Orientador: Maria Regina Wolf Maciel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-23T17:27:22Z (GMT). No. of bitstreams: 1 BermudezJaimes_JohnHervin_M.pdf: 3572961 bytes, checksum: 92daf8d40cc8f811247948545b00f432 (MD5) Previous issue date: 2013 / Resumo: Na presente dissertação, descreve-se a síntese do ácido acrílico por método semi-sintético. Na primeira etapa, produz-se ácido láctico por fermentação de melaço de cana-de-açúcar, em biorreator BioFlo 415, usando as bactérias Lactobacillus delbrueckii, Lactobacillus plantarum e Leuconostoc mesenteroides, com estudo prévio, em Shaker, da temperatura, concentração de sacarose e concentração de extrato de levedura usadas com cada bactéria. Na fermentação com Lactobacillus delbrueckii, obteve-se o ácido láctico de concentração de 50,21 g/L e produtividade final de 1,26 g/L.h. Com Leuconostoc mesenteroides se produz uma concentração máxima de ácido láctico de 14,57 g/L com produtividade final de 0,41 g/L.h; e usando Lactobacillus plantarum se obteve uma concentração de ácido láctico de 50,59 g/L com produtividade final de 1.09 g/L.h. Na segunda etapa, sintetizou-se ácido acrílico por desidratação catalítica do ácido láctico comercial e do ácido láctico obtido da fermentação com Lactobacillus plantarum em reator tubular, a 300 °C e fluxo contínuo de CO2. Para isso, foram preparados, caraterizados e testados catalisadores suportados em zeólita básica do tipo NaY (KBr/NaY, KI/NaY e Ca3(Po4)2/NaY). Como resultado, quando o ácido láctico comercial foi usado, a maior seletividade obtida foi de 25,66 % com uso de KBr/NaY; já com o ácido láctico obtido por fermentação, a maior seletividade obtida foi de 16,65 % com uso de KI/NaY. Durante o presente projeto, os produtos tanto das fermentações como das desidratações foram caraterizados por cromatografia líquida de alta eficiência (HPLC) / Abstract: The present work deals whit the synthesis of acrylic acid by semi-synthetic method. In the first step, lactic acid was produced by fermentation of sugarcane molasses, in bioreactor BioFlo 415, using the bacteria Lactobacillus delbrueckii, Lactobacillus plantarum and Leuconostoc mesenteroides with a previous study, in Shaker, of the temperature, sucrose and yeast extract concentration used to each bacterium. In the fermentation with Lactobacillus delbrueckii, it was produced lactic acid with concentration of 50.21 g/L and final productivity of 1.26 g/L.h; with the Leuconostoc mesenteroides, it was produced lactic acid with concentration of 14.57 g/L and final productivity of 0.41 g/L.h; and using Lactobacillus plantarum, it was obtained a concentration of lactic acid of 50.59 g/L with final productivity of 1.09 g/L.h. In the second stage, acrylic acid was synthesized by catalytic dehydration of commercial and fermented lactic acid in a tubular reactor at 300 °C and continuous flow of CO2. For this, the catalyst support on NaY Zeolite basic (KBr/NaY, KI/NaY and Ca3(PO4)2/NaY) were prepared, characterized and tested. As results, when the commercial lactic acid was used, the largest selectivity was of 25.66% with use of KBr/NaY; whereas with lactic acid obtained by fermentation, the largest selectivity was of 16.65% using KI/NaY. In this design, all products were characterized by high performance liquid chromatography (HPLC) / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

Orientadores: Rafael Leonardo Xediek Consani, Janaína de Cássia Orlandi Sardi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-23T21:37:58Z (GMT). No. of bitstreams: 1 Silva_ManoelaCapladeVasconcellosdosSantosda_D.pdf: 1387678 bytes, checksum: 17ea18ac10fef54c8580345c3bba0454 (MD5) Previous issue date: 2013 / Resumo: Este trabalho avaliou o efeito do número de ciclos de desinfecção por energia de micro-ondas na dureza Knoop, rugosidade e brilho de resinas termopolimerizadas para prótese total. Foram confeccionados 20 corpos-de-prova de cada material medindo 20 mm de diâmetro por 2 mm de altura, os quais foram distribuídos em 6 grupos de acordo com as resinas: QC-20, Onda Cryl, Clássico, Vipi Cril, Vipi Wave e Vipi Caracterizada. Todos os corpos-de-prova foram submetidos aos ensaios de rugosidade, dureza e brilho antes (controle, dia 0) e em cada ciclo de desinfecção (7, 14, 21 e 28 dias). Os corpos-de-prova foram polimerizados de acordo com as recomendações dos fabricantes, desincluídos e o acabamento realizado com pedra abrasiva para resina, lixas de carbeto de silício e pastas para polimento. A desinfecção por micro-ondas foi realizada a 650 W por 3 minutos, uma vez por dia durante 28 dias. Entre as desinfecções, as amostras permaneceram imersas em água e armazenadas em estufa a 37°C. Nos ensaios de rugosidade e dureza Knoop foram realizadas três mensurações na superfície de cada corpo-de-prova, sendo registrada a média das leituras. Os valores de brilho foram mensurados com medidor de brilho e para cada corpo-de-prova foram realizadas quatro mensurações, uma em cada quadrante, com feixe de luz incidindo em 60 graus. Os valores obtidos foram submetidos à ANOVA dois fatores para medidas repetidas, e teste de Tukey (5%). Os resultados mostraram que a resina Clássico apresentou o maior e a Vipi Wave o menor valor de rugosidade. Quando se avaliou a dureza, a resina Onda Cryl apresentou os maiores valores nos ciclos de 14 e 21 dias e não houve diferença estatística nos valores de dureza Knoop entre as demais resinas. A resina QC-20 apresentou os maiores valores de brilho, sendo maiores no controle (dia 0) e nos ciclos de 7 e 14 dias, os quais foram diferentes estatisticamente dos ciclos de 21 e 28 dias. Concluiu-se que houve influência da desinfecção por micro-ondas na rugosidade e dureza de todas as resinas, independente do número de ciclos. Com exceção da Clássico, as demais resinas mostraram valores de brilho com diferença estatisticamente significativa entre controle e ciclos de desinfecção / Abstract: This study evaluated the effect of repeated disinfection by microwave irradiation on hardness, surface roughness and gloss of denture base acrylic resins. Twenty samples were prepared for each material measuring 20 mm in diameter and 2 mm in height, which were divided into six groups according to the resins: QC-20, Wave Cryl, Classico, Vipi Cril, Vipi Wave and Vipi Characterized. All samples were tested for roughness, hardness and gloss analysis before and after disinfection cycles. Samples were polymerized according to the manufacturers' recommendations, deflasked and finished with abrasive stones, silicon carbide abrasives and polishing slurry. Disinfection by microwave irradiation was made at 650 W for 3 minutes, one time by day during 28 days. Between disinfection cycles the samples were stored in an incubator at 37°C. Three roughness measurements were made on the polished surface and the average was recorded as the roughness value (Ra, mm) for each sample. Hardness was recorded with three Knoop penetrations with a load of 50 kgf for 10 seconds. Three readings of each sample were used to obtain arithmetic mean for each analysis. The gloss values were measured with glossmeter. Four measurements were performed in each sample, one in each quadrant focusing the light beam at 60 degrees. The readings were recorded as the value of unit gloss (Gloss Unit - GU) and the data were recorded in the software. The values obtained were subjected to two-way ANOVA for repeated measures and Tukey's test (5%). The results showed that Classico had the highest value and Vipi Wave the lowest for surface roughness. Onda Cryl showed the highest values for hardness at 14- and 21-day cycles and there was no statistical difference among other resins. For gloss, QC-20 resin showed the highest values being higher at control and 7- and 14-day cycles, statistically different from 21- and 28-day cycles. It was concluded that there was influence of microwave irradiation in the roughness and hardness for all resins, regardless the number of cycles. Whit exception of Classico, there was statistically significant difference in gloss for all acrylic resins / Doutorado / Protese Dental / Mestre em Clínica Odontológica

Orientadores: Saide Sarckis Domitti, Simonides Consani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-25T16:08:45Z (GMT). No. of bitstreams: 1 Padovan_SilviaHelenaMarques_M.pdf: 4194064 bytes, checksum: 105fde7936dddc9bb8c66110ab9ade0a (MD5) Previous issue date: 1999 / Resumo: O objetivo deste estudo foi avaliar as alterações de adaptação em bases de prótese total, confeccionadas com resina acrílica de rápida polimerização (QC-20) em função das técnicas de polimerização. Foram confeccionados 15 modelos em gesso pedra a partir da moldagem de um modelo mestre metálico. Sobre estes modelos foram confeccionadas bases de prótese com espessura uniforme de 1,5 mm, divididas aleatoriamente em 3 grupos de 5 amostras e incluídos em muflas específicas, segundo os Grupos: 1- ciclo convencional (polimerização em banho de água aquecida a 74°C por 9 horas); 2- ciclo rápido (polimerização em água fervente em 20 minutos); e, 3- por energia de microondas (polimerização em forno de microondas a 500W por 3 minutos). Após o resfriamento das muflas em temperatura ambiente, as bases-de-prótese foram removidas, limpas, acabadas e fixadas em seus respectivos modelos com adesivo instantâneo Super Bonder (Loctite). O conjunto, base de prótese-modelo foi seccionado em três secções láterolaterais e as superfícies seccionadas lixadas numa politriz. Em cada secção foram demarcados 7 pontos referenciais para a leitura da desadaptação, verificada num microscópio comparador e os resultados obtidos foram submetidos à análise estatística e ao teste de Tukey em nível de significância de 5%. A resina acrílica QC-20 quando polimerizada pelos ciclos de 9 horas e de 20 minutos apresentou estatisticamente melhor adaptação quando comparadas ao ciclo por microondas. A maior média de desadaptação ocorreu na linha média da região posterior, quando a base foi polimerizada pelo ciclo de microondas / Abstract: The aim of this work was to evaluate changes in adaptation of denture bases made with rapid curing acrylic resin (QC-20) considering the polymerization techniques. Fifteen plaster of Paris models were made from the modeling of a metalic master mode!. Sample bases, with regular width of 1.5 mm, were made over these models, ramdomly divided ln three groups containing five replicas and incIude in specific flasks, according to the Groups: 1- convencional cycle (polymerization in water at 74°C for 9 hours); 2- rapid cycle (polymerization in boiling water for 20 minutes); and, 3-through microwave energy (polymerization in microwave oven at 500W for 3 minutes). After the flasks have been cooled at room temperature, the resin bases were removed, trimmed, and fixed on their models with instant bonder Super Bonder (Loctite). The denture base and the model set was sectioned in three latero-lateral sections and the cut surfaces polished in a politriz. ln each section, seven mark points were made to make possible the analysis of the non-adaptation. The adaptation was verified in a comparing microscope and the results were submitted to a statistical analysis and to the Tukey' s test, with a significance leveI of 5%. The acrylic resin QC-20, when polymerized through the cicles of 9 hours and 20 minutes, showed statistically better adaptation when compared to the microwave cycle. The greatest average oí non-adaptation occured in the midline oí the posterior area, when the base was polimerized through the microwave cycle / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Composites, in which the matrix and the reinforcing fillers are respectively, poly(acrylic acid) (PAA) with two different molecular weights, and chitin whiskers (CHW) were successfully prepared using an evaporation method. The weight fraction of CHW was varied from 0.03 to 0.73. Mechanical and thermal properties and crystallinity of the composites were characterised using tensile testing, differential scanning calorimetry, thermogravimetric analysis and X-ray diffraction. The tensile strength of the composite increased up to 11 wt % CHW after which it decreased. XRD characterisation showed a decrease in crystalline index, crystalline size, chitin crystalline peak and intensity as the content of PAA and its molecular weight increased. Raman spectroscopy was used for the first time to monitor the deformation of chitin film and CHW reinforced PAA composites. The Raman band located at 1622 cm^(-1) was monitored for deformation. On application of tensile deformation the Raman band initially located at 1622 cm^(-1) shifted toward a lower wavenumber. Raman band shift rates of -1.85 cm^(-1)/% for chitin film and -0.59 and -0.25 cm^(-1)/% for 73 and 23 wt % CHW content, respectively, were measured. The modulus of a single chitin whisker and composites were found to be 115, 37 and 16 GPa respectively, for a two dimensional (2D) in-plane distribution of CHW. CHW within a PAA matrix did not show any preferential alignment in a polarised Raman. The Raman intensity ratio〖 I〗_1698 /I_1622 showed that the strongest interaction of the carboxylic group in the composites occured at 3 wt % CHW content. The interaction gradually reduced as the CHW content increased. 〖 CaCO〗_3 crystals were grown in CHW, PAA and CHW/PAA composites by a solution and evaporation casting method. In the absence of PAA and CHW, rhombohedral calcites were observed while rod-like aragonite polymorphs were seen when only PAA was used as a template. In the presence of only CHW, a morphological mixture of ellipsoidal and disc shape with traces of rhombohedral aggregate calcite were the features. In the presence of both PAA and CHW, the rhombohedral shape showed roughness with irregular faces while the vaterite polymorph continued to agglomerate with the observation of porosity at higher CHW content. The vaterite particles gradually decreased as the CHW content was decreased. At lower CHW content aragonite polymorph growth was favoured to the detriment of calcite. The results showed that the vaterite polymorph can be grown even at higher filler loading. The effect of 〖 CaCO〗_3 growth on the mechanical properties of CHW reinforced PAA indicated that better mechanical properties can be achieved at a CHW content of 3 wt % when compared with neat PAA and when 〖 CaCO〗_3 was not incorporated into the CHW/25PAA composites.

In industry the effective mixing and de-agglomeration of two solid particles is vital in applications that require the intimate contact of homogeneously mixed reagents. One such application is in the preparation of pyrotechnic delay elements with reproducible burn speeds. The concept of surfactant assisted particle micro-mixing is proposed. This theory is based in the use of two amphiphilic polymeric surfactants to form two separate stable dispersions of the two solid particles to be mixed, but with the subsequent requirement that the dispersants are able to interact with each other. The formation of the individual dispersions allows for the deagglomeration of the particles and thus their preparation for homogeneous mixing, which is facilitated by the interacting surfactants. Low molecular mass block copolymers of styrene and acrylic acid and poly( ethylene oxide)-poly(propylene oxide) (PEO-PPO) surfactants are the proposed dispersants which will allow for the surfactant interaction by means of hydrogen bonding between the poly(acrylic acid) block and the PEO. The poly(styrene-co-acrylic acid) block copolymer will be synthesised via Atom Transfer Radical Polymerisation (ATRP) and subsequently used in the dispersion experiments. The synthesis of the polystyrene macroinitiators to initiate the block copolymerisation of the t-butyl acrylate was carried out satisfactorily, with good molecular masses and molecular mass distributions. In addition, lH-NMR analysis carried out on the polystyrene macroinitiators confirmed their synthesis. The use of the polystyrene macroinitiators was successful in synthesising poly(styrene-co-t-butyl acrylate) block copolymers with slightly higher polydispersities in comparison to the macroinitiatiators themselves, but acceptable. Hydrolysis of the poly(styrene-co-t-butyl acrylate) block copolymer to poly(styrene-co-acrylic acid) was successful in the presence of trifluoroacetic acid as catalyst. Attempts to hydrolyse in basic conditions (NaOH) and alternatively in acidic conditions (HCI) were not successful. Use of the poly(styrene-co-acrylic acid) amphiphilic block copolymer to emulsion polymerise styrene requires the ionised form of the polymer and was therefore not favourable to observe surfactant-surfactant hydrogen bonding. In addition, attempts to synthesise a wax emulsion stabilised by a PEO containing surfactant proved to be unsuccessful. Subsequently, the micro-mixing experiments were carried out by using a poly(acrylic acid) stabilised melamine dispersion and a commercially available PEO containing surfactant stabilised wax emulsion. The interaction between the melamine and the poly(acrylic acid) allows for the formation of a stable melamine dispersion at above 7% poly(acrylic acid) : melamine ratio (mass basis). Analysis by SEM shows that without the poly( acrylic acid) dispersant no wax particles are found to occur on the melamine particle surface. However, in an attempt to determine whether the amount of wax interaction increases with poly(acrylic acid) content, it was found that in the absence of poly(acrylic acid) dispersant, the most amount of wax precipitated out with the melamine. This is possibly attributable to the preferential occlusion of the wax particles between the melamine particles rather than surface attachment. Introduction of the poly(acrylic acid), however, shows via SEM analysis that the hydrogen bond interaction between the acrylic acid group and the ethylene oxide group does occur, since the attachment of the wax particles on the melamine particle surface is observed. Although results show that the surfactant-surfactant interaction allows for the micro¬mixing of particles, some refinement is required with respect to the systems that this phenomenon can be applied to. In addition, factors such as particle type, particle size and surfactant type will influence the micro-mixing interaction. It is therefore recommended that these factors be investigated in order to completely identify the micro-mixing phenomenon. / Dissertation (M Eng (Chemical Engineering))--University of Pretoria, 2006. / Chemical Engineering / unrestricted

Orientador: Telma Teixeira Franco / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-07T15:01:29Z (GMT). No. of bitstreams: 1 Tsukamoto_Junko_D.pdf: 1866337 bytes, checksum: 5cac22304ad7fddc116a61d4e57a941f (MD5) Previous issue date: 2006 / Resumo: Reações enzimáticas em meio orgânico têm despertado grande interesse industrial devido às vantagens de obtenção de produtos puros pela maior especificidade das enzimas, pela redução de gastos energéticos e pela possibilidade de desenvolvimento de condições menos agressivas de processo. O uso de enzimas em síntese é uma alternativa viável à síntese orgânica e pode ser compreendida como processo relacionado ao novo conceito de ¿biotecnologia industrial¿ (white biotechnology), devido às preocupações ambientais e da sustentabilidade dos processos químicos. Processos biotecnológicos permitem a exploração racional de materiais renováveis (açúcares) para obtenção de produtos industriais, diminuindo a degradação ambiental. Uma rota enzimática é aqui proposta para obtenção de acrilatos de açúcares, monômero para confecção de polímeros biodegradáveis. O uso de enzimas em síntese orgânica oferece vantagens devido a especificidades na formação de produto, onde os custos de separação, purificação e tratamento de resíduos são minimizados. As lipases são responsáveis por 20% das biotransformações realizadas atualmente. Ésteres derivados de carboidratos e de ácidos graxos vêm sendo produzidos para a indústria alimentícia e farmacêutica, entretanto, mas não se encontram ainda ésteres tais como acrilatos de carboidratos no mercado. Esse projeto visou um estudo da produção de acrilatos de carboidratos pela reação direta via enzimática pela lipase comercial CalB. A esterificação de três monossacarídeos (D-glicose, D-frutose e D-xilose) e dois dissacarídeos (sacarose e maltose) com ácido acrílico pela CalB no solvente terc-butanol foi estudada. O efeito dos três seguintes parâmetros foi avaliado: temperatura, razão molar entre os reagentes (açúcar: ácido acrílico) e quantidade de enzima sobre a conversão a ésteres foi avaliada. A conversão da reação foi acompanhada por cromatografia líquida (CLAE-IR) e por MALDI TOF MS / Abstract: Industrial interest in enzymatic reactions in organic media is due to the possibility of obtain pure compounds with the use of highly specific enzyme, the decrease in energy costs and the possibility of using mild process conditions. The development of new enzymatic processes for chemical synthesis as a viable alternative to the organic synthesis is related to the new concept of "industrial biotechnology" (white biotechnology), with higher concerns with the environment and the sustainability of chemical processes. Biotechnological processes that make a more rational use of renewed resources such as sugars to produce chemicals decrease, in most cases, the environmental impact. In this work an enzymatic route is proposed for the production of sugar acrylates, a biodegradable monomer. The use of enzymes in organic media has the advantage of high specificity to the desired product, lower separation and purification costs, and minimization of residue formation. Currently, lipases are responsible for 20% of all biotransformations. Esters derived from fatty acid and carbohydrates are produced for the food and pharmaceutical industries. However, acrylate esters of carbohydrate are still not found in the market. This aim of this work was to study the production of acrylates of carbohydrates by the direct enzymatic reaction of sugars with acrylic acid on the commercial lipase CalB. The esterification of three monosaccharide (D-glucose, D-fructose and xylose) and two disaccharides (sucrose and maltose) with acrylic acid on CalB in tert-butanol was studied. The effects of temperature, molar ratio of the reactants (sugar to acrylic acid) and amount of enzyme on the conversion to esters were studied. The esterification reaction was monitored by HPLC and MALDI TOF MS / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

Orientadores: Renata Cunha Matheus Rodrigues Garcia, Altair Antoninha Del Bel Cury / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-07T23:27:29Z (GMT). No. of bitstreams: 1 Faot_Fernanda_D.pdf: 1972781 bytes, checksum: b3ce58297c07d4abe90d5b2bf79729e7 (MD5) Previous issue date: 2006 / Resumo: Fraturas por impacto e flexão ainda são os principais problemas relatados tanto pelos portadores de próteses removíveis como pelos cirurgiões dentistas. Na tentativa de solucionar esse problema, alterações na composição química das resinas acrílicas como a inclusão de co-polímeros, adição de agente de ligação cruzada e a incorporação de partículas de borracha na forma de butadieno estireno têm sido propostas. Entretanto, poucos estudos avaliaram a incorporação destes aditivos modificadores de impacto no processo de fratura, deformação e microestrutura de resinas acrílicas. Além disso, devido à fragilidade dos materiais poliméricos a presença de trincas e fraturas em base de próteses removíveis ainda é alta e reparos são procedimentos comuns tanto por métodos diretos ou indiretos. Entretanto, as propriedades mecânicas de resinas acrílicas reparadas ainda não estão claramente descritas. Assim, os objetivos do presente trabalho foram: I) avaliar a resistência ao impacto e a flexão, bem como tensão de ruptura, módulo Young e deslocamento de escoamento de resinas acrílicas contendo modificadores de impacto e analisar sua microestrutura; II) determinar a resistência ao impacto e flexão de resinas acrílicas para base de prótese previamente fraturadas e reparadas com resinas fotopolimerizável, autopolimerizável e termopolimerizável. Como resultado, observou-se que a resina contendo borracha considerada de alto impacto, demonstrou alta capacidade de dissipação de energia, absorção de tensão e baixo percentual de deformação; entretanto exibiu processo de fratura frágil. Com relação às resinas utilizadas para reparo, concluiu-se que reparos realizados com a mesma resina usada para confecção dos corpos-de-prova, apresentaram melhores resultados quanto à resistência mecânica / Abstract: Fractures by impact and flexural action are the main problems described by denture users and dentists. Attempting to solve this problem, modifications on the chemical composition of the acrylic resins as co-polymer inclusion, cross linking agents addition and rubber particles incorporation in the form of butadiene styrene have been described as effective and worthwhile means to improve the impact strength and fracture propagation. However, literature lacks information regarding the incorporation of these modifying impact additives in the fracture process, plastic deformation and microstructure of acrylic resins. Furthermore, due to the brittleness of the polymeric materials, the presence of cracks and fractures in the removable prosthesis denture bases still remains high. Thus, frequent repairs are somewhat common procedures in the clinical practice, being by direct or indirect methods. Therefore, the effect of the repairs materials on the mechanical properties of acrylic resins is not clearly described yet. Front of these considerations, the purposes of the present study were: I) evaluate the impact and flexural strength, as well as, stress at yield, Young modulus and displacement at yield of acrylic resins containing impact modifiers and analyze their microstructure; II) determine the impact and flexural strength of denture base acrylic resins previously fractured and repaired with visible-light, auto and heat-polymerized acrylic resins. As results, it could be observed that the acrylic resin containing rubber particles, considered as the high impact, showed high capacity of energy dissipation and stress absorption before the fracture, lower percentage of deformation, however it exhibited brittle fracture process. Regarding to acrylic resins used as repair materials, it was concluded that repairs performed with the same resin used to fabricate the specimens showed the best results for mechanical resistance / Doutorado / Protese Dental / Doutor em Clínica Odontológica

Orientador: Celia Marisa Rizzatti Barbosa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-31T18:51:13Z (GMT). No. of bitstreams: 1 Nadin_PauloSergio_D.pdf: 3982871 bytes, checksum: 60b40819eee30b6dd20d8ff8604c5f8a (MD5) Previous issue date: 2001 / Resumo: O objetivo deste trabalho foi avaliar a adaptação e a alteração na inclinação dental dos primeiros molares de próteses totais superiores em função do método de polimerização, e da sorção de água apresentada pela resina, frente a alterações de pressão e temperatura de armazenagem das amostras. Foram confeccionadas 60 próteses divididas em 4 grupos: (G I) polimerizadas em água 73 :I: 2 °C / 9 horas e armazenadas em água à 37 :I: 2 °C por 30 dias; (G 11) polimerizadas em água 73 :I: 2 °C / 9 horas e armazenadas em água sob temperatura de 60 :I: 2°C, pressão de 40 Lib/PoF por 1 hora; (G lU) polimerizadas por energia de microondas 500W / 3 minutos e armazenadas em água de 37 :I: 2 °C por 30 dias; (G IV) polimerizadas por energia de microondas 500 W / 3 minutos e armazenadas em água sob temperatura de 60 :I: 2°C, pressão de 40 Lib/PoF por 1 hora. Foi feita a análise da inclinação dental nos períodos de enceramento (TO), de polimerização (TI), polimento (T2) e sorção de água (T3). Para o teste de adaptação, a base foi analisada na região de primeiros molares, em sete pontos pré-estabelecidos. Estes foram feitos nos períodos de polimento (TO) e após a de sorção de água (TI). Os dados obtidos foram submetidos à análise de variância e teste de Tukey ao nível de 5 % de significância. Estes demonstraram que as alterações mais significativas da inclinação dental ocorreram em todos os grupos após o processamento das amostras (TI), sendo de 2,3 °, 0,85 °, 2,54 °, e 3,47° para os grupos I, 11, 111 e IV respectivamente (p<0.05). Conclui-se que: 1) As maiores alterações na inclinação dos dentes ocorreram entre os períodos de enceramento e polimerização, em média 2,29 graus. 2) As alterações na inclinação dental durante o polimento e após o fenômeno de sorção de água não foram estatisticamente significantes. 3) Não houve diferença significativa na inclinação dos dentes entre os métodos de polimerização por energia de microondas e por banho de água convencional. 4) Os métodos de tratamento utilizados para sorção de água influenciaram igualmente as alterações ocorridas. 5) A melhor adaptação ocorreu na região palatina para o grupo 111 sendo em (TO) 0,142 mm e (TI) 0,134 mm. 6) Na região de tlanco observou-se a menor variação na adaptação entre TI e T2 (0,005 mm). 7) De modo geral após a sorção de água houve melhora na adaptação / Abstract: The aim of this work was to evaluate the adaptation and change in dental inclination of the first molars in upper complete dentures in function of the curing method and water sorption shown by the resin, before changes in pressure and temperature of storage of the samples. Sbcty dentures were constructed and divided into 4 groups: (G I) cured in 73° C water/ 9 hours and water sorption of37° C for 30 days; (G 11) cured in 73° C water/ 9 hours and water sorption under a temperature of 60° C, pressure of 40 Libs/inch2 per hour; (G 111) curing by microwave energy 500W/3 minutes and water sorption of 37° C for 30 days; (G IV) cured by microwave energy 500W/ 3 minutes and water sorption under a temperature of 60° C, pressure of 40Libs/inch2 per hour. An analysis was made on the dental inclination in waxing (TO), curing (TI); polishing (T2) and water sorption (T3) periods. For the adaptation test, the base was analyzed in the first molar region, in seven pre-established points. These were made in the polishing period (TO) and after water sorption (TI). The obtained data were submitted to variance analysis and Tukey's test at a 5% significance level. These demonstrated that the most significant changes of dental inclination had occurred in ali groups after the processing of the samples (TI), being of 2,3°, 0,85°, 2,54° and 3,47° for groups I, 11, 111 and IV, respectively (p<0.05). It is concluded that: 1) The biggest changes in dental inclination occurred between the waxing and curing periods, an average of 2,29 degrees. 2) The changes in dental inclination during the polishing and after the phenomenon of water sorption were statistically insignificant. 3) There was no significant difference in tooth inclination between the curing methods by microwave energy and conventional water bath. 4) The methods of treatment used for water sorption influenced equally the occurred changes. 5) The best adaptation occurred in the palatine region for group IH, being in (TO) 0,142 mm and (TI) 0,134 mm. 6) In the flange region, it was observed the least variation in adaptation between TI and T2 (0,005 mm). In a general sense, there was an improvement in adaptation after water sorption / Doutorado / Protese Dental / Doutor em Clínica Odontológica

Neste trabalho foi investigado o processo de relaxação em copolímeros metacrilicos funcionalizados com o grupo cromóforo 4-[N-etil-N-(2-hidroxietil)]amino-2\'-cloro-4\'nitro-azobenzeno (MMADRI3). Os copolímeros sintetizados foram caracterizados por espectrofotometria de visível e infravermelho, calorimetria diferencial de varredura, análise termogravimétrica e elipsometria. O triodo de corona foi utilizado para induzir a orientação dos cromóforos dipolares a temperaturas próximas da transição vítrea. Os valores do coeficiente eletroóptico linear r13 de filmes obtidos por derramento de solução podem alcançar 14 pm/V em amostras funcionalizadas com 43%de cromóforo.O efeito piezoelétricoé significativo para amostras contendo 4% de cromóforo sendo a sua origem atribuída à carga espacial. A relaxação orientacional dos cromóforos foi estudada medindo-se o decaimento do coeficiente eletroóptico e a relaxação dielétrica a diferentes temperaturas. O processo de relaxação foi interpretado utilizando a equação de Kohlraush-Williams-Watts (KWW) aplicada aos domínios do tempo e da freqüência. O tempo de relaxação característico &#964 e o parâmetro b da equação de KWW foram obtidos como função da temperatura desde a temperatura ambiente até acima da temperatura de transição vítrea. O parâmetro b à temperatura de transição vítrea aproxima-se de 0,6 valor que é atribuído a forças de curto alcance. As medidas dielétricas revelaram duas bandas de relaxação &#946 e &#945 respectivamente a baixas e a altas temperaturas. A relaxação a está relacionada com a transição vítrea e à desorientação dos cromóforos. A dependência de &#964 foi fundamentada nas equações de Arrhenius e de Vogel-Fulcher-Tarmnann-Hesse (VFTH), respectivamente a baixas e a altas temperaturas. Os parâmetros de VFTH encontram-se próximos dos considerados universais. O comportamento de &#964 em toda a gama de temperaturas, foi explicado pela equação de Adam-Gibbs, usando-se os parâmetros de VFTH. O resfriamento a taxas lentas após o processo de polarização aumenta substancialmente o tempo de relaxação e a sua energia de ativação. Os expoentes m e n do modelo de Dissado-Hill baseado na interação de multicorpos foram obtidos em função da temperatura. Os valores do parâmetro n ficam dentro do esperado pela teoria / The relaxation process of side-chain methacrylate copolymers functionalized with the nonlinear optical azo chromophore 4-[Nethyl-N-(2-hydroxyethyl)]-amino-2\'-chloro-4-nitroazobenzene (MMADR13) was investigated. The copolymers synthesized were characterized by visible and infrared spectrophotometry, differential scanning calorimetry, thermogravimetric analysis and ellipsometry. The corona triode was employed to induce the orientation of the dipolar chromophore at a temperature near the glass transition. The linear eletrooptic coefficient r13 of cast fllms can reach values as high as 14 pm/V in samples with 43% of chromophore contento The piezoeletric effect attributed to space charge was only significant in the lowest chromophore content samples (4%). Electrostriction was shown to affect to some extent the quadratic electrooptic measurements. The chromophore relaxation at different temperatures was investigated by both electrooptic decay and dielectric measurements. The relaxation process was interpreted using the Kohlraush-Williams-Watts (KWW) equation both in the time and frequency domains. From the KWW equation the characteristic relaxation time &#964 and the stretching parameter b were obtained from room temperature to temperatures above the glass transition. Near the glass transition b is ca 0.6 which is characteristic of short range interactions. Dielectric measurements revealed two relaxation bands, &#946 and &#945, at low and high temperatures, respectively. The &#945 relaxation was attributed to the glass transition and to the 10ss of chromophore orientational order. The temperature behavior of &#964 was interpreted by the Arrhenius and Vogel-Fulcher-Tammann-Hesse (VFTH) equations. at low and high temperatures. respectivelly. The VFTH parameters lie close to the so-called universal values. In addition the overall temperature dependence was explained by the Adam-Gibbs equation using the VFTH parameters. Using a small cooling rate after corona poling increases substantially the relaxation time and the activation energy .The power law exponents m and n. from Dissado-Hill manybody interactions model were obtained as a function of temperature. The n values are in the range of expected values for the many-body interactions model

Content: The purpose of this paper is to study the influence of acrylic resins on the properties of the hide when added in the pickling-tanning stage of a wet white process. Among retanning products, acrylic resins are very frequently used because they lend very good properties to the hide on account of their high affinity for chromium. When applied during chrome tanning, these resins provide the hides with high fullness, due to the strong interaction of the carboxylate groups with chromium. Extensive bibliography is available on the application of acrylic resins in wet blue, where it is observed that the properties they provide to the hides depend basically on the type of monomers and molecular weight. However, less information is found when these products are applied in wet white tanning. In this study, 9 resins with different molecular weights and different monomer compositions were selected. Resins were applied to pelt leathers of Spanish origin split at 3.5 mm. Hides were cut along the backbone. A standard process was applied to the left halves and the same process adding the resin was applied to the right halves. The resin was added after adjusting the salt of the bath and before adding the pickling acids. The COD was measured before and after adding formic and sulfuric acid, and the shrinkage temperature and the degree of whiteness of the tanned hide were assessed. Hides were retanned and fatliquored with a standard process, and degree of softness, thickness, color intensity and organoleptic properties (fluffiness, compactness and grain tightness) were assessed. Leather shrinkage under temperature was also assessed, and images of leather sections were obtained by scanning electron microscopy (SEM). While acrylic resins did not increase shrinkage temperature, they did fix and/or deposit themselves in the interfibrillary spaces of the hide; indeed, highly reduced COD values after acidification in the pickling stage were observed. This study shows that homopolymeric acrylic resins provided fuller and fluffier hides, while the rest of resins practically did not improve the physical and organoleptic properties of the hides. Take-Away: Homopolymeric acrylic resins provided full er and fluffier hides, while the rest of resins practically did not improve the physical and organoleptic properties of the hides Wet white tanning improvement