectivités jusqu'à 100 ± 2% à 80% de conversion, par rapport à 47,7 ± 2,9 molCNB/(min molPt) et 91 ± 2%, respectivement, obtenus dans les mêmes conditions avec un catalyseur commercial. Dans un deuxième cas d'étude, des catalyseurs à base de Pd, Pd-Pt et Pd-CeO2 supportés sur de la silice à porosité hiérarchique ont été préparés et testés dans la synthèse directe du peroxyde d'hydrogène. La meilleure productivité a été obtenue avec le catalyseur bimétallique Pd-Pt avec 32500 molH2O2/(h molmétal) en batch, et la meilleure sélectivité a été obtenue avec le catalyseur Pd-CeO2/SiO2 (63 ± 2%) en semi-continu. En résumé, cette thèse propose une nouvelle méthode de préparation dans l’eau de matériaux fonctionnels à porosité hiérarchique en combinant la synthèse de latex, la réduction sonochimique et le procédé sol-gel. Il a été démontré que cette technique de préparation fournit une boîte à outils très puissante et polyvalente pour la préparation et l'optimisation des catalyseurs. Des perspectives pour améliorer davantage les morphologies et la distribution contrôlée des sites actifs sont également proposées.

Orientador: José Antonio Malmonge / Resumo: A proporção aquosa liberada do leite durante a fabricação convencional de queijos é denominado soro de leite, este é considerado poluente devido a sua elevada carga orgânica, Demanda Bioquímica de Oxigênio (DBO) e Demanda Química de Oxigênio (DQO), como também pelo volume gerado. Para produzir 1 kg de queijo são gerados aproximadamente 9 kg de soro. Do total do soro produzido mundialmente estima-se que 50% sejam descartados em estações de tratamento de água ou reutilizados, como por exemplo, para alimentação de animais em fazendas. Também o fato do soro conter lactose, vitaminas e minerais, ele pode ser aproveitado principalmente para fabricação de alimentos. Procurando uma alternativa para este descarte produzido por pequenas e médias indústrias de laticínios e também com a necessidade de produzir materiais verdes e ecologicamente corretos, este trabalho avaliou a potencialidade do emprego do soro de leite como coagulante para látex de borracha natural (BN) e sua influência nas propriedades térmicas, mecânicas e tecnológicas da borracha crua da seringueira Hevea brasiliensis clone RRIM 600, cultivada na Fazenda Experimental da Faculdade de Engenharia de Ilha Solteira – SP. Foram avaliados os soros resultantes da produção de queijos muçarela, minas e cottage e como referência foi utilizado o coagulante ácido acético 3 mol L-1, o qual é utilizado pelas indústrias do setor. Para este estudo foi analisada a influência da temperatura e do tempo na acidez dos soros. Foram analisad... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aqueous released milk ratio during manufacturing of cheese is called whey, this is considered a pollutant because of its high organic load, Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD), as well as by the volume generated. To produce 1 kg of cheese are generated approximately 9 kg of serum. Of the total serum produced worldwide it is estimated that 50% are dropped in water treatment plants or reused, e.g. for feeding of animals on farms. The serum also contain lactose, vitamins and minerals, it can be used mainly for food manufacturing. Looking for an alternative to this disposal produced by small and medium-sized dairy industries and also with the need to produce green materials and eco-friendly, this study assessed the employment potentiality of the whey as coagulant for natural rubber latex (BN) and its influence on thermal, mechanical and technological properties of raw rubber of rubber trees Hevea brasiliensis clone RRIM 600, grown in the Experimental Farm of the Faculty of engineering of Ilha Solteira-SP. Were evaluated the resulting from the production of mozzarella cheese, mines and cottage and as reference was used coagulant acetic acid 3 mol L-1, which is used by the industries in the sector. This study examined the influence of temperature and time on acidity of serum. Were analyzed the properties: plasticity Wallace (P0), plasticity retention index [PRI (%)], Mooney Viscosity (VR) and thermogravimetric analysis (TG) of rubber coagulated usin... (Complete abstract click electronic access below) / Mestre

Package exams provides a framework for automatic generation of simple (statistical) exams. To employ the tools, users just need to supply a pool of exercises and a master file controlling the layout of the final PDF document. The exercises are specified in separate Sweave files (containing R code for data generation and LaTeX code for problem and solution description) and the master file is a LaTeX document with some additional control commands. This paper gives an overview on the main design aims and principles as well as strategies for adaptation and extension. Hands-on illustrations - based on example exercises and control files provided in the package - are presented to get new users started easily. (author´s abstract) / Series: Research Report Series / Department of Statistics and Mathematics