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Interest in macrocyclic monomers can be dated back to the 1960's. The recent surge of research activities in this area is prompted by two facts: the encouraging discovery of high yield synthesis and facile ring-opening polymerization of cyclic polycarbonate; the need for a technique to solve the tough processibility problem of high performance polymers. This work was intended to address the following aspects in the cyclic poly(ether ketone) or sulfone system. The first goal was to understand the structure-property relationship of this type of macrocycles. A large number of macrocycles were synthesized by nucleophilic aromatic substitution cyclization reactions under pseudo-high dilution conditions. Pure individual macrocycles as well as cyclic mixtures were characterized by NMR, HPLC, GPC, FABMS, MALDI-TOF-MS, DSC and TGA. Comparison study suggests that the cyclic distribution is kinetically controlled. Several factors determine the melting points of individual macrocycles. The first factor is the ring size. A series of cyclic monomers for poly(ether ether ketone)s were synthesized and isolated. The melting point decreases as ring size increases. Single crystal X-ray structural results suggest that this phenomenon is related to the increased flexibility of the larger sized macrocycles. The second factor is the functional groups of the macrocycles. X-ray structural and GPC experiments reveal that the sulfone group is more rigid than the ketone group, than ether group. The effect of functional groups on melting point is in the order sulfone>ketone>ether. A third factor is the symmetry of the macrocycles. Breaking the symmetry of macrocycle through comacrocyclization dramatically decreases the melting point of individual macrocycles as well as the cyclic mixture as a whole. Based on these findings, a novel two step method was developed to control the ring size distribution, which effectively reduced the amount of the small sized macrocycle and decreased the melting point. In addition to the nucleophilic aromatic substitution cyclization, it was also demonstrated in this work that macrocycles can be synthesized by Friedel-Crafts acylation cyclization. However, this method is limited by the solubility problem. The ring-opening polymerization of macrocyclic monomers was systematically studied. Several factors were considered in this study: the nature and amount of catalyst, temperature and time. CsF; metallic phenolate and Na2S are good initiators. Conversion to near 100 % is possible under the controlled polymerization conditions. It was found that crosslinking is an inherent phenomenon. The molecular weight of the soluble fraction near complete conversion is almost independent of initiator and polymerization temperature. It is limited by the crosslinking reaction. It is demonstrated for the first time that the macrocyclic monomer techniques can be applied to more valuable semicrystalline systems. Tough polymers such as high performance poly(ether ether ketone)s were produced through ring-opening polymerization. The last chapter is devoted to the challenging synthesis of monodisperse poly(ether ether ketone)s. A convergent strategy was devised. A monofluoroaryl compound was synthesized by Friedel-crafts acylation reaction. The final monodisperse linear oligomers were generated by reacting the monofunctional compound with a bisphenol through a quantitative reaction. / Ph. D.

Les matériaux composites à matrices thermoplastiques renforcées de fibres longues sont étudiés de manière intensive pour leur introduction dans les prochaines générations de pièces structurales aéronautiques. Par ses performances thermomécaniques, l’unidirectionnel carbone/PEEK apparait comme un candidat possible, toutefois les procédés actuels de formage ne semblent pas en mesure de réaliser des pièces épaisses avec ce matériau. Ce travail de thèse a pour objectif de proposer un procédé innovant capable de réaliser des pièces composites carbone/PEEK épaisses de types cornières structurales en L ou en U. Le cœur du concept est la réalisation de l’étape de mise en forme dans le domaine caoutchoutique pour favoriser le glissement inter-plis et éviter ainsi la formation de défaut de type plissement quelle que soit l’épaisseur. Dans un premier temps, la fenêtre de processabilité adaptée à l’obtention d’une préforme a été définie en se basant sur les propriétés physiques de la matrice PEEK. La mise en application du procédé proposé, faite à partir des résultats collectés, a mis en évidence la complexité des mécanismes de déformation dans ces conditions spécifiques. Une meilleure compréhension de ces mécanismes a pu être apportée par une approche de modélisation et de simulation. Enfin, la santé matière et les performances des pièces réalisées par ce nouveau procédé ont été mesurées, la comparaison à des pièces obtenues par un procédé conventionnel de formage valide le procédé proposé. / Thermoplastic composite materials based on long carbon fibers are extensively studied to prepare their introduction in the next generation of structural parts in aerospace industry. Because of its thermomechanical properties, unidirectional carbon/PEEK appears as a potential candidate, however the current forming processes do not appear able to manufacture thick parts with this material. The aim of my PhD thesis is to propose an innovative process to produce thick carbon/PEEK parts of L-shape and U-shape profiles. The heart of the concept is to carry out the step of deformation when the matrix is in the rubbery state to promote inter-ply sliding and thus avoiding the formation of wrinkling defect whatever the thickness. In a first step, the processing window suitable to obtain a preform was defined based on the physical properties of the PEEK matrix. The implementation of the proposed method, based on the results collected, has highlighted the complexity of the deformation mechanisms under these specific conditions. A better understanding of these mechanisms has been provided by a modeling and simulation approach. Finally, the material properties and the performance of the parts produced by this new process have been measured, the comparison with parts obtained by a conventional forming process validates the proposed process.

Atualmente a área de saúde vem buscando auxílio na engenharia para a contribuição no estudo e confecção de próteses para casos específicos de fraturas ou doenças ósseas. Com o avanço da tecnologia surgiram processos de manufatura que tornam possível a fabricação de próteses personalizadas. Uma dessas tecnologias é a manufatura aditiva. O grande desafio no momento está na fabricação de próteses por manufatura aditiva que combinem desempenho biomecânico e resistência estrutural. Nesse contexto, o objetivo deste trabalho é desenvolver elementos de fixação, especificamente âncoras de sutura de polímeros PEEK e PEKK, considerando seus requisitos estruturais através de simulações pelo método dos elementos finitos, e considerando que sejam fabricadas através de processos de manufatura aditiva. Este desenvolvimento permitirá a substituição de âncoras de sutura de liga de titânio, hoje largamente empregadas pelos cirurgiões, por âncoras de sutura de polímeros biocompatíveis, o que possibilitará que estes polímeros sejam absorvidos pelo corpo humano em curto e médio prazo, permitindo a completa restituição do osso afetado, melhorando a qualidade de vida do paciente pós-cirurgia. Os resultados obtidos neste trabalho indicam que a técnica poderá resultar em próteses com a biocompatibilidade desejada e resistência mecânica adequada. Próteses permanentes (articulações) ou provisórias (âncoras de sutura) seriam um dos critérios para a escolha do material a ser utilizado, absorvível ou não pelo corpo humano. / Nowadays medicine is searching assistance from engineering that may contribute in studies and confection of prothesis to specific cases of fractures and bone diseases. With the advance of technology new processes of manufacture were risen, making possible the confection of personalized prothesis. The biggest challenge of the moment is in the manufacture of additive prothesis that can combine biomechanics performance and structural resistance. In this context, the objective of this dissertation is to develop PEEK and PEKK polymer suture anchors, considering its structural requirements, taking into account their mechanical strength, through simulation by the finite element method, and considering additive manufacturing processes. This development will allow the replacement of titanium alloy suture anchors, now widely used by surgeons by suture anchors of biocompatible polymers, which enable these polymers to be absorbed by the human body in the short and medium term, allowing full regeneration of affected bone, improving the quality of life of the patient. The results of this study indicate that the technique could result in prosthesis with the desired biocompatibility and adequate mechanical strength. Permanent prosthesis (joints) or temporary (suture anchors) would be one of the criteria for the choice of material to be used, absorbable or non absorbable by the human body.

As características tribológicas do poli-éter-éter-cetona (PEEK) contendo de 0% a 40% de fibra de carbono, sob deslizamento em ambiente lubrificado com óleo, foram estudadas para diferentes acabamentos superficiais da contrapeça. Os quatro acabamentos escolhidos, comumente usados na indústria automobilística, foram o torneamento, a retífica, o brunimento e o polimento. O sistema de teste usado foi o tri-pino-disco, com o pino em PEEK e a contrapeça em aço, sendo totalmente imersos no óleo ATF Dexron VI. Alguns parâmetros de teste foram mantidos constantes como a pressão aparente de 2 MPa, a velocidade linear de deslizamento de 2 m/s e a temperatura do óleo em 85°C. Analisou-se o efeito do tempo de deslizamento na taxa de desgaste e no atrito para o PEEK com 30% de fibra de carbono contra disco acabado por torneamento, estudou-se o efeito do acabamento do disco no atrito e desgaste do PEEK natural e do PEEK com 30% de fibra de carbono, avaliou-se o efeito da adição da fibra de carbono na taxa de desgaste e atrito em acabamento torneado e foi definido o regime de lubrificação para os acabamentos de polimento e torneamento para o PEEK natural e para os acabamentos de polimento, brunimento, retífica e torneamento para o PEEK com 30% de fibra de carbono nas condições de 2 MPa e 2 m/s. Constatou-se que o regime permanente de desgaste ocorreu a partir de 60 minutos após a estabilização da taxa de desgaste e coeficiente de atrito. O atrito e o desgaste do PEEK e seus compósitos se mostraram sensíveis ao acabamento da contrapeça, pois este foi o principal fator que definiu os regimes de lubrificação. Nas condições de teste supracitadas o polimento operou em regime hidrodinâmico, o torneamento e a retífica em regime limítrofe, e o brunimento em regime misto. Foi levantada a curva de Stribeck para o PEEK com 30% de fibra de carbono deslizando contra o disco com acabamento de brunimento para a faixa de pressão de 1 MPa a 14 MPa. Nestas condições foram observados os três principais regimes de lubrificação, tornando possível gerar um mapa que relaciona o regime de lubrificação com pressão, velocidade e coeficiente de atrito. / The sliding tribological properties of poly-ether-ether-ketone (PEEK) containing from 0 to 40% of carbon fiber were studied within oil lubricated environment for different surface finishing of the counterpart. Four different finishing processes commonly used in the automotive industry were chosen for this study: turning, grinding, honing and polishing. The test system used was three pin-on-disc with pins made of PEEK and counterpart made of steel, they were fully immersed in the Dexron VI ATF oil. Some test parameters were held constant as the apparent pressure of 2 MPa, the linear velocity of 2 m/s and the oil temperature at 85 °C. It was analyzed the effect of the sliding time on friction and wear of PEEK with 30% of carbon fiber on turning disk, studied the effect of disc finishing on friction and wear of natural PEEK and PEEK with 30% of carbon fiber, evaluated the effect of carbon fiber on wear rate and friction for turning counterbody finishing and the lubrication regime was for polishing and turning finishes for natural PEEK and polishing, honing, grinding and turning for PEEK with 30% of carbon fiber under 2 MPa and 2 m/s. It was found that steady state of wear occurred from 60 minutes of test after wear rate and friction coefficient stabilization. The friction and wear of PEEK and its composites were sensitive to the counterbody finishing; it was the main factor which defined the lubrication regimes. In the above test conditions polishing operated in hydrodynamic regime, turning and grinding on boundary condition and honing in mixed regime. The Stribeck curve was raised for PEEK with 30% carbon fiber by sliding against the honing finishing disk under 1 MPa to 14 MPa of apparent pressure range. Under these conditions the three main lubrication regimes were observed and it was possible to create a map that relates lubrication regime with pressure, speed and coefficient of friction.

As características tribológicas do poli-éter-éter-cetona (PEEK) contendo de 0% a 40% de fibra de carbono, sob deslizamento em ambiente lubrificado com óleo, foram estudadas para diferentes acabamentos superficiais da contrapeça. Os quatro acabamentos escolhidos, comumente usados na indústria automobilística, foram o torneamento, a retífica, o brunimento e o polimento. O sistema de teste usado foi o tri-pino-disco, com o pino em PEEK e a contrapeça em aço, sendo totalmente imersos no óleo ATF Dexron VI. Alguns parâmetros de teste foram mantidos constantes como a pressão aparente de 2 MPa, a velocidade linear de deslizamento de 2 m/s e a temperatura do óleo em 85°C. Analisou-se o efeito do tempo de deslizamento na taxa de desgaste e no atrito para o PEEK com 30% de fibra de carbono contra disco acabado por torneamento, estudou-se o efeito do acabamento do disco no atrito e desgaste do PEEK natural e do PEEK com 30% de fibra de carbono, avaliou-se o efeito da adição da fibra de carbono na taxa de desgaste e atrito em acabamento torneado e foi definido o regime de lubrificação para os acabamentos de polimento e torneamento para o PEEK natural e para os acabamentos de polimento, brunimento, retífica e torneamento para o PEEK com 30% de fibra de carbono nas condições de 2 MPa e 2 m/s. Constatou-se que o regime permanente de desgaste ocorreu a partir de 60 minutos após a estabilização da taxa de desgaste e coeficiente de atrito. O atrito e o desgaste do PEEK e seus compósitos se mostraram sensíveis ao acabamento da contrapeça, pois este foi o principal fator que definiu os regimes de lubrificação. Nas condições de teste supracitadas o polimento operou em regime hidrodinâmico, o torneamento e a retífica em regime limítrofe, e o brunimento em regime misto. Foi levantada a curva de Stribeck para o PEEK com 30% de fibra de carbono deslizando contra o disco com acabamento de brunimento para a faixa de pressão de 1 MPa a 14 MPa. Nestas condições foram observados os três principais regimes de lubrificação, tornando possível gerar um mapa que relaciona o regime de lubrificação com pressão, velocidade e coeficiente de atrito. / The sliding tribological properties of poly-ether-ether-ketone (PEEK) containing from 0 to 40% of carbon fiber were studied within oil lubricated environment for different surface finishing of the counterpart. Four different finishing processes commonly used in the automotive industry were chosen for this study: turning, grinding, honing and polishing. The test system used was three pin-on-disc with pins made of PEEK and counterpart made of steel, they were fully immersed in the Dexron VI ATF oil. Some test parameters were held constant as the apparent pressure of 2 MPa, the linear velocity of 2 m/s and the oil temperature at 85 °C. It was analyzed the effect of the sliding time on friction and wear of PEEK with 30% of carbon fiber on turning disk, studied the effect of disc finishing on friction and wear of natural PEEK and PEEK with 30% of carbon fiber, evaluated the effect of carbon fiber on wear rate and friction for turning counterbody finishing and the lubrication regime was for polishing and turning finishes for natural PEEK and polishing, honing, grinding and turning for PEEK with 30% of carbon fiber under 2 MPa and 2 m/s. It was found that steady state of wear occurred from 60 minutes of test after wear rate and friction coefficient stabilization. The friction and wear of PEEK and its composites were sensitive to the counterbody finishing; it was the main factor which defined the lubrication regimes. In the above test conditions polishing operated in hydrodynamic regime, turning and grinding on boundary condition and honing in mixed regime. The Stribeck curve was raised for PEEK with 30% carbon fiber by sliding against the honing finishing disk under 1 MPa to 14 MPa of apparent pressure range. Under these conditions the three main lubrication regimes were observed and it was possible to create a map that relates lubrication regime with pressure, speed and coefficient of friction.

Atualmente a área de saúde vem buscando auxílio na engenharia para a contribuição no estudo e confecção de próteses para casos específicos de fraturas ou doenças ósseas. Com o avanço da tecnologia surgiram processos de manufatura que tornam possível a fabricação de próteses personalizadas. Uma dessas tecnologias é a manufatura aditiva. O grande desafio no momento está na fabricação de próteses por manufatura aditiva que combinem desempenho biomecânico e resistência estrutural. Nesse contexto, o objetivo deste trabalho é desenvolver elementos de fixação, especificamente âncoras de sutura de polímeros PEEK e PEKK, considerando seus requisitos estruturais através de simulações pelo método dos elementos finitos, e considerando que sejam fabricadas através de processos de manufatura aditiva. Este desenvolvimento permitirá a substituição de âncoras de sutura de liga de titânio, hoje largamente empregadas pelos cirurgiões, por âncoras de sutura de polímeros biocompatíveis, o que possibilitará que estes polímeros sejam absorvidos pelo corpo humano em curto e médio prazo, permitindo a completa restituição do osso afetado, melhorando a qualidade de vida do paciente pós-cirurgia. Os resultados obtidos neste trabalho indicam que a técnica poderá resultar em próteses com a biocompatibilidade desejada e resistência mecânica adequada. Próteses permanentes (articulações) ou provisórias (âncoras de sutura) seriam um dos critérios para a escolha do material a ser utilizado, absorvível ou não pelo corpo humano. / Nowadays medicine is searching assistance from engineering that may contribute in studies and confection of prothesis to specific cases of fractures and bone diseases. With the advance of technology new processes of manufacture were risen, making possible the confection of personalized prothesis. The biggest challenge of the moment is in the manufacture of additive prothesis that can combine biomechanics performance and structural resistance. In this context, the objective of this dissertation is to develop PEEK and PEKK polymer suture anchors, considering its structural requirements, taking into account their mechanical strength, through simulation by the finite element method, and considering additive manufacturing processes. This development will allow the replacement of titanium alloy suture anchors, now widely used by surgeons by suture anchors of biocompatible polymers, which enable these polymers to be absorbed by the human body in the short and medium term, allowing full regeneration of affected bone, improving the quality of life of the patient. The results of this study indicate that the technique could result in prosthesis with the desired biocompatibility and adequate mechanical strength. Permanent prosthesis (joints) or temporary (suture anchors) would be one of the criteria for the choice of material to be used, absorbable or non absorbable by the human body.

Le poly-aryl-éther-éther-cétone (PEEK) est un polymère thermoplastique qualifié de haute performance. Celui-ci suscite l’intérêt de la recherche et de l’industrie pour ses propriétés mécaniques remarquables et sa grande stabilité chimique. Cependant, le PEEK reste relativement sensible à l’usure. Le dépôt d’un revêtement dur à la surface d’un matériau sujet à l’usure est un moyen de protéger ce dernier de l’usure. Les revêtements de type diamond-like carbon (DLC) sont des matériaux connus pour avoir une très bonne résistance à l’usure permettant de protéger efficacement les substrats sur lesquels ils sont déposés. La génération d’une texturation à la surface du matériau d’intérêt est un autre moyen de contrôler son usure. Les lasers femtosecondes se révèlent être des dispositifs très intéressants pour réaliser rapidement des texturations de grande précision. Les travaux présentés dans ce mémoire ont pour objectif de combiner le dépôt d’un revêtement de surface de type DLC et la texturation de surface par laser femtoseconde afin d’améliorer les performances tribologiques du PEEK. La démarche employée a consisté, dans un premier temps, à élaborer un revêtement DLC permettant de protéger efficacement le PEEK de l’usure et ayant une excellente adhérence avec celui-ci puis, à étudier l’influence de la texturation de surface, et plus précisément l’influence des paramètres géométriques de la texturation, sur le comportement tribologique du PEEK revêtu de DLC. / Poly-ether-ether-ketone (PEEK) is a thermoplastic polymer which is often described as a high performance polymer. It is a material subjected to intensive academic and industrial researches for its remarkable bulk mechanical properties and its high chemical stability. However, PEEK is relatively sensitive to wear. The deposition of hard coatings onto materials subjected to wear is a means of protecting them from wear. Diamond-like carbon (DLC) coatings are known to be highly resistant to wear allowing to efficiently protect the substrate onto which they are deposited. Surface texturing is another means of controlling wear. Femtosecond lasers have proven to be very interesting devices in order to quickly produce high-precision textured surfaces. The work presented in this thesis aims at combining the deposition of a DLC coating and laser surface texturing in order to improve the tribological properties of PEEK. The approach was first to develop a highly adherent DLC coating able to efficiently protect the PEEK substrate from wear and then to study the influence of surface texturing, and more precisely the influence of some geometrical parameters, on the tribological behavior of the DLC-coated PEEK. Tt

The conventional manufacturing methods, such as milling and turning, are reliable methods which makes them commonly used. These methods are capable of producing high precision details with high surface quality. But there are drawbacks and limitations. Many of these methods are expensive and require high production volume to be profitable. The design constraints for conventional manufacturing methods are usually determined by the machining tools, which restrict shape and form.Additive manufacturing methods have gained high attraction in the last decades as an alternative to conventional methods. With greater design freedom, ease to use interface and minimal material waste, cost and time usage can be minimized. But changing the production process requires high knowledge of capability and limitations for these methods. This step is critical to assure the right detail and quality requirements. Additive manufacturing at present is limited to material selection, low precision and possibility of reduced mechanical properties. This report aims to investigate additive manufacturing and the possibility of replacing conventional manufacturing of tools and products. / De traditionella tillverkningsmetoderna (TT), exempelvis fräsning eller svarvning, är något många företag använder sig av för att bearbeta fram sina produkter. Dessa processer ger hög precision, snäva toleranser och en god ytfinish vid tillverkning. Men som för alla processer finns även nackdelar och begränsningar. Många av dessa processer är väldigt dyra och kräver större tillverkningsvolymer för att bli lönsamma. De har även begränsningar i frihet vid formgivning och kräver bland annat större kunskap hos operatören och leder till materialspill. På senare tid har additiva tillverkningsmetoder (AT) lockat många tillverkare för att byta ut de traditionella processerna. Med sin frihet i formgivning, enkelhet och diversitet ser man potential i att spara både tid och pengar. Men att byta ut nuvarande produktionsmetod kräver god förståelse av den nya metodens kapacitet och begränsningar. Detta för att kunna säkerställa kvalitetskrav för det tänkta arbetet. AT i dagens läge är begränsad till materialval, ger långt ifrån de snäva toleranser som kan åstadkommas med traditionella tillverkningsmetoderna, och kan påverka de mekaniska egenskaperna hos den tillverkade detaljen negativt. Vissa AT metoder kräver dessutom höga investeringskostnader och det visar sig inte alltid vara mer lönsamt mot traditionella tillverkningsmetoder. I detta arbete ska just detta undersökas och huruvida AT kan konkurrera med traditionella tillverkningsmetoder, samt hur AT kan säkerställa de krav som finns på befintlig produktion av detaljer. Detta arbete är en förstudie om additiv tillverkning och dess möjligheter att ersätta befintlig produktion av verktyg och produkter.

The ever-growing Internet of Things is promoting more data acquisition, data exchange and fewer human interactions, engendering a higher demand for sensors and therefore power. While in most cases it is possible to directly connect these sensors to the power grid, it will not always be feasible with emerging technologies, especially in remote areas where human access is limited. Moisture-Electric Energy Transformation (MEET) devices are components that use moisture as a “fuel” to generate electrical power. Upon contact with moisture, a potential difference results from a diffusion mechanism, allowing charge to be stored locally in capacitors or rechargeable batteries to be utilized for useful work. The focus of the present work was to investigate the potential of Cold Gas Dynamic Spray (CGDS) as an additive manufacturing (AM) process for the fabrication of MEET devices. Following a layer-by-layer approach, MEET devices were successfully built by CGDS, by combining aluminum (electrode material) and an in-situ composite of polyether ether ketone (PEEK) and alumina (diffusion medium). The main challenges of this work were the determination of the spray parameters of PEEK and the investigation of the MEET capability of the manufactured devices. On the other hand, the main contributions of this work were the demonstration of the viability of CGDS in the deposition of PEEK/Al2O3 on aluminum 6061-T6 substrates, as well as the potential of PEEK as a MEET-capable material. The diffusion mechanisms that govern power generation were also hypothesized, explained and summarized. Initial tests of a MEET device of 66 mm x 34 mm indicate an uninterrupted power generation cycle of over 30 hours, and a maximum output voltage of 268 mV with a 6.8 MΩ load. The output power and power per unit area of the device were computed to be 10.63 nW and 4.736 µW/m2 respectively. The output current and current density were evaluated to 39.53 nA and 17.62 µA/m2.