Orientador: Brenda Paula Figueiredo de Almeida Gomes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T12:50:39Z (GMT). No. of bitstreams: 1 Brum_CimaraBarrosoBraga_M.pdf: 2334153 bytes, checksum: 49e166f146a6c9e8ce963d4b8955dd40 (MD5) Previous issue date: 2013 / Resumo: Este estudo teve por objetivo avaliar ex vivo a capacidade de desinfecção de diferentes técnicas de instrumentação utilizando os sistemas ProTaper, ProTaper + Gates, EndoEze, Mtwo e limas manuais em canais contaminados com Enterococcus faecalis, utilizando hipoclorito de sódio 1%, clorexidina gel 2% e soro fisiológico associados a diferentes protocolos de irrigação. Para este fim, 150 molares superiores humanos extraídos, previamente acessados, tiveram as entradas dos canais palatino e mésio-vestibular seladas com resina composta, para que somente o canal disto-vestbular fosse utilizado. O mesmo foi instrumentado até uma lima K #20 para estabelecer o diâmetro da lima anatômica inicial. Após estes procedimentos, os dentes foram autoclavados e posteriormente contaminados por 21 dias com Enterococcus faecalis. Em seguida os dentes foram divididos aleatoriamente em 15 grupos de 10 espécimes cada, de acordo com a técnica de instrumentação e o protocolo de irrigação utilizado. Amostras microbianas do canal radicular foram coletadas e cultivadas antes (coleta inicial - C1) e após a instrumentação (coleta da luz do canal - C2 e coleta de raspas de dentina - C3), para a determinação das unidades formadoras de colônia (UFC). A análise estatística foi realizada através dos testes de Kruskal Wallis/ Dunn para as comparações intergrupo, e Friedman ou Wilcoxon para as comparações intragrupo considerando o nível de significância de 0,05. Verificou-se que na luz do canal radicular não houve diferença entre as técnicas de instrumentação empregadas, independente da substância química auxiliar utilizada. Quanto às substâncias testadas, tanto a clorexidina gel 2% quanto o hipoclorito 1% foram igualmente efetivos na redução de Enterococcus faecalis, enquanto que o soro fisiológico obteve resultados inferiores. Concluiu-se que as técnicas de instrumentação testadas, independente do sistema utilizado, foram eficazes em reduzir os níveis de Enterococcus faecalis na luz do canal radicular associadas ao hipoclorito de sódio 1% ou a clorexidina gel 2% / Abstract: The aim of this study was to evaluate ex vivo the disinfection ability of different instrumentation techniques using the ProTaper System, ProTaper + Gates, EndoEze System, Mtwo System and stainless still K- files, in root canals infected with Enterococcus faecalis using 1% sodium hypochlorite, 2% chlorhexidine gel and sterile saline associated with different irrigation protocols. For this purpose, 150 extracted upper human molar teeth were previously accessed and had the palatal and mesiobuccal canals sealed with composite and only the distobuccal canal was used. The DB canal was instrumented to a #20 K file to establish the diameter of the initial anatomical file. After these procedures, the teeth were autoclaved and subsequently infected during 21 days with Enterococcus faecalis. Then, the teeth were randomly divided into 15 groups of 10 specimens each, according to the instrumentation technique and irrigation protocol used. Root canal microbial samples were collected and cultured before (initial - C1) and after instrumentation (canal - C2 and dentine ships - C3) in order to count the colony forming units (CFU). Statistical analyses were performed using the Kruskal Wallis/ Dunn tests for intergroup comparisons, and Friedman or Wilcoxon for intragroup comparisons, considering the significance level of 0.05. It was found that there was no difference between the instrumentation techniques employed, independent of auxiliary chemical substance used. Regarding the substances tested, both 2% chlorhexidine gel and 1% sodium hypochlorite were equally effective in reducing Enterococcus faecalis, while the saline obtained inferior results. It was concluded that the tested instrumentation techniques, regardless of the system used, have been effective in reducing the levels of Enterococcus faecalis in the root canal associated with sodium hypochlorite 1% or 2% chlorhexidine gel / Mestrado / Endodontia / Mestra em Clínica Odontológica

Orientador: Regina Maria Puppin-Rontani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:12:27Z (GMT). No. of bitstreams: 1 Borges_AnaFlaviaSanches_M.pdf: 3516462 bytes, checksum: a51b845dc96d230cbc181dac6262187f (MD5) Previous issue date: 2005 / Resumo: As restaurações indiretas de compósito são uma das alternativas na clínica odontopediátrica, pois, proporcionam a redução da duração da sessão clínica, além da possibilidade da diminuição da contração de polimerização inerente ao pequeno volume do agente de fixação resinoso. Em casos de dentes tratados endodonticamente, o desempenho das restaurações ¿adesivas¿ não se encontra bem estabelecido, e estas são de extrema importância uma vez que a falha nas restaurações das coroas de dentes submetidos à terapia pulpar pode significar a perda do tratamento endodôntico. Assim, os objetivos desta dissertação fundamentada em dois artigos foram: (1) avaliar a adaptação marginal inicial de restaurações tipo onlay de compósito em dentes decíduos previamente submetidos ou não à irrigação com hipoclorito de sódio 1% (NaOCl 1%) e cimentados com dois sistemas resinosos para fixação (EnForce e Rely X), (2) avaliar os efeitos do tratamento com NaOCl 1% e dois agentes resinosos de fixação na recuperação da força compressiva de dentes decíduos restaurados com onlays de compósito e analisar os padrões de fratura produzidos quanto ao grau de severidade. No estudo 1, a amostra foi constituída de quarenta molares decíduos hígidos, restaurados com restaurações indiretas tipo onlay de compósito resinoso, divididos em grupos conforme os dois fatores de variação estabelecidos para o estudo: irrigação com (NaOCl 1%) e agentes de fixação resinosos (EnForce e Rely X). Para a análise da adaptação marginal foi aplicada uma solução corante nas margens da restauração, e, as áreas coradas foram consideradas como presença de fendas marginais. O software Image Tool 3.0 foi utilizado para a mensuração linear do comprimento das fendas. No estudo 2, trabalhou-se com a mesma amostra do estudo 1, com o acréscimo do grupo controle composto de dentes hígidos, totalizando cinqüenta dentes. Todos os espécimes foram submetidos ao teste mecânico de compressão, os tipos de fratura foram classificados macroscopicamente quanto aos graus de severidade e os sítios de fratura foram analisados em microscopia eletrônica de varredura a título de ilustração. No estudo 1, não houve diferença estatisticamente significativa quanto à quantidade de fendas encontrada entre os grupos (p>0.05), porém, o risco relativo de ausência de fenda revelou que alguns grupos apresentaram maior chance de ausência de fenda que outros, sendo que o grupo com maior risco relativo foi o grupo tratado com hipoclorito e fixado com EnForce (RR=1.56). No estudo 2, não houve diferença quanto aos valores de força compressiva entre os grupos estudados (p>0.05), consequentemente, os grupos experimentais apresentaram recuperação da resistência à compressão, alcançando valores que não diferiram daqueles do grupo controle. Quanto ao grau de severidade das fraturas, os grupos experimentais mostraram os tipos mais severos de fratura, enquanto o grupo controle apresentou os tipos menos severos. Assim, a técnica restauradora indireta de compósitos resinosos em dentes decíduos com preparos cavitários complexos e submetidos à simulação do procedimento de irrigação endodôntica, apresentou adequada adaptação marginal inicial e foi capaz de recuperar a resistência à carga compressiva em relação aos dentes hígidos / Abstract: The indirect restorations are an interesting restoration procedure in the pediatric dentistry clinic, because this leads to a reduced chairside time, besides would decrease polymerization shrinkage due to the resin luting agent lower volume. To endodontically treated teeth, the performance of adhesive restorations has already not been established, and this is extremely important since if restorations upon crowns failures, the pulp therapy can be lost. Then, the objectives presented in the dissertation form based in two articles were: (1) to evaluate the earlier marginal adaptation of onlay composite restorations in primary teeth subjected or not to 1% sodium hypochlorite (1% NaOCl) irrigation and bonded with two types of resin luting agents (EnForce e Rely X); (2) to evaluate the compressive strength of experimental groups studied in the first research and compare them with the sound teeth, besides to evaluate the types of fractures regarding to severity degree. In the first study, the sample was accomplished by forty sound molars restored with indirect onlay composite restorations. The teeth were divided into groups according the two factors of variations established in this study: 1% NaOCl irrigation and resin luting agents (EnForce and Rely X). To analyze the marginal adaptation a dye solution was applied upon restorations margins, and the dyed margins were considered as marginal gaps presence. TheImage Tool 3.0 software was used to measure the linear length. In the second study, the same sample of the study 1 was used with the addition of the control group accomplished the sound teeth, with the total of 50 teeth. All specimens were subjected to compression mechanic test, and the fractures types were macroscopically classified related to the severity degree. In the first study, there were no statistically difference related quantity of gaps among the groups (p>0.05), however, some groups showed the relative risk tendency of no gap higher than others, and the group treated with NaOCl and fixed EnForce (RR=1.56) produced the higher relative risk tendency. In the second study, there were no statistically differences related to compressive force values among any studied groups (p>0.05), consequently, the experimental groups had similar values to sound teeth. Concerning the severity of fractures, the experimental groups showed the most severe types of fractures, while the control group showed the lower severe types. Then, the composite indirect restored technique showed acceptable earlier marginal adaptation and recovery of the compressive strength of teeth with complex prepares and submitted to endodontic irrigation procedure / Mestrado / Materiais Dentarios / Mestre em Materiais Dentários

Orientador: Luiz Andre Freire Pimenta / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-07-24T01:11:58Z (GMT). No. of bitstreams: 1 Saboia_VicentedePauloAragao_M.pdf: 3642627 bytes, checksum: 3810c206c50b67463e5e76e570894df6 (MD5) Previous issue date: 1998 / Resumo: O objetivo deste trabalho foi verificar os efeitos remoção do colágeno na resistência ao cisalhamento de dois sistemas adesivos de frasco único e examinar a micromorfologia da dentina, antes e após o teste de cisalhamento, em lupa estereoscópica e MEV. Foi usado como substrato dentina planificada de terceiros molares recém-extraídos e armazenados em formal a 10% (pH neutro). Foram usados os adesivos Prime & Bond 2.1 (PB-Dentsply) e Single Bond (SB-3M). Nos grupos controle (1 e 3), após aplicação da ácido fosfórico a 37%, os adesivos foram aplicados de acordo com as instruções do fabricante, enquanto que nos grupos experimentais (2 e 4), após o condicionamento ácido, foi aplicada uma solução de hipoclorito de sódio a 10% (H), por 1 minuto, para remover o colágeno exposto pelo condicionamento ácido. Foram cqnfeccionados cilindros de 3 mm de diâmetro por 5 mm de altura com resina composta Z-100 (3M). Após 24 horas em ambiente úmido a 37 °e, foi realizado o teste mecânico de cisalhamento com velocidade de 0,5 mm/min. Os resultados explorátórios e do Teste de Kruskal-Wallis podem ser observados na tabela abaixo. ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The purpose of this study was to evaluate the effect of removing collagen using Single Bond-3M (SB) according to the manufacturer's to four groups and on the shear bond strength for two single-bottle adhesives systems and to examine the dentin surfaces after shear test. The buccal and lingual surfaces of 80 extracted human third molars were ground to expose dentin, then polished with 320, 400 and 600-grit aluminum oxide. Teeth were randomly assigned received the following treatments: group 1, samples were conditioned with 37% phosphoric acid , rinsed and left moist, Prime & Bond 2.1-Dentsply (PB) adhesive was applied according to manufacturer's directions, and restorative Z100 (3M) composite resin was bonded to the dentin surface; group 2, the same procedures were followed as for group 1 except the surfaces were treated with 10% NaOCI for 1 minute, after acid conditioning; group 3, the same technique was followed as for group 1 , recommendations; group 4, the same procedure was followed for group 2, using Single Bond. The specimens were stored. in humidity at 37°C for 24 hours and tested in a shear mode at a crosshead speed of 0,5 mm/minute. The median of results were: G2=21,84, G3=15,99, G1=15,02 and G4=13,82. The Kruskal-Wallis test and multiple comparisons were used for statistical analysis of the data. A 1 minute exposure of dentin to 10% NaOCI following acid conditioning resulted in significant increase on the dentin shear bond strength for Prime & Bond 2.1 (group 2). The same treatment for Single Bond (group 4) resulted in significant reduction on the values of adhesion. Groups 1 and 3 were not statistically different from each other. Group 2 showed more dentin-cohesive failures than the other groups. Under SEM observations, there were morphological differences between the groups treated with NaOCI and those that did not received this treatment / Mestrado / Dentística / Mestre em Clínica Odontológica

Orientador: Fernanda Miori Pascon / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T04:03:41Z (GMT). No. of bitstreams: 1 Girotto_AlineCarvalho_M.pdf: 1616855 bytes, checksum: 11bb1dc52c1940120b0da6f0e2d4b9db (MD5) Previous issue date: 2015 / Resumo: O objetivo foi avaliar o efeito de uma solução antioxidante (tiossulfato de sódio a 5%) na resistência da união (RU) da dentina da câmara pulpar tratada com duas concentrações de hipoclorito de sódio (NaOCl) e diferentes sistemas adesivos. Quarenta e oito dentes bovinos foram selecionados, seccionados, para remoção das raízes e exposição da câmara pulpar, e foram divididos aleatoriamente em 16 grupos de acordo com o tratamento da superfície dentinária: NaOCl a 1%; NaOCl a 1% + tiossulfato de sódio a 5%; NaOCl a 5,25%; NaOCl a 5,25% + tiossulfato de sódio a 5% e do sistema adesivo: Single Bond UniversalTM (3M/ESPE) - técnica convencional, Single Bond UniversalTM (3M/ESPE) - técnica autocondicionante, Adper ScotchbondTM Multi-Purpose (3M/ESPE) e ClearfilTM SE Bond (Kuraray). As soluções irrigadoras foram utilizadas por 30 minutos e a solução antioxidante por 1 minuto, após a irrigação. Os dentes foram seccionados no sentido mésio-distal, resultando em duas hemi-espécimes que foram restauradas com compósito Filtek- Z350TM (3M/ESPE). Após 24 horas, os corpos-de-prova foram submetidos à microtração e foram avaliados em microscopia eletrônica de varredura (75x), quanto ao padrão de fratura (falhas adesivas; coesivas em dentina; coesivas em resina; mistas). Os dados foram convertidos em Mpa e submetidos aos testes Shapiro-Wilk, ANOVA três fatores e teste de Tukey (?=5%). Para o grupo tratado com NaOCl a 1%, maiores valores de RU foram observados para o ClearfilTM quando comparado aos demais adesivos (p<0,01). Quando associou-se a solução antioxidante, o grupo ScotchbondTM apresentou maiores valores de RU comparados aos demais grupos (p?0,01). Após tratamento com NaOCl a 5,25%, não houve diferença entre os sistemas adesivos (p>0,05). A aplicação do antioxidante após o tratamento com NaOCl a 1% e 5,25% associado ao ScotchbondTM, foi capaz de aumentar significativamente a RU. Para o sistema adesivo Single Bond UniversalTM (técnica convencional) os maiores valores de RU foram observados para o grupo tratado com NaOCl a 1% associado ao tiossulfato. (p<0,05). Entretanto, para Single Bond UniversalTM (técnica autocondicionante) e para ClearFilTM, maiores valores de RU foram observados quando da utilização do NaOCl a 1%, diferindo significativamente dos grupos tratados com NaOCl a 5,25% (p<0,01). Com relação ao ScotchbondTM, maiores valores foram observados após o tratamento com NaOCl a 1% associado ao antioxidante, seguido dos grupos: NaOCl a 1% e NaOCl a 5,25% associado ou não ao antioxidante. NaOCl a 5,25% utilizado sozinho apresentou os menores valores de RU. Maior porcentagem de falha adesiva foi observada para os grupos tratados com NaOCl a 1% + Single Bond UniversalTM, em ambas as técnicas, NaOCl a 1% + antioxidante + Single Bond UniversalTM na convencional e NaOCl a 5,25% + todos os sistemas adesivos. Para Single Bond UniversalTM - técnica autocondicionante, ClearfilTM e ScothBondTM foram observadas maiores porcentagens de falhas mistas. Conclui- se que o efeito do tiossulfato de sódio a 5% na RU da dentina da câmara pulpar, tratada com NaOCl foi dependente do sistema adesivo utilizado, sendo que para ambas as concentrações o tiossulfato foi capaz de aumentar a RU quando o sistema adesivo ScotchbondTM foi utilizado / Abstract: The aim of this study was to evaluate the effect of an antioxidant solution (5% sodium thiosulfate) on the microtensile bond strength (µTBS) between the pulp chamber dentin treated with two concentrations of sodium hypochlorite (NaOCl) and different adhesive systems. Forty eight bovine incisors were selected, sectioned horizontally to remove the roots and expose the pulp chamber and randomly divided into 16 groups according to dentin surface treatment: 1% NaOCl; 1% NaOCl + 5% sodium thiosulfate; 5.25% NaOCl; 5.25% NaOCl + 5% sodium thiosulfate and to the adhesive system: Single Bond UniversalTM - etch-and-rinse technique, Single Bond UniversalTM - self-etch technique (3M/ESPE), Adper ScotchbondTM Multi- Purpose (3M/ESPE) and ClearfilTM SE Bond (Kuraray). The irrigation solutions were applied for 30 minutes and the antioxidant solution for 1 minute, after irrigation. The teeth were sectioned into mesial-distal direction, resulting in two halves that were restored with the composite resin Filtek-Z350TM (3M/ESPE). After 24 hours, sticks were obtained and submitted to the µTBS test and they were evaluated by scanning electron microscopy (x75), and classified according the failure pattern (adhesive failure, cohesive in dentin, cohesive in resin and mixed). Data were converted to Mpa and submitted to Shapiro-Wilk, three-way ANOVA and Tukey tests (a=5%). In the group treated with 1% NaOCl, higher µTBS values were observed for ClearfilTM when compared to other adhesive systems (p<0.01). When 5% sodium thiosulfate was used after 1% NaOCl, ScotchbondTM showed higher µTBS compared to other groups (p?0.01). After treatment with 5.25% NaOCl, there was no difference between the adhesive systems (p>0.05). The application of the antioxidant after treatment with 1% NaOCl and 5.25% associated to ScotchbondTM was able to significantly increase the µTBS. For the Single Bond UniversalTM (etch-and-rinse technique) highest µTBS were observed when using 1% NaOCl with the antioxidant (p<0.05). However, for Single Bond UniversalTM (self-etching technique) and ClearFilTM highest µTBS were observed when using the 1% NaOCl, differing significantly from the groups treated with 5.25% NaOCl (p<0.01). With respect to ScotchbondTM, higher µTBS values were observed following treatment with 1% NaOCl associated with the antioxidant, followed by groups: 1% NaOCl, 5.25% NaOCl associated with the antioxidant. NaOCl 5.25% used alone had the lowest. Higher percentage of adhesive failure was observed for the groups treated with 1% NaOCl + Single Bond UniversalTM in both techniques, 1% NaOCl + antioxidant + Single Bond UniversalTM etch-and-rinse technique, and 5.25% NaOCl + all adhesive systems. To Single Bond UniversalTM - self-etching technique, ClearfilTM and ScothBondTM were observed higher percentages of mixed failures. It could be concluded that the effect of 5% sodium thiosulfate, in the µTBS of pulp chamber dentin treated with NaOCl, it was adhesive system dependent and for both NaOCl concentrations, the thiosulfate was able to increase µTBS when ScotchbondTM adhesive system was used / Mestrado / Materiais Dentarios / Mestra em Materiais Dentários

Orientador: Marcia Carneiro Valera / Coorientador: Carlos Henrique Ribeiro Camargo / Banca: Cláudio Antonio Talge Carvalho / Banca: Marco Antônio Húngaro Duarte / Resumo: Os objetivos deste estudo foram: Artigo 1 - Analisar a extrusão apical de hipoclorito de sódio (NaOCl), debris e sua citotoxicidade após o preparo dos canais radiculares utilizando NaOCl líquido ou gel. Artigo 2- avaliar a dissolução de matéria orgânica do NaOCl líquido e gel, e a limpeza das paredes dentinárias após a instrumentação; Métodos: Artigo 1 - A avaliação da extrusão apical de NaOCl e debris foi feita pela espectrofotometria do conteúdo extruído após o preparo biomecânico. A citotoxicidade foi avaliada pela resposta de culturas celulares de fibroblastos de ligamento periodontal (PDFL) frente as soluções irrigadoras extruídas, pelo teste XTT para análise da viabilidade celular. Para isso, oitenta dentes foram instrumentados com limas Reciproc #25 e #40 (VDW Munique, Alemanha) e utilizado NaOCl gel e líquido ativados por ultrassom. Os dados foram analisados estatisticamente pelo teste de ANOVA e as diferenças estatísticas pelo teste de Tukey e Dunn (p<0,05). Artigo 2 - A dissolução de matéria orgânica foi realizada usando cubos de carne com tamanho e peso determinado, os quais foram deixados em contato com 1 mL das amostras dos seguintes grupos: NaOCl gel 3% (ChlorCid V); NaOCl gel 3%(VIM); NaOCl líquido 2,5%; NaOCl líquido 5,25%; Solução fisiológica estéril (SF) (controle) por um período de 3 min, os fragmentos foram removidos e pesados novamente para quantificar a matéria orgânica não dissolvida. A comprovação da limpeza das paredes dos canais foi avaliada através ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objectives of this study were: Article 1 - Analyze the apical sodium hypochlorite (NaOCl) extrusion, debris and it's cytotoxicity after the root canals preparation using liquid or gel NaOCl. Article 2 - Evaluate the tissue dissolution of NaOCl liquid and gel, and it's cleaning efficiency of dentin walls after instrumentation; Methods: Article 1 - The evaluation of the apical extrusion of NaOCl and debris was done by the spectrophotometry of the extruded contents after the biomechanical preparation. Cytotoxicity was evaluated by the cell cultures response of periodontal ligament fibroblasts (PDFL) against extruded irrigation solutions by the XTT test for cell viability analysis. For this, eight teeth were instrumented with Reciproc # 25 and # 40 files (VDW Munich, Germany) and used NaOCl gel and liquid activated by ultrasound. Data were analyzed statistically by the ANOVA test and the statistical differences by the Tukey and Dunn test (p <0.05). Article 2 - The dissolution of organic matter was carried out using meat cubes of determined size and weight, which were left in contact with 1 mL of samples from the following groups: NaOCl gel 3% (ChlorCid V); NaOCL gel 3% (VIM); NaOCl liquid 2.5%; NaOCl liquid 5.25%; Sterile physiological solution (SP) (control) for a period of 3 min, the fragments were removed and weighed again to quantify the undissolved organic matter. The verification of the cleansing of the canal walls was evaluated through the SEM and the stereomicroscopy ... (Complete abstract click electronic access below) / Mestre

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Au niveau industriel, l'accès aux acides azélaïque et pélargonique, composés à forte valeur ajoutée, est possible grâce à une réaction d'ozonolyse de l'acide oléïque. Cependant, cette méthode présente certains désavantages sur le plan écologique. Le but de cette étude a donc été de développer une méthode alternative à ce procédé industriel, visant à limiter autant que possible les impacts écologiques, directs ou indirects, lors de la synthèse des acides azélaïque et pélargonique. Nous avons ainsi montré qu'un clivage en deux étapes peut être préférable à un clivage oxydant en une étape. Notre procédé propose ainsi, dans un premier temps, une dihydroxylation de la double liaison d'acides gras par une méthode connue, laquelle est suivie par un clivage oxydant en présence d'hypochlorite de sodium. Ce nouveau procédé mis au point au sein du laboratoire présente l'avantage de ne nécessiter l'emploi ni de métaux de transition, ni de solvant organique. Nous avons par la suite étudié l'hypochlorite de sodium afin de déterminer son rôle et son mode d'action dans la réaction de clivage de diols vicinaux / Industrial production of two high added value compounds called pelargonic acid and azelaic acid is made possible by the ozonolysis reaction of oleic acid. However, this method has numerous disadvantages in term of ecological impact. In this dissertation, we present an alternative to the current industrial process in order to lower direct or indirect negative environmental impacts when synthetizing azelaic and pelargonic acids. At first we demonstrate that a two-step oxidative cleavage may be preferable to a one-step cleavage. Then we present in details a novel synthesis method which starts with the dihydroxylation of the fatty acids double bond using a well known method, followed by the oxidative cleavage in presence of sodium hypochlorite. One notes that this original fabrication process developed in our laboratory does not require to use transition metals nor organic solvents. As a complement to this work, we have subsequently studied the sodium hypochlorite to determine its role and operating mode in the vicinal diols cleavage reaction

Lors de leur utilisation à l’échelle industrielle, les membranes polymères de filtration sont régulièrement soumises à des sollicitations chimiques lors des étapes de nettoyage et de désinfection. Bien que ces opérations restent inévitables pour restaurer les performances des membranes et prévenir la prolifération des micro-organismes, il s’avère néanmoins qu’elles conduisent à un vieillissement prématuré des membranes en conduisant à l’altération de leurs performances de filtration. L’objectif de cette thèse était d’étudier l’impact de l’hypochlorite de sodium, agent de nettoyage et de désinfection largement utilisé en industrie, sur les membranes en polyéthersulfone (PES) / polyvinylpyrrolidone (PVP). Des mesures électrocinétiques ont mis en évidence la dégradation du PES bien qu’il soit considéré comme un polymère très résistant chimiquement. Cette dégradation se produit par deux mécanismes distincts en fonction du pH de la solution d’hypochlorite de sodium : (i) la coupure de chaines du PES, principalement sous l’action de l’espèce HClO et (ii) l’hydroxylation du cycle aromatique du PES par les radicaux °OH formés au sein de la solution d’hypochlorite de sodium. La dégradation de la PVP par ouverture du cycle et son départ partiel de la membrane ont également été confirmés. Les expériences menées conjointement sur des membranes en PES pur et en PES/PVP avec différentes concentrations de PVP ont montré que la dégradation du PES par coupure de chaines se produit indépendamment de la concentration de la PVP dans la membrane. Par contre, la présence de la PVP favorise le mécanisme d’hydroxylation des cycles aromatiques du PES. Par ailleurs, le mécanisme de coupure de chaines du PES se révèle être le principal responsable de la détérioration des performances de filtration des membranes. Dans les conditions de vieillissement appliquées dans cette étude, ni l’hydroxylation du PES ni la dégradation de la PVP ne semblent jouer un rôle important dans la dégradation des propriétés de rétention des membranes. Enfin, la structure des membranes est fortement altérée sous l’action de l’hypochlorite de sodium, les modifications structurales étant plus importantes pour les membranes contenant de la PVP. / During industrial operations, filtration polymer membranes are regularly chemically-stressed during cleaning and disinfection steps. Although these latter are still unavoidable to restore the membrane performance and to prevent the proliferation of microorganisms, they lead, however, to membrane premature ageing, which impairs the membrane separation properties. The aim of this thesis was to investigate the impact of sodium hypochlorite, a widely used cleaning and disinfection agent, on polyethersulfone (PES) / polyvinylpyrrolidone (PVP) membranes. Electrokinetic measurements highlighted the degradation of PES, although the chemical resistance of this latter is well-acknowledged. The degradation of PES occurred through two distinct mechanisms depending on the pH of the sodium hypochlorite solution: (i) the PES-chain scission, which was found to result mainly from the HClO species, and (ii) the hydroxylation of the PES aromatic rings by the °OH free radicals that are formed in the sodium hypochlorite solution. Moreover, the degradation of PVP by a ring opening mechanism and its partial release from the membrane were confirmed. Experiments carried out with pure PES membranes as well as with PES / PVP membranes with different PVP contents showed that the PES-chain scission mechanism occurred whatever the PVP concentration. On the other hand, the presence of PVP was found to promote the hydroxylation of the PES aromatic rings. Furthermore, the PES-chain scission mechanism appeared to play the major role in the worsening of the membrane filtration performance. Under the ageing conditions of this study it seems that neither the PES hydroxylation nor the PVP degradation play a significant role in the worsening of the membrane rejection properties. Finally, the membrane structure was found to be substantially altered by the action of sodium hypochlorite, especially for membranes containing PVP.

Ce travail est consacré à l’étude de l’impact des lavages chimiques à l’hypochlorite de sodium (NaOCl) effectués sur des membranes polymères polyéthersulfone (PES)/polyvinylpyrolidonne (PVP) (95%/5%) utilisées pour la filtration de l’eau ou du lait. Sur les sites d’exploitation les lavages chimiques sont nécessaires pour maintenir les propriétés de filtration des membranes qui se colmatent au cours de leur utilisation. L’objectif de cette étude est de déterminer les mécanismes de dégradation de ces deux polymères au contact de l’agent nettoyant, puis de corréler ces évolutions aux changements de propriétés macroscopiques des membranes en réalisant une analyse multi-échelle. Dans un premier temps, l’étude de l’impact de NaOCl sur des polymères modèles, le PES d’une part et la PVP d’autre part, a montré que la PVP s’oxyde lorsqu’elle est dissoute dans NaOCl ce qui n’est pas le cas de films de PES. A partir de l’identification des produits d’oxydation, un mécanisme d’oxydation radicalaire de la PVP mettant en jeu les radicaux hydroxyles provenant de la solution de NaOCl a été proposé. Dans un deuxième temps, afin de s’affranchir de l’hétérogénéité des membranes PES/PVP, des films de mélanges modèles PES/PVP à différents pourcentages de PVP ont été préparés. Leur immersion dans une solution de NaOCl provoque non seulement l’oxydation de la PVP mais aussi celle du PES montrant sans ambiguïté l’effet pro-dégradant de la PVP sur le PES. Dans un troisième temps, il a été montré que le vieillissement des membranes PES/PVP peut être explicité à partir des résultats obtenus sur les mélanges modèles, et que l’évolution de la structure chimique de la PVP pouvait être corrélée avec la perte des propriétés mécaniques des membranes permettant de faire le lien entre l’évolution de la structure chimique et la perte des propriétés macroscopiques. Il apparait donc au final que l’additif ajouté au PES pour rendre les membranes hydrophiles est le talon d’Achille de la structure. Le suivi de l’oxydation de la PVP contenue dans les membranes exposées à NaOCl a été proposé pour servir de marqueur moléculaire de vieillissement. / This work was devoted to the study of the impact that chemical cleaning with sodium hypochlorite (NaOCl) has on polyethersulfone (PES)/polyvinylpyrrolidone (PVP) (95%/5%) membranes, commonly used for water and milk filtration processes. In onsite plants, chemical cleanings are widely used to maintain membranes filtration properties. The aim of this thesis is to determine the degradation mechanisms of these two polymers in contact with NaOCl and to correlate this information with the evolution of the macroscopic properties of the membrane through a multi scale analysis. Firstly, the study of NaOCl impact on both PVP and PES, treated separately as “model polymers”, showed us that dissolved PVP is oxidised, whereas PES film remains stable. Thanks to the identification of PVP oxidation products, a radical degradation mechanism by means of hydroxyl radicals from NaOCl solution has been proposed. Secondly, in order to overcome membrane heterogeneities, several films with different PES/PVP ratios were prepared by varying the amount of PVP. The immersion of these films in NaOCl solutions provoked the oxidation of both PVP and PES, allowing us to clearly identify the degrading effect that PVP has in PES oxidation. Thirdly, the evolution of PVP chemical structure was correlated with the loss of the membrane mechanical properties, demonstrating that PVP, used as an additive (5%), is the weak point of PES/PVP membranes. The monitoring of PVP oxidation in membranes in contact with NaOCl was proposed as a molecular marker of ageing.