Orientadores: Flavio Henrique Baggio Aguiar, Jose Roberto Lovadino / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T11:37:42Z (GMT). No. of bitstreams: 1 Soares_GiullianaPanfiglio_M.pdf: 730604 bytes, checksum: 4496655ec779f61c3be30cc95bf5663a (MD5) Previous issue date: 2009 / Resumo: A manutenção da integridade entre dente e restauração é importante para o sucesso clínico de restaurações adesivas, influenciando a longevidade das mesmas. Assim, o objetivo deste trabalho "in vitro", composto por dois experimentos, foi avaliar a infiltração marginal em cavidades Classe II: 1) confeccionadas com um sistema adesivo e compósito dental, variando a fonte de luz e o tempo de fotoativação do sistema adesivo, submetidos aos testes de ciclagem mecânica e térmica; 2) confeccionadas com um sistema adesivo e um compósito dental, variando a fonte de luz e o tempo de fotoativação da resina composta, submetidos ou não aos testes de ciclagem mecânica e térmica. Para tanto foram utilizados 270 dentes bovinos no qual foram realizadas restaurações Classe II variando o aparelho e o tempo de fotoativação, aplicado no sistema adesivo ou resina composta. Após isto, as restaurações foram submetidas ao teste infiltração marginal. De acordo com os resultados obtidos (Análise de Variância (p=0,05) e teste de Tukey) e sob as condições experimentais deste estudo, pôde-se concluir que: 1) o aumento do tempo de fotoativação do sistema adesivo não mostrou melhores resultados no processo de infiltração marginal, independente da fonte luz utilizada; 2) o aumento do tempo de fotoativação da resina composta não mostrou melhores resultados no processo de infiltração marginal, independente da fonte luz utilizada; 3) a utilização de aparelhos fotopolimerizadores com maiores intensidades de luz não mostrou melhores resultados quando comparados ao de menor intensidade, quando utilizados paar fotoativação da resina composta; 4) houve aumento da infiltração marginal após os testes de ciclagem mecânica e térmica nos grupos LED 3a geração e halógena quando estes foram utilizados para fotoativação da resina composta. / Abstract: The maintenance of the bond integrity between tooth and resin systems is important for the clinical success of composite resin restorations. Thus, the aim of this "in vitro" study composed of two manuscripts, was to evaluate the microleakage of Class II dental restorations: 1) made with an adhesive system and a dental composite, varying light curing time and light curing modes of the adhesive system, submitted to the thermal and mechanical loading cycling; 2) made with an adhesive system and a dental composite, varying light curing time and light curing modes of the resin, submitted or not to the thermal and mechanical loading cycling. 270 bovine teeth were used for this study, and prepared Class II restorations varying the time and the light curing modes for the adhesive or composite resin. After that, the restorations were submitted to the microleakage test. Based on the results (Analysis of Variance (p=0,05) and Tukey test), within the experimental limits of this study, it can be concluded that: 1) the increase of the light curing time of an adhesive system did not show better results in the process of marginal microleakage, regardless the light curing modes used; 2) increasing the photoactivation time of the resin composite did not reduce the microleakage of the cervical interface of the restoration, regardless the light curing modes used; 3) use of light curing units with high irradiance did not show better results when compared with low irradiant energy, for the two first layers of resin composite; 4) the thermal and mechanical loading cycling increased the microleakage in groups LED 3a generation and Conventional (QTH) for the two first layers of resin composite. / Mestrado / Dentística / Mestre em Clínica Odontológica

Orientador: Rafael Leonardo Xediek Consani / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-09T18:24:15Z (GMT). No. of bitstreams: 1 Lira_AndreaFabianade_M.pdf: 707416 bytes, checksum: 69b11fb51b91c668991278766f976aa6 (MD5) Previous issue date: 2007 / Resumo: O propósito deste trabalho foi estudar o efeito de métodos de contensão da mufla metálica (grampo convencional e sistema RS de contensão) e do tempo pós-prensagem (imediato e 6 horas) nos níveis de adaptação da base de prótese total superior confeccionada com as resinas acrílicas ativadas termicamente Clássico (Clássico) e QC-20 (Dentsply). Foram confeccionados 80 conjuntos modelo de gesso-base de cera distribuídos aleatoriamente em 8 grupos (n=10), de acordo com os métodos de contensão de mufla metálica e do tempo pós-prensagem. As resinas acrílicas foram proporcionadas e manipuladas de acordo com as instruções dos fabricantes e prensadas na fase plástica, com carga inicial de 850 kgf e final de 1250 kgf em prensa hidráulica de bancada. As bases confeccionadas em resina Clássico foram polimerizadas em ciclo de água a 74?C por 9 horas e as bases de resina QC-20 em água em ebulição por 20 minutos. Depois de esfriadas até atingir a temperatura ambiente, as bases foram desincluídas, acabadas, fixadas nos respectivos modelos de gesso com adesivo à base de cianoacrilato e seccionadas em três secções, correspondentes à distal de caninos, mesial de primeiros molares e região palatina posterior. Em cada secção, o desajuste entre modelo de gesso e base de resina foi verificado nos pontos referenciais fundo de sulco vestibular direito e esquerdo, crista do rebordo alveolar direito e esquerdo e linha mediana palatina posterior, com microscópio comparador linear Olympus, com precisão de 0,0005 mm. Os resultados coletados foram submetidos à análise de variância e ao teste de Tukey (5%). O dispositivo RS produziu níveis médios de adaptação com diferença estatística significante quando comparado com o grampo convencional, independente dos demais fatores. O dispositivo RS produziu níveis médios de adaptação nos tempos imediato e 6 horas com diferença estatística significante quando comparado com o grampo convencional. A polimerização imediata produziu valores entre cortes sem diferença estatística significativa quando comparada com a polimerização após 6 horas. Quando os cortes foram analisados no fator prensagem, os melhores níveis de adaptação foram obtidos com o dispositivo RS, com diferença estatística significativa quando comparado com o grampo convencional. Os tratamentos RS e convencional apresentaram comportamento semelhante, independente da resina, mas foram diferentes no tempo pós-prensagem. A região posterior apresentou maiores valores de desadaptação em ambas as resinas, independente do tipo de contensão da mufla e do tempo pós-prensagem / Abstract: The purpose of this study was to verify the effect of flask closure method (conventional clamp and RS tension system) and post-pressing time (immediate and after 6 hours) on the maxillary denture base adaptation made with Classico and QC-20 heat?cured acrylic resins. Eighty maxillary stone cast/wax base sets were made and randomly assigned into 8 groups (n=10) according to the flask closure method and post- pressing time. The acrylic resins were proportioned and manipulated following the manufacturer?s instructions and flask pressed in the doughlike stage with an initial load of 850 kgf and final load of 1,250 kgf in hydraulic press. Classico acrylic resin was submitted to polymerization in water at 74°C during 9 hours in immediate or after 6 hour post-pressing times. QC-20 acrylic resin was submitted to polymerization in boiling water for 20 minutes. After bench cooling the resin bases were deflasked, finished, and fixed on the casts with instantaneous adhesive. The cast-resin base sets were laterally sectioned in the regions corresponding to the distal of canines (A), mesial of first molars (B), and posterior palatal zone (C). The gap between the stone cast and resin base was measured with an Olympus comparative microscope with accuracy of 0.0005mm at five referential points for each section. Data submitted to ANOVA and Tukey?s test (5%) showed that the RS system produced medium levels of adaptation with statistically significant difference when compared to the conventional clamp, independent of the other factors. RS system produced levels of adaptation in the immediate and 6 hours post-pressing times with statistical significant difference when compared to the conventional clamp. The immediate polymerization produced values among cuts without statistical difference when compared to the polymerization after 6 hours. When the cuts were analyzed in the factor flask pressure method, the best levels of adaptation were showed with the RS system, with statistical significant difference when compared to the conventional clamp. The RS system and conventional clamp treatments showed similar results independent of the resin factor; however they were different in the post-pressing time. The posterior region showed greater values of desadaptation in both resins, independent of the flask closure method and post-pressing time / Mestrado / Protese Dental / Mestre em Clínica Odontológica

Orientador: Mário Alexandre Coelho Sinhoreti / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T12:31:43Z (GMT). No. of bitstreams: 1 Grohmann_CaioViniciusSignorelli_M.pdf: 1289626 bytes, checksum: 3364946c62d131765f918bfae157fa67 (MD5) Previous issue date: 2013 / Resumo: O objetivo neste estudo foi determinar a influência da concentração e proporção de canforoquinona (CQ) e etil-dimetilaminobenzoato (amina terciária - DABE) em propriedades de compósitos microhíbridos experimentais. Foram testados o Grau de Conversão (GC), Amarelamento (AM), Módulo de Elasticidade (ME), Resistência à Flexão (RF), Sorção de Água (SO) e Solubilidade (SL). Para tanto, 10 compósitos experimentais com a mesma composição monomérica (Bis-GMA, UDMA, BisEMA e TEGDMA) foram manipulados, variando-se apenas as concentrações e proporções de CQ/DABE (% em peso): 0,4/0,4 (C1); 0,4/0,8 (C2); 0,6/0,6 (C3); 0,6/1,2 (C4); 0,8/0,8 (C5); 0,8/1,6 (C6); 1/1 (C7); 1/2 (C8); 1,5/1,5 (C9) e 1,5/3 (C10). Para o ensaio de GC, 8 espécimes de cada material foram confeccionados, a partir de uma matriz de silicone em forma de barra (comprimento = 7 mm; largura = 2mm e espessura = 1mm), os quais foram fotoativados com um aparelho LED (Radii Cal, SDI, 800 mW/cm2), durante 20 segundos. Após 24 horas, o GC foi analisado por Espectroscopia de Infravermelho Transformada de Fourier (FTIR). Posteriormente, as mesmas amostras foram submetidas ao ensaio de flexão de 3 pontos em máquina de ensaio universal (Instron), e a RF e ME calculados. Para os testes de AM, SO e SL, foi utilizada uma matriz de silicone cilíndrica (diâmetro = 6 mm e espessura = 0,5 mm), e confeccionadas 5 amostras de cada material para cada teste. Todas as amostras foram armazenadas em estufa a 37º C, até que fossem submetidas aos seus respectivos testes. O AM foi mensurado após 24 horas de armazenamento em água, utilizando o espectrofotômetro Chroma Meter CR-400 (Konica Minolta). A análise se baseou no eixo b* (+b = amarelo; -b = azul). Para os testes de SO e SL, as amostras foram dissecadas por 1 semana e pesadas diariamente até que a variação máxima de massa fosse de 0,0001 g de um dia para o outro, obtendo m1. Para obter m2, as amostras foram armazenadas em água por 1 semana e pesadas novamente, uma única vez. Por último, m3 foram obtidas do mesmo modo em que m1, após recondicionamento das amostras. Para o cálculo foram utilizadas as fórmulas: SO = (m2-m3) / V e SL = (m1-m3) / V. Após os testes, os dados foram submetidos ao ANOVA one-way e teste Tukey (5%). As diferentes concentrações e proporções de CQ e DABE não alteraram significativamente as propriedades de RF e SO. Por outro lado, o GC foi influenciado positivamente, seguindo a ordem crescente da concentração CQ/DABE (C1 a C10). A SL foi inversamente proporcional à concentração do sistema CQ/DABE. Já relacionado ao ME, observou-se valores diretamente proporcionais à porcentagem em volume de CQ/DABE. Os compósitos 9 e 10, com maiores concentrações de CQ, apresentaram maior AM, comparados aos demais. Pode-se concluir que as altas concentrações de CQ/DABE levaram às melhores propriedades, porém ao maior AM. O aumento na proporção do co-iniciador (DABE) não influenciou nas propriedades de todas as formulações experimentais / Abstract: The aim of this study was to determine the influence of the concentration and ratio of camphorquinone (CQ) and ethyl-dimethylaminobenzoic (tertiary amine - DABE) on properties of microhybrids experimental composites. It was tested Degree of Conversion (DC), Yellowing (YL), Elastic Modulus (EM), Flexural Strength (FS), Water Sorption (WSP) and Solubility (SL). For this, 10 experimental composites with the same monomer composition (Bis-GMA, UDMA, BisEMA and TEGDMA) were manipulated by varying the concentration and ratio of CQ / DABE (wt%): 0.4 / 0.4 (C1); 0.4 / 0.8 (C2); 0.6 / 0.6 (C3); 0.6 / 1.2 (C4); 0.8 / 0.8 (C5); 0. 8 / 1. 6 (C6); 1 / 1 (C7); 1 / 2 (C8); 1.5 / 1.5 (C9); 1.5 / 3 (C10). For DC testing, 8 specimens of each material were prepared from a matrix of silicone-shaped bar (length = 7 mm, width = 2 mm and thickness = 1mm), which were photoactivated with one LED unit (Radii Cal, SDI, 800 mW/cm²) for 20 seconds . After 24 hours, the DC was analyzed by Infrared Fourier Transformed (FTIR). Subsequently, the same samples were subjected to bending test of three points on a universal testing machine (Instron), and the FS and EM calculated. For testing of YL, WSP and SL was used an array of cylindrical silicon (diameter = 6 mm and thickness = 0.5 mm), and made 5 samples of each material for each test. All samples were stored at 37 º C until they were subjected to their respective tests. The YL was measured after 24 hours of storage in water using the spectrophotometer Chroma Meter CR-400 (Konica Minolta). The analysis was based on the axis b * (+ b = yellow,-b = blue). For testing WSP and SL, the samples were dissected for 1 week and weighed daily until the maximum variation in weight was 0.0001 g of an overnight, obtaining m1. For m2, the samples were stored in water for 1 week and weighed once again. Finally, m3 were obtained in the same manner in which m1, after reconditioning of samples. For the calculation, were used: WSP = (m2-m3) / V and SL = (m1-m3) / V. After the tests, the data were subjected to one-way ANOVA and Tukey test (5%). The different concentration and ratio of CQ and DABE not significantly altered the properties of FS and WSP. Moreover, the DC was influenced positively in the order of increasing concentration of CQ / DABE (C1 to C10). The SL was inversely proportional to the concentration of the system CQ / DABE. Related to EM, was observed values directly proportional to the percentage by volume of CQ / DABE. The composites 9 and 10, with higher concentration of CQ showed higher YL, compared to the others. It can be concluded that high concentrations of CQ / DABE took the best properties, but the larger YL. The increase in the proportion of co-initiator (DABE) did not affect the properties of all experimental formulations / Mestrado / Materiais Dentarios / Mestre em Materiais Dentários

De par leurs faible coût, légèreté et propriétés thermiques, les co-produits lignocellulosiques ont reçu une attention particulière pour la fabrication de bétons légers. Cependant ces co-produits ne sont pas totalement compatibles avec une matrice cimentaire, d'où un retard de prise, des variations dimensionnelles élevées et des résistances mécaniques faibles des matériaux résultants. Pour pallier ces inconvénients, un procédé d'enrobage d'anas de lin avec différentes substances a été adopté. Les composites élaborés présentent des améliorations significatives de leurs comportement hydrique et résistances mécaniques avec une augmentation modérée de masse volumique apparente et de conductivité thermique. Les phénomènes de transfert d'humidité dans les composites obtenus peuvent influencer de manière significative leur durabilité et performance. En effet la plupart des matériaux utilisés dans le bâtiment sont poreux, contenant de l'eau sous forme vapeur ou liquide. La perméabilité à la vapeur d'eau, les isothermes de sorption et la capacité tampon à la vapeur d’eau ont donc été déterminées. Les résultats obtenus montrent la bonne performance hygrique des éco-composites élaborés. Trois tests de lixiviation ont été proposés pour identifier la spéciation chimique des matériaux et évaluer leurs relargages. Les conditions expérimentales ont été choisies pour simuler différents états des composites dans des environnements externes en service ou fin de vie. Le comportement à la lixiviation des composites élaborés diffère peu selon le traitement subi par les anas et la libération de substances toxiques n'a pas été mise en évidence / Due to their low cost, lightness and thermal properties, lignocellulosic byproducts received a particular attention, in the recent years, for manufacturing lightweight concretes. However, these byproducts are not fully compatible with the cement matrix, leading to setting delay, significant dimensional variations, and low mechanical strengths of the composites elaborated. To avoid such drawbacks, a coating process of flax shives using different substances has been adopted in this study. It leads to a reduction in treated shive water absorption compared to raw shives. The composites obtained exhibit significant improvements in hydrous behavior and mechanical strengths with moderate increase in the apparent bulk density and thermal conductivity. The phenomena of moisture transfer in the produced composites can significantly influence the durability and performance of them. In fact most of the materials used in the building area are porous, containing water as vapor or liquid. Therefore the water vapour permeability, sorption isotherms and moisture buffering capacity have been determined. The results obtained show the good hygric performance of the eco-composites elaborated. Three leaching tests have been proposed in this study to identify the chemical speciation of the materials and to evaluate their releasing into the environment. The experimental conditions of the leaching tests have been chosen to simulate different states of our composites in external environments in service or end of life. The leaching behaviour of the cement-based products elaborated differs little according to flax shive treatment and the leaching of toxic substances has not been identified

L’objectif de cette thèse est d’explorer les techniques de croisement d’indicateurs spatialisés pour caractériser le cumul et les interrelations des inégalités territoriales, environnementales et sociales de santé (ITESS). Cette analyse implique la mise en place d’approches intégrées basées sur des données représentatives sur les échelles d’analyse, des techniques de traitement adaptées aux spécificités des données agrégées et une modélisation adéquate des phénomènes caractérisés. Un aspect spécifique de ces travaux est la construction d’un outil permettant l’intégration des phénomènes spatiaux à différents niveaux (local, régional et loco-régional). Dans ce projet, une étude pilote est présentée sur la région Picardie. L’outil a été testé pour l’analyse des ITESS, validant ainsi la faisabilité de la méthodologie et permettant l’adaptation des démarches mises en œuvre tout en apportant des clefs d’interprétation supplémentaires aux limites relatives d’appropriation directe des résultats par les gestionnaires / The objective of this thesis is to explore spatial indicator crossing-analysis techniques in order to characterize the accumulation and the interrelations of the territorial, environmental and social health (TESHI).This analysis implies to set up integrated approaches based on data representativeness, techniques adapted to specificities of aggregated data, and relevant modeling of the characterized phenomena. A specific aspect of this work is the development of a tool allowing the integration of spatial phenomena at different levels (local, regional and loco-regional). In this project, a pilot study is presented on the Picardy region. The tool has been tested for the analysis of TESHI, thus validating the methodology feasibility and the adaptation of approaches implemented while providing additional keys of interpretation to the relative limits of direct appropriation of the results by the managers

Evènement rare, un incendie au sein ou à l’extérieur d’un avion peut avoir des conséquences catastrophiques pour l’intégrité de l’appareil et de ses occupants. Les aéronefs sont donc dimensionnés pour répondre aux nombreuses exigences définies par les Autorités de certification. Le respect de ces exigences doit être démontré au travers d’essais de certification sur des échantillons de dimensions réduites avec des bruleurs standardisés. Dans une démarche de virtualisation d’essais, le développement d’outils prédictifs du comportement thermophysiques des structures composites soumises à un feu est un objectif ambitieux et très prometteur. Face à la complexité des nombreux phénomènes physiques mis en jeux (thermo-dégradation, dégazage, inflammation de gaz de pyrolyse, érosion, etc.), une méthodologie de modélisation incrémentale a été suivie partant de modèles simples pour aboutir au développement d’un modèle 3D du comportement thermochimique du composite T700/M21 soumis au feu. Ce modèle est basé sur une étude phénoménologique du comportement du composite grâce au développement d’un test au feu innovant et maitrisé. En outre, toutes les données d’entrée sont issues de mesure expérimentale de propriétés thermophysiques en utilisant des méthodes de caractérisation existantes et innovantes. In fine, la comparaison des profils de température et de la perte de masse mesurés du composite avec les résultats numériques montre la capacité du modèle à prédire ce comportement au feu. / Rare event, an aircraft in fire can lead to disastrous consequences for the integrity of the plane and its passengers. The aircraft are thus dimensioned in order to comply with the large number of requirements defined by the certification Authorities. The respect of these standards has to be demonstrated via certification tests on structure panels of reduced size using standardized burners. In a virtual testing approach, the development of predictive tools of the thermomechanical behaviour of the composite exposed to fire is an ambitious objective and very promising. With regards to the complexity of the many physical phenomena involved in the combustion process (thermodegradation, out-gassing, ignition of gases, erosion, etc.), an incremental modelling methodology has been followed starting with basic model to finally succeed to develop a 3D model of the thermochemical behaviour of the T700/M21 composite exposed to fire. This model is based on a phenomenological study of the behaviour of the composite using a novel versatile fire test which was developed in a totally controlled way. In addition, all inputs are obtained from measurements of thermophysical properties using existing and innovative characterisation methods. In fine, the comparison of the measured temperature profiles and the mass loss of the composite with the numerical results show the capability of the model to predict the fire behaviour of the material.

A thesis submitted in compliance with the requirements for the Master's Degree in Technology: Mechanical Engineering, Durban Institution of Technology, 2003. / Composites have become important engineering materials, especially in the fields of automotive, aerospace and marine engineering. This is due to the high specific strength and stiffness properties they offer. At present, fibre-reinforced plastic (FRP) laminates are some of the most common types of composite used. They are produced in various forms with different structural properties. As with all engineering materials, there is the existence of both advantages and disadvantages. One of the main disadvantages is the expense involved in producing both the material and the finished product. The design time is also costly as the material has to be designed concurrently with the structure. / M

The present work is a study of the matrix cracking behaviour of composite laminates which contain plies oriented at an angle to the loading axis. Incremental tensile tests were conducted on a set of glass-epoxy laminates having the [0/θ][formula omitted] geometry where θ takes the values of 45°, 60°, 75° and 90°. At each load increment, the stiffness reduction was measured and the cracking sequence was photographed. A novel technique using image analysis was used to measure the crack length and digitize the crack pattern in each photograph. The results were analysed in two ways - deterministically (using fracture mechanics) and statistically. In the first instance, the relationship between stiffness loss and crack length was used to calculate the strain energy release rate, G from a compliance expression. It was found that the overall stiffness loss for a given crack length increased with increasing θ. As G can also be viewed as the resistance to cracking, the calculated values were used to plot matrix cracking resistance curves (R-curves) for each lay-up. The R-curves showed that the overall resistance to cracking increased with increasing orientation angle, θ. For the [0/45][formula omitted] laminate, where cracking is driven by the highest proportion of G₁₁ component, the least increase in resistance was observed. The differences in crack resistance in these lay-ups could be explained with results from the statistical analysis. A statistical analysis of the changes in distribution of crack length and number indicated that most of cracks in the [0/90][formula omitted] were short even at high loads. In addition, a calculation of the incremental growth with each incremental load showed that the amount of growth in that lay-up was limited. This implied that the process of crack initiation continually dominated crack propagation even late in the loading sequence. The opposite behaviour is seen as θ decreases. In the [0/45][formula omitted], [0/60][formula omitted], and [0/75][formula omitted] lay-ups, the additional Mode II shear loading appeared to have assisted significantly the coalescence and growth of cracks. Hence, the overall crack resistance decreased as the proportion of the GH component increased. Cracking in the off-axis plies is not uniform. In the [0/45][formula omitted], [0/60][formula omitted] and [0/75][formula omitted] laminates, cracking begins in distinct bands and are referred to as shear bands since they occur due to the presence of the Mode II shear loading. This phenomenon, however, has little effect on the stiffness. Although cracking is not uniform, the cracks tend to space themselves to within two ply thickness apart as crack density increases. In the shear band areas, the crack spacing can approach one ply thickness. It was also observed that crack tips stop growing either when they are two ply thickness apart or when they approach a stronger area in the laminate. Generally, the resistance to cracking is not affected when the crack density is low. However, as cracks begin to interact when they are spaced to within two ply thickness, the resistance increases dramatically. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

Composites are increasingly used in aerospace applications where performance is the foremost priority of industry. Research on carbon nanotube (CNT)-reinforced polymers conducted in the past decade showed promising results for the improvement of mechanical, thermal and electrical properties of composites. This thesis was undertaken in the context of a larger project, the main goal of which is to develop a complete solution for the manufacturing of carbon fibre-epoxy composites using CNT-reinforced epoxies, referred to as multi-scale composites. This thesis focuses on the thermal aspect of this project under three topics: 1) thermal conductivity of dry carbon fibre fabrics for understanding heat diffusion in composites and similar fabric materials 2) thermal conductivity of CNTreinforced polymers and composites for determining the effect of parameters including CNT addition, and 3) modelling of heat transfer during composite manufacturing for ensuring that their temperature distribution remains controlled. In-plane k rip and through-thickness k rtt thermal conductivity data were measured for two dry carbon fibre fabrics as a function of fibre volume fraction Vf . Results showed that k rip varies linearly with Vf whilst k rtt varies in an exponential recovery trend with Vf . An existing analytical model was used successfully for predicting k rip and simulations developed for predicting k rtt values demonstrated that k rtt depends on the evolution of heat conduction paths in the through-thickness direction as a result of improvements in the fibre contact network. A procedure was developed for manufacturing composites using the RFI process. Thirty-two composites and multi-scale composite plates were manufactured and characterised for investigating the effects of eleven material and manufacturing parameters on fibre volume fraction, porosity, k rip and k rtt . Results showed that the effect of using multi-walled CNT-reinforced epoxy on thermal conductivity of composites is negligible at 0.3% CNT loading. However, this reduced the porosity of the composites significantly. Results also showed that using fabrics with higher surface densities led to a slight increase in k cip . A heat transfer model coupled with cure kinetics was developed for predicting temperature profiles of the laminate during RFI manufacturing. The model was validated experimentally and eleven simulation cases were run for investigating the effects of five material and manufacturing parameters on temperature profiles in the laminate. Results showed that the epoxy resins used in this project combined with the cure cycle recommended by the manufacturer are well-suited for manufacturing laminates with a typical thickness of approximately 5 mm as well as thick laminates of 15 mm to 20 mm.

Polylactic acid (PLA) is a well-known biodegradable and sustainable polymer, derived from renewable agricultural sources. Its high price in the past limited its applications to mainly biomedical materials such as bone fixation devices. As the growth of awareness in global environment protection and sustainable development, PLA has attracted increased attention and development. Nowadays, the applications of PLA have been broadened into plastics, textiles and composites etc. Composites have been widely used in industrial applications for several decades, due to their high strength-to-weight ratio and good structural properties. However, most traditional composite materials are composed of two distinct fossil fuel based components. They are not eco-friendly and are difficult to recycle. This study aims at the development of PLA biodegradable composites and the optimisation of the processing parameters to achieve the best mechanical properties of PLA self-reinforced composites (PLA-SRC) for various end-uses. A variety of polymer analytical techniques were used to evaluate crystallinity, thermal properties, and chemical structures of the PLA reinforcement and matrix. Further study was carried out to assess the effects on mechanical properties of PLA-SRC caused by the processing temperature, pressure and holding time. The composites produced at high temperature and/or high pressure have significantly better matrix penetration (fibre wetting), which enhances mechanical properties. However, holding time was found to have no significant effect on the properties of PLA-SRC.