Submitted by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2017-07-18T12:00:27Z No. of bitstreams: 1 arquivototal.pdf: 3670112 bytes, checksum: d762a13cb07012ebb6bb3db0a6e3d4d6 (MD5) / Made available in DSpace on 2017-07-18T12:00:27Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3670112 bytes, checksum: d762a13cb07012ebb6bb3db0a6e3d4d6 (MD5) Previous issue date: 2016-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The accumulated water on pavement surfaces is one of the factors responsible for the occurrence of traffic accidents, as it reduces the tire-pavement interface friction. The use of porous asphalt mixtures can increase road safety because it increases the adherence between a vehicle's tires and the pavement, especially in a wet highway, owing to its high drainage capacity. Accordingly, this research had the purpose of analyzing the use of polyethylene terephthalate (PET) waste as an alternative of additives to porous asphalt mixtures. The work method consisted of materials characterization, determination of the optimum binder content, production of three kinds of asphalt mixtures (conventional, with the addition of PET, and with polymer asphalt) and the performance of draindown tests, moisture susceptibility, resilient modulus, flow number, fatigue test, permeability to the asphalt mixtures, in their respective optimum binder contents. The PET was added to the mixtures by a dry process in the proportions of: 0; 0,33; 0,5; 0,75 e 1% regarding to the weight of the aggregates. The asphalt mixtures with polymer asphalt were taken as reference. Considering the mixtures design, additions of 0,75% PET up carried out the lowest optimum binder content. Besides that, the addition of PET contributed for a binder draindown inhibition and improved the mixtures performance regarding to moisture susceptibility. The PET additivated mixtures presented an increasing in the resilient modulus and a tendency of a longer fatigue life at low tension levels and high number of load applications. However, the mixtures are susceptible to rutting, even though presenting stiffening. Concerning to permeability, the execution of only one test became inconclusive. Although, it was verified that PET can present viability of being used as additive porous asphalt mixtures. / A água acumulada sobre a superfície do pavimento é uma das responsáveis pela ocorrência de acidentes em rodovias, por reduzir o atrito na interface pneu-pavimento. A adoção de misturas asfálticas porosas pode aumentar a segurança viária, pois seu uso favorece a aderência entre os pneus dos veículos e o pavimento, especialmente em pista molhada, tendo em vista a sua alta capacidade de drenagem. Diante disso, esta pesquisa objetivou analisar o uso de resíduos de politereftalato de etileno (PET) como aditivo para misturas asfálticas porosas. O método de trabalho consistiu na realização de ensaios de caracterização dos materiais utilizados, determinação do teor de projeto de ligante asfáltico, confecção de três tipos de misturas asfálticas (convencional, com adição de PET e com asfalto polímero) e realização de ensaios de escorrimento, dano por umidade induzida, módulo de resiliência, deformação permanente, vida de fadiga e permeabilidade para as misturas asfálticas, em seus respectivos teores de projeto de ligante asfáltico. A adição de PET nas misturas foi realizada via processo seco nas proporções 0,00; 0,33; 0,50; 0,75 e 1,00% em relação ao peso dos agregados. As misturas asfálticas com asfalto modificado por polímero foram tomadas como referência, tendo em vista a preferência do uso desse tipo de ligante em misturas porosas. Em termos de dosagem, adições de PET em até 0,75% resultaram na redução do teor de projeto de ligante asfáltico. Além disso, o PET contribuiu para a inibição do escorrimento do ligante e favoreceu o desempenho das misturas em relação ao dano por umidade induzida. As misturas aditivadas com PET apresentaram um aumento no módulo de resiliência e uma tendência de maior vida de fadiga para baixos níveis de tensões e elevadas repetições de carga. Porém, mostraram-se suscetíveis à deformação permanente, mesmo tendo apresentado um maior enrijecimento. Quanto a permeabilidade, é necessário a realização de mais ensaios de modo a garantir uma melhor confiabilidade nos resultados. De todo modo, pôde-se verificar que o PET pode apresentar viabilidade de ser utilizado como aditivos em misturas asfálticas porosas.

A moldagem de pós por injeção (MPI) foi empregada neste trabalho para a fabricação de micro componentes de uma pinça de biópsia, através do desenvolvimento de misturas injetáveis. Utilizou-se a liga de aço inoxidável AISI 316L, liga reconhecidamente biocompatível, para obtenção dos micro componentes. Determinando a quantidade de 39% em volume para fração orgânica das quatro formulações de misturas injetáveis produzidas neste trabalho. Os polímeros estruturais empregados foram o PP, o PEBDL, o PEAD e o PMMA. Como material auxiliar de fluxo foi utilizada a parafina e para agente surfactante, o ácido esteárico. O desenvolvimento do sistema de extração química do polímero auxiliar de fluxo com solvente e posterior extração térmica do ligante em forno convencional e em um reator a plasma foram testados, ainda se empregou estes para testes em sinterização a temperaturas 1200°C, 1250°C e 1300°C. A extração química foi realizada com hexano atingindo 2,41% em massa de material extraído das amostras, após seis horas em um sistema aquecido entre 60°C e 70°C e uma atmosfera de vácuo. As amostras foram testadas química, física, mecânica e eletroquimicamente. Obteve-se os melhores resultados em termos de densificação de 7,05 g/cm³ para as amostras extraídas a plasma e sinterizadas a 1300 °C à vácuo em forno tubular. Isso significa uma densificação de 88,96% comparada a densidade do material comercial cuja a densidade é 7,93 g/cm³. As microdurezas encontradas nas amostras sinterizadas a 1300 °C em um forno convencional obtiveram valores de 208HV se mostrando maiores do que os 165HV obtido de um material maciço fabricado pelo extrusão e comercialmente vendido. Encontrou-se a dureza de 55HRB nas amostras processadas a 1300 °C, devido a presença de poros em componentes sinterizados. Nos componentes maciços foram medidos a dureza de 88HRB que foi maior que os resultados das amostras sinterizadas. As análises metalográficas mostraram um tamanho de grão variando entre, 30 e 50μm, se comparado ao tamanho de partícula médio do D90 de foi de 8,59 μm, se estima que este aumento foi entorno de três vezes e meia. Os testes químicos revelaram que a extração térmica em reatores a plasma melhoram significativamente os níveis de C, N, H e S quando comparados ao processo de extração térmica em forno convencional. A redução dos níveis de carbono residual, resultaram em diminuição do carboneto de cromo nas amostras, provocando uma menor corrosão. As amostras sinterizadas a 1200 °C a plasma apresentaram os melhores resultados de corrosão. / The powders injection molding (PIM) was used in this research, with objective to manufacture micro component, for application in biopsy forceps being developed injectable mixtures . It was used the powder stainless steel AISI 316L alloy, material biocompatible, to obtain the micro components. Through tests was determining the amount optimal volume in 39 % for the organic fraction of the four formulations of injectable mixtures produced in this research. The structural polymers used were PP , LLDPE , HDPE and PMMA . The paraffin was used as auxiliary material flow, the surfactant agent employed that was stearic acid . The development of chemical debiding and the thermal extraction for binder system, was used the conventional furnace and in a plasma reactor were tested also be employed for these tests sintering temperature 1200 ° C , 1250 °C and 1300 °C. Chemical extraction was performed with hexane achieving 2.41 % by extracted mass of sample material, after six hours in a heated system between 60 °C and 70 °C and a vacuum atmosphere. The samples were tested analysis by chemical , physical , mechanical and electrochemical.If it obtained the best results in terms of densification of 7.05g/cm ³ for plasma samples extracted and sintering at 1300 °C in vacuum tube furnace . This means densification of 88.96 % compared to the density of commercial material whose density is 7.93 g/cm ³ . The microhardness found in the samples sintered at 1300°C in a conventional furnace obtained 208HV microhardness showing larger than the commercial 165HV. Found that the HRB hardness of 55 in the samples processed at 1300 °C, due to the presence of pores in sintered parts. In the extruded components were measured hardness of 88HRB which was higher than the results of the sintered samples. The metallographic analysis showing a grain size ranging between 30 and 50μm , compared to the average particle size D90 was 8,59 microns is estimated that this increase was around three and half times . The chemical tests revealed that the thermal plasma extraction reactor significantly improve the levels of C, N , H and S compared to the process heat extraction in a conventional furnace . The residual carbon levels significantly improved, which helps to avoid the formation of chromium carbides , which aumnetou corrosion resistance . The best results in terms of corrosion were found for the samples sintered at 1200 ° C the plasma.

A moldagem de pós por injeção (MPI) foi empregada neste trabalho para a fabricação de micro componentes de uma pinça de biópsia, através do desenvolvimento de misturas injetáveis. Utilizou-se a liga de aço inoxidável AISI 316L, liga reconhecidamente biocompatível, para obtenção dos micro componentes. Determinando a quantidade de 39% em volume para fração orgânica das quatro formulações de misturas injetáveis produzidas neste trabalho. Os polímeros estruturais empregados foram o PP, o PEBDL, o PEAD e o PMMA. Como material auxiliar de fluxo foi utilizada a parafina e para agente surfactante, o ácido esteárico. O desenvolvimento do sistema de extração química do polímero auxiliar de fluxo com solvente e posterior extração térmica do ligante em forno convencional e em um reator a plasma foram testados, ainda se empregou estes para testes em sinterização a temperaturas 1200°C, 1250°C e 1300°C. A extração química foi realizada com hexano atingindo 2,41% em massa de material extraído das amostras, após seis horas em um sistema aquecido entre 60°C e 70°C e uma atmosfera de vácuo. As amostras foram testadas química, física, mecânica e eletroquimicamente. Obteve-se os melhores resultados em termos de densificação de 7,05 g/cm³ para as amostras extraídas a plasma e sinterizadas a 1300 °C à vácuo em forno tubular. Isso significa uma densificação de 88,96% comparada a densidade do material comercial cuja a densidade é 7,93 g/cm³. As microdurezas encontradas nas amostras sinterizadas a 1300 °C em um forno convencional obtiveram valores de 208HV se mostrando maiores do que os 165HV obtido de um material maciço fabricado pelo extrusão e comercialmente vendido. Encontrou-se a dureza de 55HRB nas amostras processadas a 1300 °C, devido a presença de poros em componentes sinterizados. Nos componentes maciços foram medidos a dureza de 88HRB que foi maior que os resultados das amostras sinterizadas. As análises metalográficas mostraram um tamanho de grão variando entre, 30 e 50μm, se comparado ao tamanho de partícula médio do D90 de foi de 8,59 μm, se estima que este aumento foi entorno de três vezes e meia. Os testes químicos revelaram que a extração térmica em reatores a plasma melhoram significativamente os níveis de C, N, H e S quando comparados ao processo de extração térmica em forno convencional. A redução dos níveis de carbono residual, resultaram em diminuição do carboneto de cromo nas amostras, provocando uma menor corrosão. As amostras sinterizadas a 1200 °C a plasma apresentaram os melhores resultados de corrosão. / The powders injection molding (PIM) was used in this research, with objective to manufacture micro component, for application in biopsy forceps being developed injectable mixtures . It was used the powder stainless steel AISI 316L alloy, material biocompatible, to obtain the micro components. Through tests was determining the amount optimal volume in 39 % for the organic fraction of the four formulations of injectable mixtures produced in this research. The structural polymers used were PP , LLDPE , HDPE and PMMA . The paraffin was used as auxiliary material flow, the surfactant agent employed that was stearic acid . The development of chemical debiding and the thermal extraction for binder system, was used the conventional furnace and in a plasma reactor were tested also be employed for these tests sintering temperature 1200 ° C , 1250 °C and 1300 °C. Chemical extraction was performed with hexane achieving 2.41 % by extracted mass of sample material, after six hours in a heated system between 60 °C and 70 °C and a vacuum atmosphere. The samples were tested analysis by chemical , physical , mechanical and electrochemical.If it obtained the best results in terms of densification of 7.05g/cm ³ for plasma samples extracted and sintering at 1300 °C in vacuum tube furnace . This means densification of 88.96 % compared to the density of commercial material whose density is 7.93 g/cm ³ . The microhardness found in the samples sintered at 1300°C in a conventional furnace obtained 208HV microhardness showing larger than the commercial 165HV. Found that the HRB hardness of 55 in the samples processed at 1300 °C, due to the presence of pores in sintered parts. In the extruded components were measured hardness of 88HRB which was higher than the results of the sintered samples. The metallographic analysis showing a grain size ranging between 30 and 50μm , compared to the average particle size D90 was 8,59 microns is estimated that this increase was around three and half times . The chemical tests revealed that the thermal plasma extraction reactor significantly improve the levels of C, N , H and S compared to the process heat extraction in a conventional furnace . The residual carbon levels significantly improved, which helps to avoid the formation of chromium carbides , which aumnetou corrosion resistance . The best results in terms of corrosion were found for the samples sintered at 1200 ° C the plasma.

Made available in DSpace on 2015-04-11T13:47:50Z (GMT). No. of bitstreams: 1 TAYANA_CUNHA.pdf: 3246935 bytes, checksum: 4bfd4e26cc31d0040eded3e0c0d04580 (MD5) Previous issue date: 2011-02-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The study in question has researched the chemical and rheological properties of pure asphalt binder in Manaus (CAP 50/70-REMAN), and when modified with agents: synthetic polymer - a styrene-butadiene copolymer (SBS), natural fiber of fruits rind of Couepia edulis (Prance) (FCC) and antioxidant additive - fat Virola surinamensis - ucuúba (GU), aiming to bring benefits to the asphalt used in the region, as from the oxidative stress and heat, as well as a better performance of asphalt mixtures used in the process champion. Were determinate the properties of degradation and stabilization by thermal analysis - Termogravimetira (TG) and Differential Scanning Calorimetry (DSC), rheology, through Rheometer Dynamic Shear (Shear Rheometer Dynamical - DSR) under the parameters established in the specifications SUPERPAVE the aging process by thermoxidized (RTFOT) beyond the traditional characterization advocated by the National Petroleum Agency - ANP. The addition of modifying agents affected the physical, chemical and rheological properties, the main results: reduction in penetration rate, increase in softening point, good thermal stability and miscibility with the CAP, a significant increase in G* at low frequencies and decrease in tan δ, and the elevation of viscosity for the modified binders, but less pronounced by the presence of additive (GU). / comercializado em Manaus (CAP 50/70-REMAN), e quando modificado com os agentes: polímero sintético - copolímero de estireno e butadieno (SBS), fibra natural oriunda da casca da castanha de cutia (FCC) - Couepia edulis (Prance) e com aditivo antioxidante - gordura de Virola surinamensis ucuúba (GU), visando trazer benefícios ao asfalto utilizado na região, quanto ao efeito oxidativo e térmico, bem como quanto a um melhor desempenho das misturas asfálticas empregadas nas vias manauaras. Foram determinadas as propriedades de degradação e estabilização, pela análise térmica Termogravimetira (TG) e Calorimetria Exploratória Diferencial (DSC), o comportamento reológico, por meio do Reômetro de Cisalhamento dinâmico (Dynamical Shear Rheometer - DSR) segundo os parâmetros estabelecidos nas especificações SUPERPAVE, o envelhecimento pelo processo termoxidativo (RTFOT) além da caracterização tradicional preconizada pela Agência Nacional de Petróleo ANP. A adição de agentes modificadores afetou as propriedades físicas, químicas e reológicas, tendo como principais resultados: redução nos índice de penetração, aumento no ponto de amolecimento, boa estabilidade térmica e miscibilidade com o CAP, aumento significativo no G* em baixas freqüências e diminuição na tan δ, além da elevação da viscosidade para os ligantes modificados, porém menos pronunciada pela presença de aditivo (GU).

Le dragage des ports français génère chaque année entre 25 et 40 millions de tonnes de matériaux non contaminés qui sont clapés en mer. Il existe, de plus, un stock important de sédiments contaminés (10 millions de tonnes environ) qui n’ont pas été dragués, du fait de la réglementation interdisant un rejet en mer lorsque les niveaux de contamination dépassent les seuils définis par l’arrêté du 14 juin 2000. En outre, ce stock de sédiment, qui devra impérativement être dragué dans les dix ans à venir, est quasiment orphelin de filières de traitement et de valorisation adaptées. L’urgence de mettre en place des solutions (filières), respectueuses des fondements du développement durable, a engendré de nombreux programmes de recherche. Le programme SEDiGEST (Gestion des Sédiments de dragages des ports) envisage notamment un scénario de remblaiement des cavités terrestres par des sédiments traités. Cette Thèse de Doctorat, menée dans le cadre de ce programme, contribue à l’amélioration de la compréhension du comportement géo-physico-chimique d’un sédiment marin stabilisé aux liants hydrauliques (chaux + ciment). Pour répondre à cet objectif la démarche expérimentale a été conduite en trois étapes : tout d’abord la caractérisation du solide, puis l’évaluation de la mobilité potentielle des polluants inorganiques et enfin, la modélisation du comportement à la lixiviation. La synthèse des résultats a montré que les polluants inorganiques cibles de la matrice d’étude (cuivre, plomb et zinc) étaient majoritairement associés aux carbonates, aux sulfures/sulfates, aux (oxy)hydroxydes, et/ou à la matière organique. L’étude comparative de la matrice étudiée à trois stades « d’évolution » (avant et après traitement et vieilli artificiellement) a permis de mettre en évidence que le procédé de stabilisation aux liants hydrauliques n’était pas une solution pérenne. En effet, le sédiment traité présente un risque de pollution à plus ou moins long terme, notamment par relargage de plomb et de cuivre, en cas de carbonatation de la matrice sédimentaire. En particulier, la réversibilité du procédé de stabilisation/solidification induit par la réactivité des phases cimentaires avec le CO2 atmosphérique, peut également conduire à une mobilisation des polluants à long terme. / The dredging of French ports generates each year between 25 to 40 million tons of uncontaminated materials which are piled onto sea. Moreover, an important stock of contaminated sediments (about 10 million tons), which has to been dredged, exists. Indeed, the decree of June 14th, 2000 prohibits disposal to sea when levels of contamination exceed regulations. This important stock of sediment, which must be imperatively dredged within 10 years, is almost orphan of adapted treatment and valorization. In this context many research program appear to propose and to develop solutions. The SEDiGEST program (Management of the dredging sediments of ports) intends a scenario of filling terrestrial cavities with treated sediments. This Ph.D. thesis, carried out within the framework of this program, contributes to the improvement in understanding the geo-physico-chemical behavior of marine sediment stabilized with hydraulic binders (cement + lime). In this objective, the experimental approach was conducted in three steps. Firstly, a characterization of the solid was realized. An evaluation of the potential mobility of inorganic pollutants have was then determined. Finally, a modeling of the behavior towards leaching was operated. Data shown that target's inorganic pollutants of the matrix of study (copper, lead and zinc) were mainly associated with carbonates, sulfides/sulfates, (oxy)hydroxides, and/or with organic matter. Comparative study of the matrix at three levels “of evolution” (before and after treatment and artificially aged) highlights the reversibility of the stabilization by hydraulic binders. Indeed, treated sediment presents a pollution risk to less or more long term, leaching of copper and lead, during carbonation.

This thesis contains investigations in the area of polymers herein propellants binders are modified functionally to meet the requirements of future energetic propellants. Chapter 1 contains a broad introduction to the area of recent advances in solid propellants and the numerous applications of ‘Click Chemistry’. Chapters 2 details the materials, characterization tools and the experimental techniques employed for the studies. This is followed by Chapter 3, 4, and 5 which deals with functional modification of various propellants binders, their characterisation and evaluation in propellant formulations. Chapter 6 details with the thermal decomposition of diazides and its reaction with alkenes. The advent of modern rockets has opened a new era in the history of space exploration as well as defence applications. The driving force of the rocket emanates from the propellant – either solid or liquid. Composite solid propellants find an indispensable place, in today’s rockets and launch vehicles because of the inherent advantages such as high reliability, easy manufacturing, high thrust etc. The composite propellant consisting of inorganic oxidiser like ammonium perchlorate, (AP), ammonium nitrate (AN) etc), metallic fuel (aluminium powder, boron etc) and polymeric fuel binder (hydroxyl terminated polybutadiene-HTPB, polybutadiene-acrylic acid-acrylonitrile PBAN, glycidyl azide polymer (GAP), polyteramethylene oxide (PTMO) etc. is used in igniters, boosters, upper stage motors and special purpose motors in large launch vehicles. Large composite solid propellant grains or rocket motors in particular, demand adequate mechanical properties to enable them to withstand the stresses imposed during operation, handling, transportation and motor firing. They should also have a reasonably long ‘potlife’ to provide sufficient window for processing operations such as mixing and casting which makes the selection of binder with appropriate cure chemistry more challenging. In all composite solid propellants currently in use, polymers perform the role of a binder for the oxidiser, metallic fuel and other additives. It performs the dual role of imparting dimensional stability to the composite, provides structural integrity and good mechanical properties to the propellant besides acting as a fuel to impart the required energetics. Conventionally, the terminal hydroxyl groups in the binders like GAP, PTMO and HTPB are reacted with diisocyanates to form a polyurethane network, to impart the necessary mechanical properties to the propellant. A wide range of diisocyantes such as tolylene diisocyanate (TDI) and isophorone diisocyanate (IPDI) are used for curing of these binders. However, the incompatability of isocyanates with energetic oxidisers like ammonium dinitramide (ADN), hydrazinium nitroformate (HNF), short ‘potlife’ of the propellant slurry and undesirable side reactions with moisture are limiting factors which adversely affect the mechanical properties of curing binders through this route. The objective of the present study is to evolve an alternate approach of curing these binders is to make use of the 1,3 dipolar addition reactions between azide and alkyne groups which is a part of ‘Click chemistry’. This can be accomplished by the reaction of azide groups of GAP with triple bonds of alkynes and reactions of functionally modified HTPB/PTMO (azide/alkyne) to yield 1,2,3 -triazole based products. This offers an alternate route for processing of solid propellants wherein, the cured resins that have improved mechanical properties, better thermal stability and improved ballistic properties in view of the higher heat of decomposition resulting from the decomposition of the triazole groups. GAP is an azide containing energetic polymer. The azide groups can undergo reaction with alkynes to yield triazoles. In, Chapter 3 the synthesis and characterisation of various alkynyl compounds including bis propargyl succinate (BPS), bis propargyl adipate (BPA), bis propargyl sebacate (BPSc.) and bis propargyl oxy bisphenol A (BPB) for curing of GAP to yield triazoles networks are studied. The mechanism of the curing reaction of GAP with these alkynyl compounds was elucidated using a model compound viz. 2-azidoethoxyethane (AEE). The reaction mechanism has been analysed using Density Functional Theory (DFT) method. DFT based theoretical calculations implied marginal preference for 1, 5 addition over the 1, 4 addition for the uncatalysed cycloaddition reaction between azide and alkyne group. The detailed characterisation of these systems with respect to the cure kinetics, mechanical properties, dynamic mechanical behaviour and thermal decomposition characteristics were done and correlated to the structure of the network. The glass transition temperature (Tg), tensile strength and modulus of the system increased with crosslink density which in turn is, controlled by the azide to alkyne molar stoichiometry. Thermogravimetic analysis (TGA) showed better thermal stability for the GAP-triazole compared to GAP based urethanes. Though there have been a few reports on curing of GAP with alkynes, it is for the first time that a detailed characterisation of this system with respect to the cure kinetics, mechanical, dynamic mechanical, thermal decomposition mechanism of the polymer is being reported. To extent the concept of curing binders through 1,3 dipolar addition reaction, the binder HTPB as chemically transformed to propargyloxy carbonyl amine terminated polybutadiene (PrTPB) with azidoethoxy carbonyl amine terminated polybutadiene (AzTPB) and propargyloxy polybutadiene (PTPB). Similarly, PTMO was convnerted to propargyloxy polytetramethylene oxide (PTMP). Triazole-triazoline networks were derived by the reaction of the binders with alkyne/azide containing curing agents. The cure characteristics of these polymers (PrTPB with AzTPB, PTPB with GAP and PTMP with GAP) were studied by DSC. The detailed characterisations of the cured polymers for were done with respect to the, mechanical, dynamic mechanical behaviour and thermal decomposition characteristics were done. Propellant level studies were done using the triazoles derived from GAP, PrTPB-AzTPB, PTPB and PTMP as binder, in combination with ammonium perchlorate as oxidiser. The propellants were characterised with respect to rheological, mechanical, safety, as well as ballistic properties. From the studies, propellant formulations with improved energetics, safety characteristics, processability and mechanical properties as well defect free propellants could be developed using novel triazole crosslinked based binders. Chapter 6, is aimed at understanding the mechanism of thermal decomposition of diazido compounds in the first section. For this, synthesis and characterisation of a diazido ester 1,6 –bis (azidoacetoyloxy) hexane (HDBAA) was done. There have been no reports on the thermal decomposition mechanism of diazido compounds, where one azide group may influence the decomposition of the other. The thermal decomposition mechanism of the diazido ester were theoretically predicted by DFT method and corroborated by pyrolysis-GC-MS studies. In the second section of this chapter, the cure reaction of the diazido ester with the double bonds of HTPB has been investigated. The chapter 6B reports the mechanism of Cu (I) catalysed azide-alkene reaction validated using density functional theory (DFT) calculations in isomers of hexene (cis-3-hexene, trans-3-hexene and 2-methy pentene: model compound of HTPB) using HDBAA. This the first report on an isocyanate free curing of HTPB using an azide. Chapter 7 of the thesis summarizes the work carried out, the highlights and important findings of this work. The scope for future work such as development of high performance eco-friendly propellants based on triazoles in conjunction with chlorine-free oxidizer like ADN, synthesis of compatible plasticisers and suitable crosslinkers have been described. This work has given rise to one patent, three international publications and four papers in international conferences in the domain.

This thesis aims to optimize self-levelling floor screeds and thin layer screeds based on ternary binder system containing portland cement, calcium aluminate cement and gypsum with intentional ettringite formation. It also studies the influence of designed mixtures, chemical admixtures and aggregate granulometry on achieved technological characteristics required by standard.

The development of alternative binder systems for tungsten carbide (WC) based cemented carbides has again become of relevance due to possible changes in EU regulations regarding the use of Cobalt (Co). A framework for the ICME (Integrated Computational Materials Engineering) based Materials Design is presented to accelerate the development of alternative binder systems. Part one of this work deals with the design of the cemented carbide composite hardness. It has been shown that the intrinsic binder hardness is comparable to a bulk metal alloy and that based on the binder solubilities a solid solution strengthening model developed in this work can be employed. Using a method presented in this work the non-equilibrium, frozen-in binder solubilities can be obtained. Both the design of the binder phase and composite hardness is presented based on a general Materials Design approach. Part two deals with a multiscale approach to model the surface gradient formation. The experimentally missing data on liquid binder diffusion has been calculated using AIMD (Ab initio Molecular Dynamics). The diffusion through the liquid cemented carbide binder has to be reduced to an effective diffusion value due to the solid carbides acting as obstacles that increase the diffusion path. The geometrical reduction of the diffusion has been investigated experimentally using the SIMS (secondary ion mass spectroscopy) technique in WC-Nickel-58Nickel diffusion couples. The geometrical contribution of the so-called labyrinth factor has been proven by the combination of the experiments and in conjunction with DICTRA simulations using the precise liquid AIMD diffusivities. Unfortunately, despite the improved kinetic database and the geometrical diffusion reduction, the surface gradient formation cannot be explained satisfactory in complex cemented carbide grades. Additional, but so far unidentified, contributions have to be considered to predict the surface gradient thickness. / <p>QC 20170919</p>

The aim of this thesis is to automate the depowdering step in binder-jet additive manufacturing using KUKA kr6 robot. The major tasks involved in this thesis work are commissioning of the KUKA kr6 robot, plan the actions required for automation process of binder jet considering the scaling factor of green bodies. For this purpose KUKA robot with a standard KUKA compact controller (KRC4) and KUKA system software 8.3 (KSS) has been used. In Peter Corke Matlab toolbox (Matlab toolbox), KUKA kr6 robot model has been simulated to understand forward kinematics problem which shows the study the motion of end effector of robot in space for picking process. These transformations between the Joint coordinate systems and Cartesian coordinate systems give the forward and inverse kinematics. Firstly, a KUKA kr6 robot has been programmed in a KUKA Robot Language (KRL) using an algebraic approach with geometric operator to automate the picking process of green bodies. These are fragile bodies thereby many number of tests have been conducted to improve the program. Also additional effort has been placed to test the customized gripper used for the layered pick and place of the components, customized vacuum cleaner for the vacuum cleaning in between the layers and to consider the scaling factor during the sintering step of the binder jet. Finally, KUKA kr6 robot model has been simulated in Matlab toolbox. The picking point in the space has been simulated to study the forward kinematics and to understand how the robot reaches a position and orientation in space. Cartesian trajectory has been simulated. Also, the Jacobian matrix, its rank and determinant are studied to understand the singularities in KUKA kr6 robot, basing on which the thesis work can be continued and enhanced further.

3D woven composites, due to the presence of through-thickness fibre bridging, have the potential to improve damage tolerance and at the same time to reduce the manufacturing costs. However, the ability to withstand damage depends on weave architecture as well as the geometry of individual tows. A substantial amount of research has been performed to understand in-plane properties as well as the performance of 3D woven composites exposed to impact loads, but there is limited research on the damage tolerance and notch sensitivity of 3D weaves and no work is reported on the damage tolerance of 3D weaves with a weft binding pattern. In view of the recent interest in 3D woven composites, the influence of weft binder on the tensile, open hole tensile, impact resistance and subsequent residual compressive strength properties and failure mechanisms of 3D woven composites was investigated against equivalent UD cross-ply laminate. Four different 3D woven architectures; layer-to-layer, angle interlocked, twill angle interlock and modified angle interlock structures were produced under identical weaving conditions. All the above mentioned tests were performed in both the warp and weft directions on 3D woven and UD cross-ply laminates. Stress concentration and yarn waviness due to through-thickness reinforcement led to lower mechanical properties compared with the UD cross-ply laminate. However, improved in-plane and damage tolerance properties of 3D woven composites under tensile loads were achieved by modifying the weave architecture. The influence of the weave architecture and binder yarn orientation on the notch insensitivity and damage tolerance of 3D woven composites was less significant for compressive loads. Despite the lower undamaged compression strength of 3D woven structures, their residual compressive strength was found to be superior to their equivalent UD cross-ply laminates. The lower rate of strength reduction in the 3D woven fabrics laminates was attributed to a crack bridging mechanism, effectively inhibiting delamination propagation.