• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 4
  • 3
  • Tagged with
  • 10
  • 6
  • 6
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Substitution des Isocyanates dans les Polyuréthanes pour l’Elaboration de Matériaux Adhésifs et Expansés / Substitution of isocyanates in polyurethanes for the elaboration of adhesive and porous materials

Cornille, Adrien 24 November 2016 (has links)
A l'heure actuelle, de nombreuses entreprises commercialisent des matériaux polyuréthanes pour diverses applications. Le polyuréthane se place au sixième rang des polymères les plus produits au monde. Néanmoins, ces matériaux sont préparés à partir de monomères dangereux : les isocyanates. Ces derniers sont toxiques ou même parfois CMR (Cancérigène, Mutagène, Reprotoxique) et représentent un danger pour l'environnement, le formulateur et l'utilisateur. Pour protéger leurs employés et consommateurs et dans le cadre de la législation REACH, Bostik et Arkema, les deux entreprises du consortium CYRRENAS financé par l’Agence Nationale de la Recherche, visent à substituer les isocyanates dans les polyuréthanes et ainsi former des matériaux Non-Isocyanate PolyUrethane (NIPU). Parmi les différentes voies d’accès aux NIPUs, la voie novatrice carbonate cyclique/amine a été envisagée afin de synthétiser des matériaux polyhydroxyuréthanes (PHU). Une étude approfondie par des analyses spectrométriques (RMN) et thermiques (DSC) sur des réactions modèles entre des mono-carbonates cycliques et des mono-amines ont permis de mettre en évidence les paramètres influençant la réactivité ainsi que les limitations de cette technologie. Ce manuscrit s’intéresse également à l’élaboration de matériaux PHU, à leurs propriétés mécaniques, thermomécaniques et d'adhésion sur différents supports. Le polyuréthane est également très largement employé sous forme de mousses flexibles et rigides qui représentent 2/3 du marché mondial des matériaux polyuréthane. Dans cette optique, les premières mousses PHUs ont été élaborées et caractérisées. Enfin, dans le but de pallier la limitation de la synthèse des PHUs, une nouvelle approche de formulation de matériaux a été mise au point à partir de pré-polymères amino-téléchéliques contenant des groupements hydroxyuréthanes et des extendeurs de chaîne bio-sourcés. Les matériaux résultant de cette formulation sont appelés H-NIPUs. / Polyurethane ranks as the sixth most produced polymer in the world. Nevertheless, these materials are obtained from harmful monomers: isocyanates. Isocyanates are toxic and sometimes CMR (Carcinogenic, Mutagenic, Reprotoxic) and represent a danger for the environment, the formulator and the final user. To protect their employees and consumers and in the context of the REACH regulation , Bostik and Arkema, the two companies of the consortium CYRRENAS funded by the Agence Nationale de la Recherche, target the substitution of isocyanates in polyurethanes and thus the production of Non-Isocyanates Polyurethane (NIPU) materials. Among the different access routes to NIPUs, the innovative cyclic carbonate/amine way was considered in order to synthesize polyhydroxyurethane (PHU) materials. A detailed study by spectrometric (NMR) and thermic (DSC) analyses on model reactions between mono-cyclic carbonates and mono-amines allowed to bring to light the parameters influencing the reactivity as well as the limitations of this technology. This manuscript also focuses on the elaboration of flexible and rigid PHU materials, on their thermal, mechanical, thermomechanical and adhesive properties on different substrates. The polyurethane is also very largely employed in flexible and rigid foams which represent 2/3 of the worldwide market. In this context, the first PHU foams were synthesized and thermally and mechanically characterized. Finally, with the objective to circumvent the limitations of the PHU synthesis, a new approach for the formulation of polyurethanes without isocyanates was developed from aminotelechelic prepolymers containing hydroxyurethane moieties and biobased epoxidized compounds used as chain extenders. The materials resulting from this formulation are called H-NIPUs.
2

New challenges in the synthesis of non-isocyanate polyurethanes / Nouveaux défis dans la synthèse de polyuréthanes sans isocyanates

Bossion, Amaury 18 December 2018 (has links)
Parmi tous les plastiques, les polyuréthanes (PUs) représentent la sixième classe de polymères la plus utilisée au monde. Ils sont synthétisés industriellement par réaction entre un diol et un diisocyanate, en présence d'un catalyseur métallique et d’un solvant organique.Néanmoins, cette synthèse présente d’importants problèmes environnementaux et de santé.Afin de s’affranchir de ces composés toxiques, les progrès dans ce domaine ont conduit à un certain nombre de procédés sans isocyanates. Néanmoins, ces procédés doivent faire face à de nombreux défis (propriétés physiques, masses molaires, réactions secondaires, etc.), afin de concurrencer les polyuréthanes classiques. Par conséquent, une partie de ce manuscrit est dédiée à une étude rationnelle de l'influence de catalyseurs organiques, tels que le TBDou P4, non seulement sur la cinétique de polymérisation de l’aminolyse de carbonates biscycliques,mais aussi sur la structure et les propriétés des PUs résultants. Par la suite, et afin de limiter l’utilisation de composés organiques volatiles, des dispersions aqueuses de polyuréthanes sans isocyanates ont été obtenues en adaptant : 1) le procédé acétone à l’aminolysis de carbonates bis-cycliques et 2) la polymérisation interfaciale à la polycondensation de dicarbonates linéaires avec des diamines. / Among all plastic materials, polyurethanes (PUs) represent the 6th most popularly usedpolymers in the World. They are industrially synthesized by the reaction between a diol and adiisocyanate, in the presence of a metal catalyst and an organic solvent. Nevertheless, thissynthesis presents important environmental and health problems. In order to replace thesetoxic compounds, advances in this field have led to a number of isocyanate-free processes.However, these processes have to face many challenges (physical properties, molarmasses, side reactions, etc.), in order to compete with conventional polyurethanes.Therefore, part of this manuscript is dedicated to a rational study of the influence oforganocatalysts, such as TBD or P4, not only on the polymerization kinetics of the aminolysisof bis-cyclic carbonates, but also on the structure and properties of the resulting PUs.Subsequently, and in order to limit the use of volatile organic compounds, aqueousdispersions of non-isocyanate PUs were obtained by adapting: 1) the acetone process to theaminolysis of bis-cyclic carbonates and 2) the interfacial polymerization to thepolycondensation of linear dicarbonates with diamines.
3

Résines alkydes biosourcées uréthanisées sans isocyanate par réticulation non-oxydative / Biobased non-isocyanate urethanized alkyd resins with non-oxidative crosslinking mechanism

Sonnati, Matthieu 30 September 2013 (has links)
Les résines alkydes sont les principaux liants des peintures et vernis modernes. Ces polymères sont obtenus par polycondensation de polyacides, polyols, acides gras et monoacides. L’engouement croissant pour le développement durable pousse à la transition de produits pétrosourcés vers des produits biosourcés, à coûts et performances similaires. Pour les alkydes qui utilisent déjà en partie des matières premières renouvelables (acides gras, polyols), le challenge consiste à substituer les composants pétrosourcés restants tels que les dérivés phtaliques et benzoïques. Après un état de l’art sur les alkydes, nous avons étudié les implications liées à la substitution de ces dérivés. Plusieurs résines alkydes biosourcées furent synthétisées et caractérisées par des mesures physico-chimiques (SEC, DSC, rhéomètre). Les peintures alkydes conventionnelles sèchent chimiquement par un mécanisme oxydatif qui requiert des sels de cobalt pour advenir en moins de 6 h. A cause de leur toxicité, ces sels sont sous pression par REACH. Nous avons proposé un mécanisme alternatif de réticulation non-oxydatif basé sur la réaction entre les groupes 2-oxo-1,3-dioxolane (ODO) et les amines primaires. La réaction modèle entre le carbonate de glycérol et l’éthylenediamine nous a permis de comprendre la viabilité de ce mécanisme de réticulation. La création de groupes ODO a d’abord été étudiée sur des huiles végétales afin de déterminer les conditions optimales et confirmer les possibles réactions d’oligomérisation. Des alkydes portant ces groupes ODO ont pu être synthétisées et caractérisées, puis converties en résines alkydes uréthanisées sans isocyanate par réaction avec des diamines. / Alkyd resins are the major binders used in surface coatings today. They are obtained by polycondensation of polybasic acids, polyols, fatty acids and monobasic acids. The raising sustainability awareness is pressuring for the transition from petrobased to biobased products with equivalent costs and performances. While conventional alkyd resins have high content in renewable raw materials such as fatty acids and polyols, replacement of petrobased raw materials such as phthalate and benzoic derivatives remained a challenge. After reviewing the current state-of-the-art regarding conventional alkyd resins, we focused on understanding the specific issues related to the synthesis of biobased alkyd resins. Several biobased alkyd resins were synthesized and characterized using techniques such as SEC, DSC and rheometer. Conventional alkyd paints chemically dry through an oxidative mechanism, which requires cobalt salts to occur in less than 6 h. These salts are under the scope of REACH because of their toxicity. As a possible alternative, we proposed a non-oxidative crosslinking mechanism based on the reaction of 2-oxo-1,3-dioxolane (ODO) groups and primary amines. This crosslinking mechanism was first studied with the model reaction between glycerol carbonate and ethylenediamine. The functionalization of ODO groups on vegetable oils was then studied as model molecule of alkyd resins, enabling the determination of optimal reaction conditions and that oligomerization occurs as a side reaction. Alkyd resins bearing ODO groups were then synthesized and characterized, then converted into non-isocyanate urethanized alkyd resins by reaction with diamines.
4

CO2 como matéria prima: materiais híbridos do tipo uretanosil obtidos a partir de monômeros de poli(dimetil siloxano) e bisfenol A / CO2 as raw material: hybrid materials of the urethanosil type obtained from poly (dimethyl siloxane) and bisphenol A

Alves, Átila Nascimento 20 August 2018 (has links)
Materiais dielétricos flexíveis e filmogênicos são essências para a produção de diversos dispositivos tecnológicos, tais como Organic Light Emiting Diodes (OLED), Transistores de Efeito de Campo (FET do Inglês Field Emission Transistor) ou fotovoltaicos orgânicos (OPV do Inglês Organic Photovoltaics). Dentro deste contexto, é importante salientar o esforço de desenvolver rotas sintéticas mais sustentáveis baseadas em matérias-primas e processos mais amigáveis ao meio ambiente. No Grupo de Química de Materiais Híbridos e Inorgânicos (GQMATHI) há mais de dez anos se pesquisa rotas sintéticas de preparação de oligômeros e polímeros de uretanas usando CO2 como matéria-prima. Assim, são sintetizados os materiais classificados como polihidroxi-uretânicos, que são obtidos a partir do monômero bis-ciclocarbonato de polidimetilsiloxano (CCPDMS) mediante a reação de polimerização por abertura de anel (ROP - do inglês Ring Oppening Polymerization). O monômero é obtido pela reação de cicloadição de CO2 no seu respectivo epóxido: poli(dimetil-siloxano) diglicidil éter (PDMS). Neste projeto os materiais hidroxi-uretânicos foram sintetizados, utilizando tanto o CCPDMS como monômero precursor da reação, como o ciclocarbonato de bisfenol A diglicidil éter (CCDGEBA). O oligômero formado foi ensaiado em diferentes proporções destes dois ciclocarbonatos na reação frente à uma diamina (5-Amino-1,3,3-trimetilciclohexanometilamina ,IFDA). Utilizou-se como grupo terminador de cadeia o 3-aminopropiltrietóxissilano (APTS). Os ciclocarbonatos foram caracterizados por espectroscopia vibracional (FTIR) e de ressonância magnética nuclear (RMN) de 13C e 1H. Na espectroscopia vibracional a formação do grupamento ciclocarbonato foi obtida pela presença da banda de carbonila em 1790 cm-1 , enquanto na RMN os sinais do duplo dubleto próximo de 4,5 ppm (1H) e o pico em 154 ppm (13C) foram interpretados como sinais carcaterísticos do grupo ciclocarbonato. O material oligomérico sintetizado a partir dos ciclocarbonatos foi caracterizado por análise termogravimétrica (TGA), calorimetria diferencial de varredura (DSC), análise dinâmico-mecânica (DMA) bem como filmes dos mesmos foram preparados via spin coating. Os filmes foram caracterizados eletricamente por medidas de espectroscopia de impedância, visando avaliar a possibilidade do material ser utilizado como camada dielétrica em transístores orgânicos do tipo FET. Visando um melhor desempenho do material hidroxi-uretânico nesta aplicação o dióxido de titânio (constante dielétrica (ε) ≈ 100) foi introduzido na matriz polimérica. Assim sendo, a introdução desta cerâmica classificará o material formado como um material compósito do tipo híbrido inorgânico-orgânico. Este híbrido também foi caracterizado por espectroscopia de impedância revelando um aumento da constante dielétrica, porém um aumento da perda dielétrica também foi observada para o híbrido. / Flexible and film-forming dielectric materials are essential for the production of various technological devices, such as Organic Light Emitting Diodes (OLED), Field Effect Transistors (FETs) or organic photovoltaics (OPVs). Within this context, it is important to highlight the effort to develop more sustainable synthetic routes based on raw materials and more environmentally friendly processes. In the Group of Chemistry of Hybrid and Inorganic Materials (GQMATHI) more than ten years ago, synthetic routes for preparation of oligomers and polymers of urethanes using CO2 as raw material have been investigated. Thus, materials classified as polyhydroxy urethanes, which are obtained from the bis-cyclocarbonate monomer of polydimethylsiloxane (CCPDMS) are synthesized by the Ring Oppening Polymerization (ROP) reaction. The monomer is obtained by the cycloaddition reaction of CO2 in its respective epoxide: poly (dimethylsiloxane) diglycidyl ether (PDMS). In this project the hydroxy urethane materials were synthesized, using two different types of precursor monomer : the CCPDMS and bisphenol A diglycidyl ether cyclocarbonate (CCDGEBA). The oligomer formed was tested in different ratios of these two cyclocarbonates in the reaction against a diamine (5-Amino-1,3,3-trimethylcyclohexanemethylamine (IFDA)). The aminopropyltriethoxysilane (APTS) was used as the chain terminator group. After the synthesis of the cyclocarbonates, characterizations were made by vibrational spectroscopy (IR) and nuclear magnetic resonance (NMR) of 13C and 1H. The successful formation of the cyclocarbonate was confirmed by the 1790 cm-1 peak in the vibrational spectroscum as well as by the dublet near 4.5 ppm (1H NMR) and the singlet at 154 ppm (13 C NMR). The oligomeric hydroxyurethane synthesized from the cyclocarbonates reaction with IFDA and APTS was characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic-mechanical analysis (DMA) and films were prepared by spin coating. The electrical characterization of the films was made by impedance spectroscopy, aiming to evaluate its application on organic FET´s as adielectric layer . In order to improve the performance of the hydroxy urethane material for this application, titanium dioxide (dielectric constant (ε) ≈ 100) was incorporated into the oligomer matrix, thus an hybrid nanocomposite material was formed. The impedance chacacterization of the hybrid was performed showing higher dielectric constant for this new material, although observed a higher dielectric loss, 9 vs 0,2 ,respectively for the hydroxyurethane and the hybrid.
5

CO2 como matéria prima: materiais híbridos do tipo uretanosil obtidos a partir de monômeros de poli(dimetil siloxano) e bisfenol A / CO2 as raw material: hybrid materials of the urethanosil type obtained from poly (dimethyl siloxane) and bisphenol A

Átila Nascimento Alves 20 August 2018 (has links)
Materiais dielétricos flexíveis e filmogênicos são essências para a produção de diversos dispositivos tecnológicos, tais como Organic Light Emiting Diodes (OLED), Transistores de Efeito de Campo (FET do Inglês Field Emission Transistor) ou fotovoltaicos orgânicos (OPV do Inglês Organic Photovoltaics). Dentro deste contexto, é importante salientar o esforço de desenvolver rotas sintéticas mais sustentáveis baseadas em matérias-primas e processos mais amigáveis ao meio ambiente. No Grupo de Química de Materiais Híbridos e Inorgânicos (GQMATHI) há mais de dez anos se pesquisa rotas sintéticas de preparação de oligômeros e polímeros de uretanas usando CO2 como matéria-prima. Assim, são sintetizados os materiais classificados como polihidroxi-uretânicos, que são obtidos a partir do monômero bis-ciclocarbonato de polidimetilsiloxano (CCPDMS) mediante a reação de polimerização por abertura de anel (ROP - do inglês Ring Oppening Polymerization). O monômero é obtido pela reação de cicloadição de CO2 no seu respectivo epóxido: poli(dimetil-siloxano) diglicidil éter (PDMS). Neste projeto os materiais hidroxi-uretânicos foram sintetizados, utilizando tanto o CCPDMS como monômero precursor da reação, como o ciclocarbonato de bisfenol A diglicidil éter (CCDGEBA). O oligômero formado foi ensaiado em diferentes proporções destes dois ciclocarbonatos na reação frente à uma diamina (5-Amino-1,3,3-trimetilciclohexanometilamina ,IFDA). Utilizou-se como grupo terminador de cadeia o 3-aminopropiltrietóxissilano (APTS). Os ciclocarbonatos foram caracterizados por espectroscopia vibracional (FTIR) e de ressonância magnética nuclear (RMN) de 13C e 1H. Na espectroscopia vibracional a formação do grupamento ciclocarbonato foi obtida pela presença da banda de carbonila em 1790 cm-1 , enquanto na RMN os sinais do duplo dubleto próximo de 4,5 ppm (1H) e o pico em 154 ppm (13C) foram interpretados como sinais carcaterísticos do grupo ciclocarbonato. O material oligomérico sintetizado a partir dos ciclocarbonatos foi caracterizado por análise termogravimétrica (TGA), calorimetria diferencial de varredura (DSC), análise dinâmico-mecânica (DMA) bem como filmes dos mesmos foram preparados via spin coating. Os filmes foram caracterizados eletricamente por medidas de espectroscopia de impedância, visando avaliar a possibilidade do material ser utilizado como camada dielétrica em transístores orgânicos do tipo FET. Visando um melhor desempenho do material hidroxi-uretânico nesta aplicação o dióxido de titânio (constante dielétrica (ε) ≈ 100) foi introduzido na matriz polimérica. Assim sendo, a introdução desta cerâmica classificará o material formado como um material compósito do tipo híbrido inorgânico-orgânico. Este híbrido também foi caracterizado por espectroscopia de impedância revelando um aumento da constante dielétrica, porém um aumento da perda dielétrica também foi observada para o híbrido. / Flexible and film-forming dielectric materials are essential for the production of various technological devices, such as Organic Light Emitting Diodes (OLED), Field Effect Transistors (FETs) or organic photovoltaics (OPVs). Within this context, it is important to highlight the effort to develop more sustainable synthetic routes based on raw materials and more environmentally friendly processes. In the Group of Chemistry of Hybrid and Inorganic Materials (GQMATHI) more than ten years ago, synthetic routes for preparation of oligomers and polymers of urethanes using CO2 as raw material have been investigated. Thus, materials classified as polyhydroxy urethanes, which are obtained from the bis-cyclocarbonate monomer of polydimethylsiloxane (CCPDMS) are synthesized by the Ring Oppening Polymerization (ROP) reaction. The monomer is obtained by the cycloaddition reaction of CO2 in its respective epoxide: poly (dimethylsiloxane) diglycidyl ether (PDMS). In this project the hydroxy urethane materials were synthesized, using two different types of precursor monomer : the CCPDMS and bisphenol A diglycidyl ether cyclocarbonate (CCDGEBA). The oligomer formed was tested in different ratios of these two cyclocarbonates in the reaction against a diamine (5-Amino-1,3,3-trimethylcyclohexanemethylamine (IFDA)). The aminopropyltriethoxysilane (APTS) was used as the chain terminator group. After the synthesis of the cyclocarbonates, characterizations were made by vibrational spectroscopy (IR) and nuclear magnetic resonance (NMR) of 13C and 1H. The successful formation of the cyclocarbonate was confirmed by the 1790 cm-1 peak in the vibrational spectroscum as well as by the dublet near 4.5 ppm (1H NMR) and the singlet at 154 ppm (13 C NMR). The oligomeric hydroxyurethane synthesized from the cyclocarbonates reaction with IFDA and APTS was characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic-mechanical analysis (DMA) and films were prepared by spin coating. The electrical characterization of the films was made by impedance spectroscopy, aiming to evaluate its application on organic FET´s as adielectric layer . In order to improve the performance of the hydroxy urethane material for this application, titanium dioxide (dielectric constant (ε) ≈ 100) was incorporated into the oligomer matrix, thus an hybrid nanocomposite material was formed. The impedance chacacterization of the hybrid was performed showing higher dielectric constant for this new material, although observed a higher dielectric loss, 9 vs 0,2 ,respectively for the hydroxyurethane and the hybrid.
6

Obtenção e caracterização de poliuretanos sem o uso de isocianatos (NIPU) e com fixação de CO2 / Non-isocyanate polyurethanes\'s (NIPU) obtention and characterization with CO2 fixation

Nogueira, Rodrigo Bíscaro 22 November 2010 (has links)
Neste trabalho, foi estudada uma rota alternativa para síntese de poliuretanos sem a utilização de isocianatos (NIPU) por um processo de fabricação seguro e utilizando CO2 como insumo. A produção destes poliuretanos \"verdes\" ocorreu através da reação entre ciclocarbonatos e diaminas. A caracterização da estrutura química e a análise dos produtos da reação de formação dos poliuretanos foi possível com a utilização de espectroscopia de infravermelho com transformada de Fourier (FTIR) e espectroscopia de ressonância magnética nuclear (RMN). Foram sintetizados também os ciclocarbonatos pela reação de cicloadição de CO2 ao grupo oxirano de uma resina epóxi e o co-catalisador (resinato de zinco) utilizado na obtenção dos carbonatos cíclicos. Para otimização da formação dos ciclocarbonatos desenvolveu-se um reator de síntese, o qual permitiu a análise do rendimento da reação em função dos parâmetros de síntese controlados: pressão de CO2, temperatura do meio reacional, tempo de síntese, gaseificação da resina epóxi com CO2 (por agitação mecânica ou sistema de refluxo de CO2) e fonte de aquecimento (convencional ou utilizando radiação de microondas). A estrutura química do carbonato obtido, o rendimento e os possíveis subprodutos da reação de cicloadição também foram analisados por FTIR e RMN. / Seeking to optimize the formation of ciclocarbonates, it was developed a reactor in a closed system (no atmospheric emissions of CO2) in which the parameters of synthesis could be controlled: CO2 pressure, temperature of the reaction medium, distribution and concentration of CO2 gas bubbles in epoxy resin. The development of the ciclocarbonate synthesis\'s reactor included new systems to improve the gas-liquid contact between the reactants (aerator and CO2 reflux system) and also a heating system using microwave radiation. It were synthesized in this research, the co-catalyst (zinc resinate), the ciclocarbonate under different conditions of: pressure, temperature, synthesis time, heating source, aeration and catalyst, and \"green\" polyurethanes by an alternative route instead of the use of isocyanates, which have potential in specific applications (control of properties through chemical structure of the polymer). The result of the carbonates formation reaction was analyzed by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (RMN) to obtain the carbonates\'s chemical structure\'s, yield and the reaction\'s by-products. Non-isocyanate polyurethanes (NIPU) were obtained from a manufacturing process and secure using CO2 as an input. The characterization of the chemical structure and the yield and by-product\'s analysis of the polyurethanes formation reaction also happened by FTIR and RMN.
7

Obtenção e caracterização de poliuretanos sem o uso de isocianatos (NIPU) e com fixação de CO2 / Non-isocyanate polyurethanes\'s (NIPU) obtention and characterization with CO2 fixation

Rodrigo Bíscaro Nogueira 22 November 2010 (has links)
Neste trabalho, foi estudada uma rota alternativa para síntese de poliuretanos sem a utilização de isocianatos (NIPU) por um processo de fabricação seguro e utilizando CO2 como insumo. A produção destes poliuretanos \"verdes\" ocorreu através da reação entre ciclocarbonatos e diaminas. A caracterização da estrutura química e a análise dos produtos da reação de formação dos poliuretanos foi possível com a utilização de espectroscopia de infravermelho com transformada de Fourier (FTIR) e espectroscopia de ressonância magnética nuclear (RMN). Foram sintetizados também os ciclocarbonatos pela reação de cicloadição de CO2 ao grupo oxirano de uma resina epóxi e o co-catalisador (resinato de zinco) utilizado na obtenção dos carbonatos cíclicos. Para otimização da formação dos ciclocarbonatos desenvolveu-se um reator de síntese, o qual permitiu a análise do rendimento da reação em função dos parâmetros de síntese controlados: pressão de CO2, temperatura do meio reacional, tempo de síntese, gaseificação da resina epóxi com CO2 (por agitação mecânica ou sistema de refluxo de CO2) e fonte de aquecimento (convencional ou utilizando radiação de microondas). A estrutura química do carbonato obtido, o rendimento e os possíveis subprodutos da reação de cicloadição também foram analisados por FTIR e RMN. / Seeking to optimize the formation of ciclocarbonates, it was developed a reactor in a closed system (no atmospheric emissions of CO2) in which the parameters of synthesis could be controlled: CO2 pressure, temperature of the reaction medium, distribution and concentration of CO2 gas bubbles in epoxy resin. The development of the ciclocarbonate synthesis\'s reactor included new systems to improve the gas-liquid contact between the reactants (aerator and CO2 reflux system) and also a heating system using microwave radiation. It were synthesized in this research, the co-catalyst (zinc resinate), the ciclocarbonate under different conditions of: pressure, temperature, synthesis time, heating source, aeration and catalyst, and \"green\" polyurethanes by an alternative route instead of the use of isocyanates, which have potential in specific applications (control of properties through chemical structure of the polymer). The result of the carbonates formation reaction was analyzed by Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (RMN) to obtain the carbonates\'s chemical structure\'s, yield and the reaction\'s by-products. Non-isocyanate polyurethanes (NIPU) were obtained from a manufacturing process and secure using CO2 as an input. The characterization of the chemical structure and the yield and by-product\'s analysis of the polyurethanes formation reaction also happened by FTIR and RMN.
8

Non-isocyanate polyurethanes, polyamides and silyl modified polymers synthesized by olefin metathesis : alternative solutions to polyurethane adhesives / Polyuréthanes sans isocyanates, polyamides et polymères silylés synthétisés par métathèse d’oléfines : des solutions alternatives aux adhésifs polyuréthanes

Chauveau, Cyril 26 October 2018 (has links)
Les polyuréthanes (PUs) sont utilisés comme adhésifs depuis des décennies, mais l’utilisation d’isocyanates durant leur synthèse les place aujourd’hui dans la visée de nouvelles réglementations. Dans ces travaux, nous décrivons trois technologies alternatives potentielles aux Pus, basés sur la métathèse d’oléfines. La première technologie repose sur la synthèse de polyuréthanes sans isocyanates (NIPUs) à partir de motifs carbonate de vinylène (VC). Des polyoléfines VC2-téléchéliques ont été synthétisées par polymérisation par ouverture de cycle par métathèse / métathèse croisée (ROMP/CM) de cyclooléfines en présence d’un agent de transfert (CTA) de type VC. Cependant, la polyaddition avec une diamine a mis en évidence des reactions secondaires empêchant d’obtenir le matériaux désiré. La seconde technologie considérée est la synthèse de polyamides (PA). Des polyoléfines diazlactone (AZL)2-téléchéliques ont été synthétisées par ROMP/CM en presence d’un CTA de type AZL, puis ouvertes par une diamine. Des PAs ont ainsi été obtenus avec succès, mais en faibles quantités, ne permettant pas d’étudier leurs propriétés mécaniques ou adhésives. La dernière approche utilise les polymères silylés (SMPs). Trois types de SMPs ont été synthétisés par diverses stratégies de métathèse : des polypropylèneglycols (PPGs), des copolymères polycyclooctène (PCOE)/PPG et des copolymères polybutadiène (PBD)/PPG. La polycondensation de ces SMPs par différents systèmes catalytiques a été étudiée, ainsi que les propriétés mécaniques et adhésives des matériaux résultants. Parmi ceux-ci, les copolymères PCOE/PPG SMPs ont démontré de remarquables propriétés mécaniques et adhésives, meilleures que la plupart des SMPs commerciaux d’aujourd’hui. / Polyurethanes (PUs) have been used as adhesives for decades, but the toxic isocyanates needed for their synthesis is now on the scope of regulations. In this work, we describe three potential alternative technologies to classic PUs, based on a powerful polymerization tool: olefin metathesis. The first technology relies on the synthesis of nonisocyanate polyurethanes from vinylene carbonate (VC) functionalities. Telechelic VC polyolefins were synthesized by ring-opening metathesis polymerization/cross-metathesis (ROMP/CM) of cycloolefins with a VC chain-transfer agent (CTA). However, polyaddition attempts with a diamine evidenced side-reactions, preventing the isolation of the expected material The second technology considered is the synthesis of polyamide (PA). Following a similar strategy, telechelic azlactone (AZL) polyolefins were synthesized by ROMP/CM of cycloolefins with an AZL CTA, then, were subsequently opened by a diamine. PA were successfully obtained through this strategy, however in small quantities, thus, no mechanical nor adhesive tests were carried out. The last technology uses silyl modified polymers (SMPs). Three type of SMPs were synthesized, using diverse olefin metathesis strategies : polypropylene (PPG), polycylooctene (PCOE)/PPG copolymers and polybutadiene (PBD)/PPG copolymers. Curing of the trimethoxysilyl or triethoxysilyl groups inside these SMPs was studied using different catalytic systems, as well as the mechanical and adhesive properties of the materials obtained. Among them, PCOE/PPG copolymers displayed remarkable good mechanical and adhesive properties, better than the majority of commercial SMPs available today.
9

Substitution des isocyanates dans les polyuréthanes pour des revêtements transparents de forte épaisseur / Isocyanate substitution in polyurethane for thick transparent coatings

Blain, Marine 23 May 2016 (has links)
L'entreprise Juxta produit des résines pour des revêtements transparents de fortes épaisseurs en polyuréthane. Ces revêtements sont fabriqués à partir de deux produits dangereux : les isocyanates et un catalyseur à base de mercure. Pour protéger ses employés et consommateurs, l'entreprise Juxta a lancé un projet de substitution des isocyanates dans les polyuréthanes. Pour ce faire, trois nouvelles voies de synthèse ont été envisagées :La voie cyclocarbonate/amine est la plus novatrice. Dans un premier temps, la réactivité de cyclocarbonates et d'amines modèles a été étudiée ainsi que l'effet de différents catalyseurs. Les meilleurs catalyseurs sont de la famille des thiourées, urées et guanidines. Puis une voie d'accès à des cyclocarbonates incolores a été mise au point. Enfin, une étude a permis de mettre en évidence que les liaisons hydrogènes étaient responsables du faible avancement de la réaction lors de la synthèse de polyhydroxyuréthanes linéaires.La voie époxy/amine a permis de développer une gamme de matériaux transparents avec des Tg allant de 18 à 47°C. Une étude IR a été réalisée, permettant de mieux appréhender le phénomène de carbonatation de l'amine, récurent lors de la synthèse de résines époxys à température ambiante. L'utilisation de prépolymères aminotéléchéliques permet de contourner ce phénomène.La voie acrylate/amine a permis de développer un matériau transparent de basse Tg, -12°C. L'étude de la réactivité des acrylates avec les amines a été réalisée par DSC et RMN. Des tests de formulation ont été effectués dans le but d'augmenter la Tg / Juxta company produces thick transparent polyurethane coatings. These coatings are made from hazardous compounds, isocyanates and a mercury based catalyst. In order to protect its employees and consumers Juxta company wants to get rid of the isocyanates in its formulations. Therefore, three new synthesis pathways have been considered.The carbonate/amine pathway is the more innovative one. First, the reactivity and catalysis of model cyclocarbonates and amines were studied. The thioureas, ureas and guanidines proved to be very efficient catalyst families for the cyclocarbonate aminolysis. Then a synthesis was developed to obtain transparent cyclocarbonates. To conclude, a study conducted on linear polyurethanes demonstrated that hydrogen bondings are responsible for the low conversions observed with this reaction.Transparent materials with Tg ranging from 18°C to 47°C were synthesized using the epoxy/amine pathway. An IR study was performed to better understand the amine carbonation phenomenon. It is a frequent phenomenon when the epoxy resins are synthesized at room temperature. Aminotelechelic prepolymers can be used to circumvent it.A low Tg (-12°C) transparent material was synthesized using acrylate/amine synthesis. The couple reactivity was studied by DSC and NMR. Then several formulations were performed in order to increase the Tg
10

Synthèses originales de polyuréthanes sans isocyanate (NIPUs) / Original synthesis of Non-Isocyanate PolyUrethanes (NIPUs)

Vanbiervliet, Élise 28 September 2016 (has links)
Actuellement, les polyuréthanes (PUs) sont produits industriellement par polyaddition entre un diisocyanate et un polyol. Le caractère fortement sensibilisant des isocyanates, mettent ces composés sous forte pression réglementaire au niveau européen (REACH) et ont créé le besoin d'obtenir des PUs ne provenant pas d'isocyanates, lesquels sont plus communément appelés Non-Isocyanate PolyUréthanes (NIPUs). Les travaux de cette thèse visent ainsi à établir de nouvelles voies d'accès à des NIPUs. Des pré-polymères téléchéliques ont été synthétisés via la réaction de métathèse. Plusieurs groupements terminaux (jusqu'à 16), réagissant à température ambiante avec une amine primaire, ont été greffés avec succès à ces pré-polymères. La réaction avec plusieurs diamines a conduit à la synthèse de nouveaux matériaux NIPUs entièrement caractérisés. Les stratégies de synthèses développées au cours de ces travaux de thèse ouvrent de nouvelles perspectives quant à l'industrialisation de NIPUs. / Conventional polyurethanes (PUs) involve the use of isocyanates, which are considerably toxic and require phosgene for their manufacture. To tackle environmental issues, it is necessary to elaborate different routes to PUs. In this context, two isocyanate-free strategies towards the preparation of polythiourethanes (PTUs), i.e. non-isocyanate polyurethanes (NIPUs), have being developed. The first way involves the synthesis of α,ω-di(dithiocyclocarbonate) telechelic poly(propylene glycol) (bis(5DTCC)-PPG), poly(tetrahydrofurane diglycidyl ether) (bis(5DTCC)-PTG), upon chemical modification of the corresponding α,ω-diepoxide telechelic polymers (PPG, PTG, respectively) through cycloaddition of carbon disulfide. The second approach involves the ring-opening metathesis polymerization (ROMP), using Grubbs’ 2nd generation ruthenium catalyst, of cycloolefins using 16 differents chain-transfer agents. Bis(5DTCC) telechelic copolyolefins are thus synthesized. Reaction of the end-capping 5DTCC moieties with a diamine by ring-opening polyaddition ultimately affords at room temperature the corresponding NIPTU.

Page generated in 0.0458 seconds