Les propriétés des latex, produits aux larges applications industrielles, dépendent d’un grand nombre de facteurs : le type de monomère, les stabilisants, les initiateurs ou encore la taille des particules. Les procédés comme les formulations utilisés sont nombreux. La répartition des particules – taille moyenne, écart moyen, polydispersité – est souvent gérée par une étape de coagulation qui suit la nucléation, menée dans un post réacteur. La maîtrise de la coagulation nécessite un contrôle parfait du procédé. Ces travaux de thèse, réalisés dans le cadre de l’ANR SCALE-UP, ont pour objectif d’étudier la coagulation de latex acryliques dans un procédé continu de taille millimétrique opérant en régime laminaire. Les mécanismes de coagulation sont mis en évidence dans des conditions physico-chimiques et hydrodynamiques contrôlées, et l’influence des différents paramètres sur la cinétique de coagulation est quantifiée. Une méthodologie à l’interface de plusieurs domaines (génie des procédés, physico-chimie, numérique) est adoptée. Dans un premier temps, les bases essentielles à la compréhension du phénomène de coagulation sont introduites. Cette étude permet de distinguer deux types de coagulation : péricinétique (liée au mouvement Brownien), et orthocinétique (reliée au cisaillement). Les modèles associés sont présentés, et l’influence du procédé discutée. La déstabilisation des latex par coagulation Brownienne est ensuite examinée. Après avoir introduit les principales techniques analytiques existantes et caractérisé les latex étudiés, une étude physico-chimique est menée. Un modèle permettant d’estimer le temps de coagulation en fonction des conditions de pH, force ionique et concentration du milieu est proposé, basé sur des mesures de mobilité électrophorétiques. La troisième partie consiste en l’étude hydrodynamique par CFD de deux réacteurs millimétriques : un tube enroulé et un réacteur intensifié (Dean-Hex), comparés à un tube droit. Le régime visé est le régime laminaire. La coagulation orthocinétique dépendant des taux de cisaillement dans le réacteur, l’objectif est d’observer l’écoulement ainsi que les distributions de ces taux dans le réacteur, afin d’anticiper l’influence du changement de géométrie sur la coagulation. Des informations locales sur l’écoulement sont obtenues par suivi lagrangien de particules. La répartition des taux de cisaillement comme les temps passés dans les zones aux plus forts taux sont très différents selon le réacteur, laissant présager des résultats différents en termes de mécanismes de coagulation et de taille finale des agrégats. Le quatrième chapitre présente les résultats expérimentaux obtenus en milliréacteur. Un pilote a été développé, permettant la mise en écoulement des fluides par pressurisation de réservoirs. La coagulation de latex de trois tailles initiale différente y est menée. Les échantillons prélevés le long du réacteur sont analysés par diffraction laser (Mastersizer 2000). Outre les distributions de taille, des informations sur la dimension fractale des agrégats sont extraites. Dans le cas de réacteurs tubulaires enroulés, des résultats en fonction de la concentration, du pH et du débit sont obtenus, permettant de déterminer l’influence de ces paramètres sur la cinétique. Des informations sur l’équilibre agrégation-rupture sont également disponibles à partir des expériences réalisées sur un des latex. Le régime d’écoulement laminaire, impliquant un mode de collision balistique, permet d’obtenir des agrégats de forme pratiquement sphérique. Une discussion concernant les conditions de travail en milliréacteur est menée, afin de cerner l’applicabilité de ce procédé. Dans une dernière partie, une méthode d’estimation de noyaux cinétiques, par Quadrature des Moments est présentée et appliquée à des résultats obtenus en réacteur de Taylor-Couette. De par le contrôle de l’hydrodynamique qu’il propose, un tel réacteur est parfaitement adapté à cette application. / Due to their large applicability, latexes are widely used in industries. Their properties depend on many parameters including the monomer, stabilizers and initiators used, and also the particle size. The particle size distribution of these suspensions is often regulated by a coagulation step, occurring after nucleation in a reactor. Coagulation control thus means perfect process control. This thesis, led in the framework of the project ANR SCALE-UP, aims at studying acrylic latex coagulation in millimetric-scale reactors in laminar flow. Coagulation mechanisms are highlighted in controlled physico-chemical and hydrodynamic conditions, and the influence of the various parameters on coagulation kinetics is quantified. A scientific methodology based on chemical engineering, physical-chemistry and fluid mechanics is employed. The first part of the thesis aims at presenting the theoretical basis of this work, where by the differences between perikinetic coagulation (driven by Brownian motion) and orthokinetic coagulation (related to shear) are distinguished. Models related to coagulation and rupture of aggregates are presented. As the reactor geometry is expected to have a significant impact on coagulation due to its sensitivity to shear, the influence of the geometry is also discussed. The second part of the work focuses on the stability of latex, which is related to Brownian coagulation. The main analysis techniques related to the size determination of aggregates are firstly discussed and a complete characterization of the latex used is presented. A physical-chemical study is then performed, resulting in the proposition of a model that allows the calculation of a coagulation time as a function of the properties of the latex suspension, namely pH, concentration and ionic strength. The third part presents a CFD study of two millimetric-scale reactors – a coiled tube and a meandering channel (Dean-Hex) reactor – and compares them with a straight tubular reactor. This work aims at studying the flow properties and shear rates produced inside these reactors in order to better understand their influence on the coagulation process. At equal flow rates, the Dean-Hex reactor proposes a narrower shear rate distribution compared with the tubular geometries, however very high shear rates are also generated and these are likely to modify the particle size distribution by breaking the aggregates. The fourth part of the thesis details the experimental results of the latex coagulation process in the coiled tube. A pilot-scale set-up was designed and constructed allowing the reactant feeds to be regulated and product sampling at eight points such that coagulation could be monitored with residence time. Samples were analyzed using dynamic light scattering (Mastersizer 2000), which enable the fractal dimension of aggregates to be obtained. The results of aggregate growth as a function of pH, flowrate and latex concentration are presented and provide information on the aggregation kinetics. A more concentrated latex is used to gain insight on aggregation-rupture equilibrium. Considering the fractal dimension of the larger aggregates, the equilibrium size was found to linearly decrease with the average shear rate. Also, laminar flow was found to result in more spherical aggregates than what is obtained in a batch reactor due to the ballistic collision mode involved. A discussion on the effects of experimental conditions (concentration, pH and flow rates) and the limitations of millimetric-scale equipment for latex aggregation is initiated. The final part of the work aims at introducing a population balance model for the aggregation process using the Quadrature Method of Moments (QMOM) and results obtained in a Taylor-Couette reactor. This device offers good control of hydrodynamics and it istherefore well suited to the determination of aggregation and rupture kernels.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesta dissertação foi estudado um processo de polimerização em emulsão de acrilonitrila, butadieno e ácido carboxílico, em escala piloto, para a produção de látex nitrílico carboxilado com alto teor de sólidos diretamente no processo reacional, sem precisar passar por etapas pós-reação de concentração. Foi estudado o efeito da temperatura, do tipo e quantidade de emulsificante, do tipo e quantidade de iniciador, do tipo de agitador e da velocidade de agitação e das etapas de adição incremental para obtenção de látex com alto teor de sólidos e a sua influência no tamanho e distribuição das partículas. Os polímeros obtidos foram caracterizados por gravimetria, usando forno de microondas para obtenção do teor de sólidos, espalhamento de luz, para determinação de tamanho e distribuição das partículas, e por espectroscopia na região do infravermelho para determinação da composição monomérica. Foi obtido polímero com até 57% de sólidos totais. O tamanho médio de partícula variou de 130 nm a 230 nm. / In this dissertation an emulsion polymerization process of acrylonitrile, butadiene and carboxylic acid was studied, in pilot scale, for the production of carboxylated nitrile latex with high solids content directly from the reaction process, without the need of post-reaction steps of concentration. It was studied the effect of temperature, type and amount of emulsifier, type and amount of initiator, type of stirring system, stirring speed and the steps of incremental additions for the production of high solid latex and its influence in the average particle size and distribution. The obtained copolymers were characterized by gravimetry using a microwave oven to determine total solids content, by light scattering in order to determine the average particle size and its distribution and by infrared spectroscopy to determine monomer composition. A latex up to 57% of total solids was obtained. The average particle size ranged from 130 nm to 230 nm.

Os elásticos ortodônticos intermaxilares sintéticos vem sendo cada vez mais utilizados, sendo principalmente indicados para pacientes que apresentam hiper-sensibilidade ao látex. Afim de avaliar e comparar o comportamento de elásticos de látex e sintéticos quanto a perda de força ao longo do tempo, este estudo foi realizado tanto in vitro quanto in vivo. Para o estudo in vitro foram avaliados 15 elásticos de cada material, para cada tempo: 0, 1, 3, 12 e 24 horas. No estudo in vivo, pacientes foram avaliados (N=15), utilizando elásticos de ambos os materiais (látex e sintético), nos mesmos tempos do estudo in vitro. Os elásticos foram transferidos para a máquina de ensaios mecânicos (EMIC DL-500 MF). Os valores da força gerada foram registrados após a distensão dos elásticos a uma distância de 25mm. Foi aplicado o teste t pareado para a amostra clínica e independente para a amostra laboratorial. Foi utilizada a análise de variância (ANOVA) para verificar a variação das forças geradas entre os tempos determinados e o teste post-hoc para identificar entre quais tempos houve diferença significativa. Quanto às forças iniciais geradas (zero hora), os valores para os elásticos sintéticos foram bastante semelhantes entre os estudos laboratorial e clínico e ligeiramente superiores aos dos elásticos de látex. Nos tempos subsequentes, as forças geradas pelos elásticos de látex apresentaram valores superiores. Em relação à degradação do material, ao final de 24 horas, maior percentual foi observado para os elásticos sintéticos, tanto in vitro quanto in vivo. A maior queda nos valores das forças liberadas pelos elásticos de ambos os materiais e nos estudos clínico e laboratorial, ocorreu entre os tempos de 0 e 1 hora, seguida de uma queda gradativa e progressiva até o tempo de 24 horas. Os elásticos de látex apresentaram um comportamento mais estável no período estudado em relação aos sintéticos, em ambos os estudos. / Synthetic intermaxillary orthodontic elastics are being increasingly used and they are primarily indicated for patients with hypersensitivity to latex. In order to evaluate and compare the behavior of latex and synthetic elastics, as the loss of strength, over time, this study was conducted both in vitro and in vivo. For the in vitro study, 15 of each elastic material was evaluated for each time: 0, 1, 3, 12 and 24 hours. For the in vivo study, patients were evaluated (N = 15) using both elastic materials (latex and synthetic) at the same times settled in vitro study. The rubber bands were transferred to the testing machine (EMIC DL-500 MF). The values of the force were recorded after stretching the elastic to a length of 25mm. Matched to the clinical and independent for laboratory sample t test was applied. Analysis of variance (ANOVA) was used to check the variation of the forces generated between those determined times and the post-hoc test to identify between which times were marked difference . As regards the initial forces (time zero), the values for synthetic elastic were quite similar between laboratory and clinical studies and slightly higher than the latex elastic. In subsequent times, the forces generated by the latex elastic showed higher values. Regarding the material degradation at the end of 24 hours, the highest percentage was observed for synthetic elastic, both in vitro and in vivo. The largest drop in the values of forces unleashed by the elastic of both materials and the clinical and laboratory studies occurred between times of 0 and 1 hour, followed by a gradual decreases until the time of 24 hours. The latex elastic had a more stable behavior during the period studied compared with synthetic, in both studies.

Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-30Bitstream added on 2014-06-13T18:41:44Z : No. of bitstreams: 1 pagnano_lo_dr_jabo.pdf: 626602 bytes, checksum: 91e708f2a8ad849761e7177151a3d66e (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / O objetivo deste trabalho foi avaliar o potencial de cicatrização de uma fração de proteína extraída do látex da seringueira em diferentes concentrações (0,01% e 0,001%) associada a diferentes biomateriais (Fibracol plusÒ e ácido hialurônico a 1%). Utilizaram-se 36 coelhos albinos da raça Nova Zelândia Branco submetidos à realização de 4 feridas em cada orelha. Dividiu-se o experimento em etapas de acordo com a análise do período pós-operatório (3º, 7º, 14º e 21º dias), sendo utilizados 9 animais para cada etapa. Na primeira etapa (3º dia de pósoperatório), os animais foram numerados aleatoriamente de 1 a 9, sendo que em 3 animais, nas orelhas esquerdas, as feridas foram tratadas com solução salina (T1) e nas orelhas direitas, as feridas foram tratadas com membrana de Fibracol plus® + FrHb1 a 0,01% (T2). Em outros 3 animais, realizaram-se os mesmos procedimentos, diferenciando os tratamentos, onde nas feridas das orelhas esquerdas o tratamento foi com Fibracol plus® (T3) e nas feridas das orelhas direitas Fibracol plus® + FrHb1 a 0,001% (T4). Nos 3 animais restantes, seguiram-se os mesmos procedimentos, inserindo nas feridas das orelhas esquerdas ácido hialurônico a 1% + FrHb1 a 0,01% (T5) e nas feridas das orelhas direitas ácido hialurônico a 1% + FrHb1 a 0,001% (T6). Os animais foram sacrificados no 3º dia de pós-operatório e as feridas foram analisadas macroscopicamente e em seguida separadas para a análise histológica. Estes procedimentos foram repetidos para as etapas de 7, 14 e 21 dias de pós-operatório. Os segmentos de tecidos com as feridas foram fixados em solução de Bouin por 24 horas, e processados rotineiramente, para inclusão em paraplast e posterior avaliação histológica e morfométrica. A morfometria foi realizada por meio do sistema... / The aim of this study was to evaluate the potential for healing of a fraction of protein extracted from the latex of rubber trees in different concentrations (0.01% and 0.001%) associated with various biomaterials (Fibracol plus®1 and hyaluronic acid to 1%). There were used 36 New Zealand White rabbits underwent achievement of 4 wounds on each ear. The experiment was divided into stages according to the analysis of the postoperative period (3, 7, 14 and 21 days), and 9 animals used for each step. In the first stage (day 3 post-surgery), animals were randomly numbered from 1 to 9, with 3 animals in the left ear, the wounds were treated with saline (T1) and the right ear, the wounds were treated with membrane of Fibracol plus® + FrHb1 to 0.01% (T2). In 3 other animals, the same procedures were held, differing treatments, where the wounds of the left ear they were treated with Fibracol plus® (T3) and the wounds of the right ears Fibracol Plus® + FrHb1 to 0.001% (T4). In the 3 remaining animals, there was followed by the same procedures, including the ears wounds hyaluronic acid at 1% + FrHb1 to 0.01% (T5) and right ears wounds of hyaluronic acid 1% + FrHb1 a 0.001% (T6). The animals were sacrificed at 3 days postoperatively and the wounds were examined macroscopically and then separated for histological analysis. These procedures were repeated on the steps of 7, 14 and 21 days postoperatively. The segments of the injured tissues were fixed in Bouin solution for 24 hours and routinely processed for inclusion in paraplastic and subsequent histologic and morphometric evaluation. The morphometry was performed using the image analyzing system (Image Pro-PLUS2) and the evaluation of healing was done by enumeration of leukocytes and fibroblasts. The data were subjected to statistical analysis (ANOVA and Tukey test at 5%)... (Complete abstract click electronic access below)

Thesis (MTech (Biomedical Technology))--Cape Technikon, 2000. / Professionals in a healthcare setting use latex gloves on a daily basis, primarily to prevent transmission of microbial and viral organisms to and from patients and specimens. Repeated exposure to latex proteins (through direct skin contact or mucous membrane absorption) leads to the formation of circulating latex-specific antibodies and increases the risk of sensitisation. Among all known risk groups, healthcare workers have the highest risk to develop latex hypersensitivity. Early detection of antibodies or predisposing factors (e.g. atopy or impaired skin barrier function), could assist in the identification and management of risk groups and limit possible sensitisation. An experimental group with high occupational latex exposure is compared to a control group with low or no occupational latex exposure at Tygerberg Hospital, Cape Town. A questionnaire was completed by all subjects to obtain a thorough history of past and present latex exposure and to identify other risk factors. A complete physical examination was done to evaluate clinical signs and symptoms of risk factors and latex hypersensitivity. Atopy was evaluated by means of the United Kingdom's Diagnostic Criteria for Atopy, personal and lor family history of atopy, haematogram and total serum IgE analyses. Latex-specific IgE antibodies were measured immunometrically. Skin prick tests were performed on subjects with negative in vitro results, but with predefined clinical symptoms suggestive of latex hypersensitivity. An

Orientadora: Silvana Martinez Baraldi Artoni / Banca: Isabel Cristina Boleli / Banca: Antônio Carlos Alessi / Banca: Joaquim Coutinho Netto / Banca: João José Lachat / Resumo: O objetivo deste trabalho foi avaliar o potencial de cicatrização de uma fração de proteína extraída do látex da seringueira em diferentes concentrações (0,01% e 0,001%) associada a diferentes biomateriais (Fibracol plusÒ e ácido hialurônico a 1%). Utilizaram-se 36 coelhos albinos da raça Nova Zelândia Branco submetidos à realização de 4 feridas em cada orelha. Dividiu-se o experimento em etapas de acordo com a análise do período pós-operatório (3º, 7º, 14º e 21º dias), sendo utilizados 9 animais para cada etapa. Na primeira etapa (3º dia de pósoperatório), os animais foram numerados aleatoriamente de 1 a 9, sendo que em 3 animais, nas orelhas esquerdas, as feridas foram tratadas com solução salina (T1) e nas orelhas direitas, as feridas foram tratadas com membrana de Fibracol plus® + FrHb1 a 0,01% (T2). Em outros 3 animais, realizaram-se os mesmos procedimentos, diferenciando os tratamentos, onde nas feridas das orelhas esquerdas o tratamento foi com Fibracol plus® (T3) e nas feridas das orelhas direitas Fibracol plus® + FrHb1 a 0,001% (T4). Nos 3 animais restantes, seguiram-se os mesmos procedimentos, inserindo nas feridas das orelhas esquerdas ácido hialurônico a 1% + FrHb1 a 0,01% (T5) e nas feridas das orelhas direitas ácido hialurônico a 1% + FrHb1 a 0,001% (T6). Os animais foram sacrificados no 3º dia de pós-operatório e as feridas foram analisadas macroscopicamente e em seguida separadas para a análise histológica. Estes procedimentos foram repetidos para as etapas de 7, 14 e 21 dias de pós-operatório. Os segmentos de tecidos com as feridas foram fixados em solução de Bouin por 24 horas, e processados rotineiramente, para inclusão em paraplast e posterior avaliação histológica e morfométrica. A morfometria foi realizada por meio do sistema... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this study was to evaluate the potential for healing of a fraction of protein extracted from the latex of rubber trees in different concentrations (0.01% and 0.001%) associated with various biomaterials (Fibracol plus®1 and hyaluronic acid to 1%). There were used 36 New Zealand White rabbits underwent achievement of 4 wounds on each ear. The experiment was divided into stages according to the analysis of the postoperative period (3, 7, 14 and 21 days), and 9 animals used for each step. In the first stage (day 3 post-surgery), animals were randomly numbered from 1 to 9, with 3 animals in the left ear, the wounds were treated with saline (T1) and the right ear, the wounds were treated with membrane of Fibracol plus® + FrHb1 to 0.01% (T2). In 3 other animals, the same procedures were held, differing treatments, where the wounds of the left ear they were treated with Fibracol plus® (T3) and the wounds of the right ears Fibracol Plus® + FrHb1 to 0.001% (T4). In the 3 remaining animals, there was followed by the same procedures, including the ears wounds hyaluronic acid at 1% + FrHb1 to 0.01% (T5) and right ears wounds of hyaluronic acid 1% + FrHb1 a 0.001% (T6). The animals were sacrificed at 3 days postoperatively and the wounds were examined macroscopically and then separated for histological analysis. These procedures were repeated on the steps of 7, 14 and 21 days postoperatively. The segments of the injured tissues were fixed in Bouin solution for 24 hours and routinely processed for inclusion in paraplastic and subsequent histologic and morphometric evaluation. The morphometry was performed using the image analyzing system (Image Pro-PLUS2) and the evaluation of healing was done by enumeration of leukocytes and fibroblasts. The data were subjected to statistical analysis (ANOVA and Tukey test at 5%)... (Complete abstract click electronic access below) / Doutor

Os elásticos ortodônticos intermaxilares sintéticos vem sendo cada vez mais utilizados, sendo principalmente indicados para pacientes que apresentam hiper-sensibilidade ao látex. Afim de avaliar e comparar o comportamento de elásticos de látex e sintéticos quanto a perda de força ao longo do tempo, este estudo foi realizado tanto in vitro quanto in vivo. Para o estudo in vitro foram avaliados 15 elásticos de cada material, para cada tempo: 0, 1, 3, 12 e 24 horas. No estudo in vivo, pacientes foram avaliados (N=15), utilizando elásticos de ambos os materiais (látex e sintético), nos mesmos tempos do estudo in vitro. Os elásticos foram transferidos para a máquina de ensaios mecânicos (EMIC DL-500 MF). Os valores da força gerada foram registrados após a distensão dos elásticos a uma distância de 25mm. Foi aplicado o teste t pareado para a amostra clínica e independente para a amostra laboratorial. Foi utilizada a análise de variância (ANOVA) para verificar a variação das forças geradas entre os tempos determinados e o teste post-hoc para identificar entre quais tempos houve diferença significativa. Quanto às forças iniciais geradas (zero hora), os valores para os elásticos sintéticos foram bastante semelhantes entre os estudos laboratorial e clínico e ligeiramente superiores aos dos elásticos de látex. Nos tempos subsequentes, as forças geradas pelos elásticos de látex apresentaram valores superiores. Em relação à degradação do material, ao final de 24 horas, maior percentual foi observado para os elásticos sintéticos, tanto in vitro quanto in vivo. A maior queda nos valores das forças liberadas pelos elásticos de ambos os materiais e nos estudos clínico e laboratorial, ocorreu entre os tempos de 0 e 1 hora, seguida de uma queda gradativa e progressiva até o tempo de 24 horas. Os elásticos de látex apresentaram um comportamento mais estável no período estudado em relação aos sintéticos, em ambos os estudos. / Synthetic intermaxillary orthodontic elastics are being increasingly used and they are primarily indicated for patients with hypersensitivity to latex. In order to evaluate and compare the behavior of latex and synthetic elastics, as the loss of strength, over time, this study was conducted both in vitro and in vivo. For the in vitro study, 15 of each elastic material was evaluated for each time: 0, 1, 3, 12 and 24 hours. For the in vivo study, patients were evaluated (N = 15) using both elastic materials (latex and synthetic) at the same times settled in vitro study. The rubber bands were transferred to the testing machine (EMIC DL-500 MF). The values of the force were recorded after stretching the elastic to a length of 25mm. Matched to the clinical and independent for laboratory sample t test was applied. Analysis of variance (ANOVA) was used to check the variation of the forces generated between those determined times and the post-hoc test to identify between which times were marked difference . As regards the initial forces (time zero), the values for synthetic elastic were quite similar between laboratory and clinical studies and slightly higher than the latex elastic. In subsequent times, the forces generated by the latex elastic showed higher values. Regarding the material degradation at the end of 24 hours, the highest percentage was observed for synthetic elastic, both in vitro and in vivo. The largest drop in the values of forces unleashed by the elastic of both materials and the clinical and laboratory studies occurred between times of 0 and 1 hour, followed by a gradual decreases until the time of 24 hours. The latex elastic had a more stable behavior during the period studied compared with synthetic, in both studies.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Nesta dissertação foi estudado um processo de polimerização em emulsão de acrilonitrila, butadieno e ácido carboxílico, em escala piloto, para a produção de látex nitrílico carboxilado com alto teor de sólidos diretamente no processo reacional, sem precisar passar por etapas pós-reação de concentração. Foi estudado o efeito da temperatura, do tipo e quantidade de emulsificante, do tipo e quantidade de iniciador, do tipo de agitador e da velocidade de agitação e das etapas de adição incremental para obtenção de látex com alto teor de sólidos e a sua influência no tamanho e distribuição das partículas. Os polímeros obtidos foram caracterizados por gravimetria, usando forno de microondas para obtenção do teor de sólidos, espalhamento de luz, para determinação de tamanho e distribuição das partículas, e por espectroscopia na região do infravermelho para determinação da composição monomérica. Foi obtido polímero com até 57% de sólidos totais. O tamanho médio de partícula variou de 130 nm a 230 nm. / In this dissertation an emulsion polymerization process of acrylonitrile, butadiene and carboxylic acid was studied, in pilot scale, for the production of carboxylated nitrile latex with high solids content directly from the reaction process, without the need of post-reaction steps of concentration. It was studied the effect of temperature, type and amount of emulsifier, type and amount of initiator, type of stirring system, stirring speed and the steps of incremental additions for the production of high solid latex and its influence in the average particle size and distribution. The obtained copolymers were characterized by gravimetry using a microwave oven to determine total solids content, by light scattering in order to determine the average particle size and its distribution and by infrared spectroscopy to determine monomer composition. A latex up to 57% of total solids was obtained. The average particle size ranged from 130 nm to 230 nm.

Orientador: Fernando Galembeck / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-04T22:53:27Z (GMT). No. of bitstreams: 1 Valadares_LeonardoFonseca_M.pdf: 2704224 bytes, checksum: 7117cbcbd90ead01e5b79c4d6efb650a (MD5) Previous issue date: 2005 / Mestrado / Físico-Química / Mestre em Química

Orientador: Fernando Galembeck / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T10:30:17Z (GMT). No. of bitstreams: 1 Rippel_MarciaMaria_D.pdf: 28336240 bytes, checksum: d54ace138d40b3edcabb2029aeef4d5e (MD5) Previous issue date: 2005 / Doutorado / Físico-Química / Doutor em Ciências