La stéréolithographie biphotonique (TPS) est une technique de microfabrication 3D basée sur la polymérisation par absorption biphotonique qui permet d’obtenir en une seule étape des structures 3D complexes avec des détails sub-100nm. Aujourd’hui, en raison des conditions spécifiques de fabrication liées à la TPS (fort flux, confinement spatial de la photoréaction,…), un des enjeux concerne le développement de matériaux fonctionnels compatibles avec ce procédé. Dans ce contexte, l’objectif de cette thèse a été de développer de nouveaux matériaux fonctionnels à base de polymères à empreintes moléculaires (MIP) pour élaborer des capteurs chimiques. Une première partie de ce travail a consisté à mettre en place différentes méthodes dédiées à la caractérisation des propriétés géométriques, chimiques et mécaniques des matériaux élaborés par TPS. Par exemple, la vibrométrie laser a été utilisée pour la première fois afin de sonder de façon non-invasive les propriétés mécaniques de microstructures réalisées par TPS. Dans un second temps, ce travail a été mis à profit pour étudier l’impact du processus de fabrication (i.e. conditions photoniques) ainsi que des paramètres physico-chimiques affectant la photoréaction (i.e. inhibition par oxygène et nature du monomère) sur les propriétés finales des matériaux. Enfin, en s’appuyant sur les résultats obtenus, des microcapteurs chimiques à base de MIP, à lecture optique ou mécanique, ont été fabriqués. Leurs propriétés de reconnaissance moléculaire, ainsi que leurs sélectivités ont été démontrées pour une molécule cible modèle (D-L-Phe). / The two-photon stereolithography (TPS) technique is a micro-nanofabrication method based on photopolymerization by two-photon absorption that allows in a single manufacturing step to obtain complex 3D structures with high-resolution details (sub-100nm). Due to the specific conditions of TPS process (intense photon flux, spatial confinement of the photoreaction…) one of the main concerns today is the development of functional materials compatible with the TPS. According to the aforementioned, the general objective of this thesis was to develop new functional materials based on molecularly imprinted polymers (MIP) to elaborate chemical microsensors. In the first step of this work, different methods were implemented to characterize the geometrical, chemical and mechanical properties of the materials synthesized by TPS. For example, laser-Doppler vibrometry was used for first time to evaluate the mechanical properties of microstructures fabricated by TPS in a non-invasive way. In the second step, the characterization methodology was used to study the impact of the manufacturing process (i.e. photonic conditions) and the physicochemical parameters that affect the photoreaction (i.e. oxygen inhibition and the nature of the monomer) and the final properties of the materials. Finally, the obtained results enabled the prototyping of chemical microsensors based on MIP. Their molecular recognition properties and their selectivity were demonstrated for the molecule (D-L-Phe) by an optical and a mechanical sensing method.

No description available.

Les nanogels sont de bons candidats pour la délivrance d’actifs. Ces réseaux de polymères réticulés et de taille nanométrique, sont gonflés d’eau. Ils sont donc capables d’encapsuler une protéine à l’intérieur de leurs pores et de la libérer en fonction de l’état de gonflement du réseau. Cet état peut être modulé par la densité de réticulation du réseau ou par l’application d’un stimulus externe tel que le pH, la température ou encore une biomolécule telle que le glucose. Ainsi, les nanogels sensibles au glucose se présentent comme des candidats idéaux pour administrer l’insuline de façon asservie à la glycémie. Afin de satisfaire aux critères de biocompatibilité et de biorésorption des vecteurs, nous avons choisi de développer des nanogels à base de polysaccharide, en particulier à base d’acide hyaluronique (HA). Ceux-ci sont obtenus par réticulation du HA, préalablement modifié par des fonctions réticulables telles que les méthacrylates, dans des nanogouttes d'émulsion eau-dans-huile. Des nanogels de taille et de porosité modulables ont été synthétisés grâce à un bon contrôle 1) de la modification chimique des précurseurs par des fonctions réticulables (taux de méthacrylation), 2) de l’émulsion matricielle (taille, stabilité), 3) des conditions de réticulation par photopolymérisation gouvernant le taux de conversion des méthacrylates. Ce savoir-faire a ensuite été appliqué à la synthèse de nanogels modifiés par des dérivés de l’acide phénylboronique, ligand du glucose, afin d’obtenir des matériaux dont le taux de gonflement varie en fonction de la glycémie. L’intérêt applicatif de ces objets a été évalué vis-à-vis des propriétés d’encapsulation de l’insuline, de dégradabilité enzymatique, et de biocompatibilité. / Nanogels are an attractive class of delivery systems. These soft particles, made of highly swollen polymer network, can physically entrap a drug and release it at a rate depending on its diffusion though the network. Therefore, any change in the swelling degree can trigger the release kinetics. This parameter can be tuned by modifying the density of cross-links in the gel matrix or by changing the environmental conditions such as pH, temperature or analyte such as glucose. Thus, glucose-responsive nanogels are good candidates to be used as self-regulated systems for insulin delivery. To fulfill both biocompatibility and biodegradability criteria, our attention has been focused on the design of new nanogels made of polysaccharides, in particular made of hyaluronic acid (HA), as a main constituent. HA was at first covalently modified with polymerizable methacrylate functions and confined in nanoreactors during photopolymerization using water-in-oil miniemulsions as template. Biodegradable nanogels with a well-defined size and various cross-linking degrees were thus achieved, thanks to a good control of 1) the chemical modification of HA with methacrylates (degree of methacrylation) 2) the emulsion template (size, stability), 3) the photopolymerization conditions which governed the conversion rate of the polymerization. Further modification of the polysaccharide with phenylboronic acid as a glucose-sensitive group yielded nanogels whose swelling behavior could vary as a function of glucose concentration. These systems were further studied as insulin delivery systems. Moreover, their biodegradability, stability and biocompatibility were assessed.

Nesta tese, estudamos o processo de absorção multifotônica em polímeros e resinas poliméricas, abordando tanto aspectos fundamentais quanto aplicados. Com relação aos aspectos fundamentais, estudamos processos de absorção multifotônica (absorção de dois, três e quatro fótons) no polímero conjugado MEH-PPV (poly(2-methoxy-5-(2´-ethylhexyloxy)-1,4- phenylenevinylene)), utilizando a técnica de Varredura-Z com pulsos ultracurtos. Através desta técnica, determinamos o espectro da absorção de dois, três e quatro fótons do MEHPPV. As seções de choque de absorção de multi-fótons correspondentes a cada processo foram determinadas através do ajuste das curvas experimentais com um conjunto de equações desenvolvidas neste trabalho. Os resultados obtidos permitiram traçar relações entre os espectros não lineares e os níveis de energia do polímero. Na vertente mais aplicada do projeto, estudamos a fotopolimerização de resinas acrílicas através do processo de absorção de dois fótons. Devido ao confinamento espacial da polimerização, graças à absorção de dois fótons, este método permite a confecção de micro-estruturas complexas para diversas aplicações tecnológicas. Além da fabricação de microestruturas convencionais não dopadas, neste trabalho desenvolvemos uma metodologia que possibilita a fabricação de microestruturas dopadas com MEH-PPV, visando a produção de micro-elementos fluorescentes para dispositivos fotônicos, e microestruturas dopadas com quitosana, um polímero biocompatível que pode ser utilizado em aplicações médicas e biológicas. / In this thesis we have studied the multi-photon absorption process in polymers and polymeric resins, exploiting its fundamental as well as technological aspects. Regarding the fundamental aspects, we have studied the multi-photon absorption (two-, three- and four-photon absorption) in the conjugated polymer MEH-PPV (poly(2-methoxy-5-(2´-ethylhexyloxy)-1,4-phenylenevinylene)), by using the Z-scan technique with ultrashort laser pulses. Through this technique, we determined the two-, three- and four-photon absorption spectra of MEH-PPV. The multi-photon absorption cross-sections, corresponding to each specific process, have been determined by fitting the experimental data with a set of equations developed in this work. The results allowed us to correlate the nonlinear absorption spectra to the energy level of the polymer. On the technological side of this thesis, we have investigated the photopolymerization of acrylic resins by two-photon absorption. Because of the spatial confinement of the polymerization, resulting from the two-photon excitation, this method allows the fabrication of complex microstructures which can be used for several technological applications. In addition to the fabrication of undoped microstructures, in this work we have developed a methodology that allows the fabrication of microstructures doped with MEHPPV, aiming the production of fluorescent micro-elements for photonics applications, and microstructures doped with chitosan, a biocompatible polymer, that can be used for medical and biological applications.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-27T12:33:46Z No. of bitstreams: 1 fernandoantoniosimasvaz.pdf: 40063052 bytes, checksum: f272ddc4d930b7d243c50223436e02b2 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-13T13:00:49Z (GMT) No. of bitstreams: 1 fernandoantoniosimasvaz.pdf: 40063052 bytes, checksum: f272ddc4d930b7d243c50223436e02b2 (MD5) / Made available in DSpace on 2017-05-13T13:00:49Z (GMT). No. of bitstreams: 1 fernandoantoniosimasvaz.pdf: 40063052 bytes, checksum: f272ddc4d930b7d243c50223436e02b2 (MD5) Previous issue date: 2011-07-22 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / Nesta tese é descrita a preparação de novas fases estacionárias monolíticas (FEM) polimerizadas por fotoiniciação, através do método sol-gel, em capilares de sílica fundida revestidos com poliacrilato, para aplicação em eletrocromatografia capilar (ECC). Dentre as principais técnicas de separação em Química Analítica, a ECC tem despertado grande interesse no meio acadêmico, pelo fato desta combinar as vantagens tanto da cromatografia a líquido de alta eficiência quanto da eletroforese capilar. Grande parte do desenvolvimento da ECC se deve ao uso das FEM, as quais são semelhantemente aplicadas em outras técnicas cromatográficas. Ao contrário do revestimento de poliimida, amplamente empregado, o revestimento de poliacrilato, transparente acima de 370 nm e à luz visível, facilita a visualização da solução de sol no interior do capilar, o que permite controlar a injeção desta e de outras soluções, bem como observar a formação in situ da FEM. Além disso, é possível que seja feita a polimerização fotoiniciada sem a necessidade de remoção do revestimento polimérico que protege a coluna. O objetivo central deste trabalho foi entender e aprimorar o processo de fabricação das FEM para aplicações em ECC. Para isso, foram feitas modificações da câmara fotorreatora homemade utilizada para a polimerização das FEM, como uma correção na faixa espectral de trabalho de 350 a 700 nm para 350 a 400 nm; e instalação de dispositivos de segurança tanto para o operador quanto para o sistema elétrico. Para que fosse alcançado um melhor controle de injeção de fases líquidas no interior de tubos com dimensões capilares, a construção de um dispositivo de alta pressurização (DAP) que forneceu, além da pressão, grande precisão foi indispensável. O DAP, além de simples, teve ótima relação custo-benefício, comparado a modelos comerciais. O preparo das FEM foi otimizado mediante auxílio de planejamento fatorial fracionário 24-1, onde se buscou analisar propriedades eletrocromatográficas frente diferentes proporções dos reagentes empregados e tempo de incidência de luz ultravioleta (UV). Este último fator não apresentou significância e foi desconsiderado, de forma que o planejamento fosse devidamente reduzido para um planejamento fatorial completo 23, o que possibilitou uma análise mais apurada dos efeitos significativos. O fator mais influente foi a proporção de porogênio (tolueno), sendo que a melhor condição obtida foi utilizando 80,0 % (v/v) de solução porogênica; 3,5 % (m/m) de fotoiniciador óxido de bis(2,4,6-trimetilbenzoil)-fenilfosfino (Irgacure 819); razão molar água/ metacriloxipropiltrimetoxisilano (MPTMS) igual a 4 e tempo de incidência de luz UV de 10 minutos. As características morfológicas, espectroscópicas e porosidade foram avaliadas através de microscopia eletrônica de varredura, infravermelho e porosimetria por adsorção de nitrogênio, respectivamente. As FEM foram testadas em ECC pela separação de hidrocarbonetos policíclicos aromáticos (naftaleno, acenafteno, fluoreno, fenantreno e antraceno) e alquilbenzenos (etilbenzeno, propilbenzeno, butilbenzeno e hexilbenzeno), todos compostos eletricamente neutros, diluídos em metanol (1 mmol L-1 cada), utilizando tiouréia como marcador de fluxo. Como fase móvel foi utilizada a mistura de acetato de amônio 16,7 mmol L-1 pH 7,0 (60 %) e acetonitrila (40 %). A voltagem aplicada foi -20 kV; a temperatura de análise foi 20 ºC; a injeção dos analitos foi -25 mbar por 5 s; e a detecção no UV foram nos comprimentos de onda de 220 nm e 250 nm. Foi utilizado o modo ECC-rápida, que consiste na inversão do sentido de análise e injeção de padrões pela extremidade curta do capilar. Este modo se mostrou muito mais rápido, repetitivo e eficiente do que o modo normal, fornecendo em pouco mais de 12 minutos de análise, mais de 51400 pratos/m de coluna e desvios padrão relativos em tempo de migração/retenção entre 0,09 e 3,3 % e em área de pico relativa entre 0,14 e 1,6 %. Os perfis de separação em ECC corroboraram com os resultados de porosidade e morfologia obtidos. / This thesis describes the preparation of new monolithic stationary phases (MSP) polymerized by photoinitiation through sol-gel approach in polyacrylate-coated fused silica capillary, for application in capillary electrochromatography (CEC). CEC has been concentrated much attention among the major separation techniques in analytical chemistry because it combines the advantages of both high performance liquid chromatography and capillary electrophoresis. Much of the CEC development is due to the use of MSP, which are similarly applied to other chromatographic techniques. Unlike polyimide-coating, widely used, the polyacrylate-coating, which is transparent above 370 nm and visible, enables the visualization of the sol solution within the capillary, allowing one to control the injection of sol and other solutions, in addition to observe the in situ formation of the MSP. Furthermore, it is possible to perform the photoinitiated polymerization without removing this polymeric coating that protects the capillary. The main purpose of this work was to comprehend and improve the fabrication process of MSP, for CEC applications. For this, some changes were set in the homemade photo reactor chamber, used for the MSP polymerization, like correction in the work range from 350 – 700 nm to 350 – 400 nm; and installation of security devices for both operator and electric system safeties. For better control of liquid phases injection within tubes with capillary dimensions, the build of a high-pressure device (HPD) that provides a great precision, in addition to the high-pressure, was essential. HPD is simpler and relatively cheaper when compared to commercial models. The preparation of the MSP has been optimized through assistance of a 24-1 fractional factorial design, with the intention to investigate electrochromatographic properties with different amounts of employed reagents and ultraviolet (UV) light incidence time. The later factor did not show significance and was unconsidered, making the design possible to be reduced to a 23 complete factorial design, which allowed analyzing the significant effects accurately. The most influent factor was the porogen (toluene) proportion, and the best condition was obtained using 80.0 % (v/v) of porogenic solution; 3.5 % of photoinitiator bis(2,4,6 trimetylbenzoyl)-phenylphosphine oxide (Irgacure 819); water to metacryloxypropyltrimethoxysilane (MPTMS) molar ratio equal to 4 and 10 minutes of UV light incidence time. The MSP morphological, spectroscopic characteristics and porosity were evaluated through scanning electron microscopy, infrared spectroscopy and nitrogen adsorption porosimetry, respectively. The MSP has been tested in CEC through the separation of polycyclic aromatic hydrocarbons (naphthalene, acenaphthene, fluorene, phenanthrene and anthracene) and alkylbenzenes (ethylbenzene, propylbenzene, butylbenzene and hexylbenzene), which are electrically neutral compounds, after dilution in methanol (1 mmol L-1 each), using thiourea as the flow marker. As mobile phase a mixture of ammonium acetate 16.7 mmol L-1 at pH 7.0 (60.0 %) and acetonitrile (40.0 %) was used. The applied voltage was -20 kV, the temperature of analysis was 20 °C, the analyte injection was -25 mbar for 5 s, and UV detection was done at 220 and 250 nm. A fast-CEC mode, which consists to reverse the analysis direction and to introduce the analyte by capillary short-end injection, was performed. This mode was much more fast, repetitive and efficient than the normal one, providing in a little more than 12 minutes over than 51400 plates per meter of column and relative standard deviations ranging from 0.09 to 3.3 % for migration/retention time and from 0.14 to 1.6 % for relative peak area. The separation profiles in CEC corroborate with the porosity and morphology results.

Le travail de thèse porte sur la synthèse de nouveaux monomères photopolymérisables issus de la biomasse, l’étude de leur photopolymérisation et la caractérisation des matériaux qui en résultent. Les monomères formulés ont été testés dans un procédé d’impression de caractères Braille.Les monomères ont été élaborés en deux étapes en utilisant un chemin réactionnel simple, économique et respectueux de l’environnement. La première étape a consisté à faire réagir des dérivés du glycérol (carbonate de glycérol ou glycidol) avec des acides gras. Dans un deuxième temps, les [alpha]-monoglycérides obtenus ont été fonctionnalisés en vue de les rendre photopolymérisables. Les différents monomères obtenus porteurs de fonctions (méth)acrylate et/ou époxy ont été photopolymérisés en quelques secondes en présence d’un photoamorceur. Les cinétiques de photopolymérisation ont été suivies par spectrométrie IR-TF en mode ATR et différents paramètres tels que la quantité et la nature du photoamorceur, l’intensité d’irradiation et la température ont été optimisés. Les différents matériaux obtenus après photoréticulation ont été caractérisés afin de mettre en évidence leurs principales physico-chimiques. Des relations structure – propriétés ont ainsi été établies.Enfin, une formulation photopolymérisable présentant une viscosité compatible avec le procédé d’impression Braille a été élaborée par ajout de silice nanométrique. Les points Braille obtenus présentent des caractéristiques proches de ceux réalisés par le partenaire industriel. / The work of the PhD deals with the synthesis of polymerizable monomers derived from biomass, the study of their photopolymerization and the characterization of the resulting materials. The formulated monomers were tested in a printing method of Braille characters.The monomers were prepared in a two-steps reaction that is simple, economic and environmentally friendly. The first step comprised a reaction between glycerol derivatives (glycerol carbonate or glycidol) and fatty acids. In the second step, the obtained [alpha]-monoglycerides were functionalized to obtain photopolymerizable monomers. The different obtained monomers that bear (meth)acrylate and/or epoxy groups were photopolymerized in a few seconds in the presence of photoinitiator.The photopolymerization kinetics were followed by FT-IR spectroscopy in ATR mode, and various parameters such as the amount and the nature of the photoinitiator, the irradiation intensity and the temperature were optimized. The different photocured materials were characterized to highlight their main physicochemical properties. Structure-properties relations were then established.Finally, a photopolymerizable formulation having a viscosity compatible with the printing process of Braille characters was developed by adding nanometric silice. The obtained Braille characters exhibited features close those carried out by the industrial partner.

Inscrite dans le cadre d’un projet ANR, la thèse porte sur l’étude et le développement des revêtements poudres UV en vue du recouvrement de panneaux de bois. La thèse détaille les spécificités de ces formulations et de la technologie associée afin de constituer une bibliographie solide propre à ce domaine. Les travaux expérimentaux se basent sur des formulations modèles comprenant une résine poudre UV (uréthane diacrylate ou polyester diméthacrylate) et un photoamorceur. Une étude mécanistique permet de montrer les influences de la température et de la viscosité, de l’intensité lumineuse et de l’atmosphère sur la réactivité des formulations modèles. Il est également démontré que les mécanismes de terminaison spécifiques à ces systèmes suivent des processus mixtes: bimoléculaire, pseudo-monomoléculaire et recombinaison des radicaux primaires. La prédominance des différents processus dépend de l’avancement de la réaction. La formation du réseau de réticulation est ensuite étudiée en fonction de la source d’irradiation: convoyeur semi-industriel doté de lampes UV ou système LED émettant autour de 395 nm. Les caractéristiques du réseau de réticulation (Tg, densité de réticulation, module d’Young) sont reliées aux propriétés des revêtements finaux (flexibilité, résistance à la rayure ou au solvant). L’utilisation d’acrylates multifonctionnels a un impact sur les longueurs de chaînes et la densité de réticulation. En vue d’applications spécifiques, il est finalement proposé d’incorporer une argile modifiée avec de l’Argent au sein des formulations modèles pour obtenir des revêtements poudres UV antibactériens homogènes possédant de bonnes propriétés de résistance. / In the frame of a project of the Agency National Research (France), the thesis deals with the study and the development of UV powder coatings dedicated to wood based panels. The work describes the main features of these formulations and the associated technology in order to offer a strong bibliography specific to this area. The experiments are based on model formulations containing an UV powder resin (diacrylate urethane or dimethacrylate polyester) and a photoinitiator. A mechanistic study allows highlighting the influence of temperature and viscosity, light intensity and atmosphere on the reactivity of the model formulations. It is also shown that the termination mechanisms specific to theses systems follow mixed processes: bimolecular, pseudo-monomolecular and primary radical termination. The predominance of the different processes is related to the reaction conversion. The building of the crosslinking network is then studied depending of the irradiation source: semi-industrial conveyor equipped with UV lamps or LED system emitting around 395 nm. The characteristics of the crosslinking network (Tg, crosslinking density, Young’s modulus) are linked to the final coatings properties (flexibility, scratch and solvent resistance). The incorporation of multifunctional acrylates affects the chains length and crosslinking density. To reach specific applications, it is finally proposed to add a silver-modified clay into model formulations to obtain homogeneous antibacterial UV powder coatings exhibiting good resistance properties.

L’objectif de ces travaux a été de développer des vernis acrylate photo-polymérisables à 100% d’extrait sec, destinés à protéger des pièces thermoplastiques en polycarbonate contre les endommagements mécaniques, en particulier contre la rayure. Les relations entre la composition, la structure et les propriétés de ces revêtements ont été explorées. Pour ce faire ont été étudiées la morphologie, les propriétés thermomécaniques ainsi que la résistance à la rayure des matériaux. Cette dernière a été évaluée par des tests de micro-scratch. La cinétique de formation des réseaux polymères a elle aussi été étudiée, par photo-DSC. Tous les matériaux étudiés présentent, en analyse thermomécanique dynamique, un module élevé à l’état caoutchoutique ainsi qu’une large relaxation mécanique. Un vernis pétro-sourcé à 100% d’extrait sec, qualifié de standard, a servi de point de départ à ces travaux. Il a tout d’abord été comparé à un vernis commercial solvanté photo-polymérisable, spécialement conçu pour la protection de pièces thermoplastiques. Celui-ci s’est avéré être plus efficace en termes de résistance à la rayure. Dans un deuxième temps, a été étudiée l’influence sur les propriétés du vernis standard pétro-sourcé d’un monomère multicyclique entrant dans sa composition. La modification de son pourcentage n’a permis d’apporter aucun bénéfice en termes de résistance à la rayure. Des nanoparticules de silice, d’alumine ou de zircone, disponibles sous forme de dispersion dans un monomère acrylate, ont ensuite été incorporées dans le vernis standard pétro-sourcé. Une organisation particulière de la nano-silice et de la nano-alumine au sein des matériaux étudiés a pu être observée par microscopie électronique en transmission. Il a été constaté que le taux de charge doit être élevé pour observer une augmentation du module élastique et une amélioration de la résistance à la rayure du vernis (≥15% massique dans le cas de la nano-silice). Par ailleurs, l’ajout de 5% massique de nano-silice dans le vernis n’a conduit à aucune modification de sa cinétique de photo-polymérisation. Enfin, une partie des composés acrylate pétro-sourcés du vernis standard a été substituée par des acrylates bio-sourcés disponibles industriellement. La cinétique de photo-polymérisation des deux types de vernis est similaire. Les conclusions de la comparaison entre les vernis bio-sourcés et le vernis standard pétro-sourcé en termes de résistance à la rayure dépendent de l’épaisseur des revêtements étudiés. L’ajout d’un composé monoacrylate bio-sourcé à la formulation des vernis tend à améliorer la recouvrance élastique des revêtements de faible épaisseur. L’acrylate d’isobornyle est en particulier intéressant, car il a aussi tendance à retarder l’apparition des craquelures au cours de la rayure. / The aim of this work was to develop 100% solids photo-polymerizable acrylate coatings, intended to protect thermoplastic pieces made of polycarbonate against mechanical damage, in particular scratches. The relationships between the composition, the structure and the properties of these coatings were examined. For this purpose the morphology, the thermomechanical properties and the scratch resistance of the materials, assessed by micro-scratch tests, were studied. The kinetics of the polymer network formation was also studied by photo-DSC experiments. All the materials feature a high elastic modulus and a broad mechanical relaxation in dynamic thermomechanical analysis. A 100% solids petro-based coating (standard) constituted the starting point of this work. First it was compared to a commercial photo-polymerizable coating containing solvents, specially designed to protect thermoplastic pieces. This commercial coating turned out to be more efficient against scratches. In a second time was studied the influence of the percentage of a multicyclic monomer, taking part in the composition of the standard petro-based coating, on the properties of the latter. The modification of its proportion does not bring any advantage concerning the scratch resistance. Silica, alumina and zirconia nanoparticles, dispersed in an acrylate monomer, were then incorporated in the standard petro-based coating. A particular organization of the silica or alumina nanoparticles in the materials could be observed by transmission electron microscopy. A high filler content is required to observe an increase in the elastic modulus and an enhancement of the scratch resistance of the coating (≥15% by weight for the nano-silica). Moreover, no change of the photo-polymerization kinetics was noticed through the addition of 5% by weight of nano-silica in the coating. Finally, some of the petro-based acrylate compounds of the standard coating were substituted by commercially available bio-based acrylate monomers. Both types of coatings feature similar polymerization kinetics. The conclusions concerning the comparison of the scratch resistance of the bio-based and standard petro-based coatings depend on their thickness. The incorporation of a bio-based monoacrylate compound in low thickness coatings tends to improve the elastic recovery. Isobornyl acrylate is particularly interesting since it also tends to delay the apparition of cracks along the scratch.

Le travail présenté porte sur l’étude de la résistance à la rayure d’un vernis acrylate liquide à 100% d’extrait sec et photo-réticulable, en fonction des conditions de réticulation et d’application. Ce vernis est destiné à être appliqué sur des substrats thermoplastiques. Une première étude réalisée sur support polycarbonate a permis de mettre en évidence l’interaction entre le supporte et les monomères du vernis. La photo-polymérisation nécessite une source de rayonnement UV afin de former le réseau 3D. L’évolution de l’énergie (dose UV) et de la puissance (pic d’irradiance UV) a été décrite en fonction des différents paramètres de réglages (vitesse de défilement et position de l’échantillon sous la lampe, distance entre ces deux derniers, focalisation du rayonnement,). La résistance à la rayure des revêtements a été caractérisée par le test de microscratch qui permet de mettre en évidence la transition ductile/fragile, ainsi que le comportement élastique du système feuil/substrat et donne une information sur le travail d’adhésion, selon le mode de rupture. Ces analyses ont été complétées par la mesure du taux de conversion. Le réglage du rayonnement UV permet de modifier les propriétés finales du revêtement. Il existe également un lien entre l’angle d’incidence du rayonnement, l’épaisseur de vernis, et un préchauffage des matériaux avant l’application ou la réticulation, sur le taux de conversion et la résistance mécanique du film. La rhéologie du vernis, en vue d’une application au bol rotatif avec effet électrostatique, a été étudiée. Nous avons montré l’influence du chauffage du vernis sur la viscosité. Les essais en conditions semi-industrielles ont permis de mettre en évidence les paramètres procédés impactant l’aspect et le tendu de la pièce. / This research aimed to study the impact of the application and the curing process conditions on the UV-cured coating properties. The UV formulation is a high solid content clear-coat, containing acrylates oligomer and monomers, and developed for thermoplastics substrate, to protect them against scratches. The characterization of the coating and the polycarbonate substrate showed the interaction between the two polymers. UV irradiation is the key to create the polymer network. Several parameters can affect the evolution of its energy and intensity: the conveyor speed, the position of the sample under the bulb, the distance between the last two, and the focalisation of the UV rays. The coating is then analysed in terms of scratch resistance, by the microscratch test. This test gives information about the ductile/brittle transition, the elastic behaviour and the adhesion work. It is completed by the reticulation rate measure. These properties can be modified by the UV radiation setting and the process conditions, like the angle of the support, the coating thickness, and the thermic pre-treatment of the materials before the application or the curing. The clear coat is aimed to be sprayed by electrostatic rotary deposition. The study of the rheological behaviour of the liquid coating showed an impact of the heating on its viscosity. Semi-industrials tests allowed highlighting the process parameters in order to improve the coating levelling and appearance.