O objetivo desse trabalho foi desenvolver e caracterizar blendas poliméricas dos copolímeros de poli(hidroxibutirato-co-hidroxivalerato) (PHBV) com poli(etileno-coacetato de vinila) (EVA) contendo altos teores de acetato de vinila (VA). Os teores de VA nos EVA utilizados foram de 65% (EVA65) e 90% (EVA90) em massa. Como as propriedades finais das blendas de PHBV, copolímero derivado de fonte renovável e biocompostável, com EVA, polímero de origem petroquímica e não biocompostável, são altamente dependentes do número de fases constituintes do sistema, esse trabalho investigou inicialmente a miscibilidade desses blendas. Assim, blendas contendo entre 10 e 90% (m/m) de EVA foram preparadas a partir do estado fundido em reômetro de torque e caracterizadas por calorimetria exploratória diferencial (DSC) e microscopia eletrônica de varredura (MEV). Os resultados da reometria de torque indicaram que o EVA65 sofreu degradação termomecânica (com ramificação e/ou reticulação das cadeias), enquanto que no PHBV predominou o processo de cisão. As blendas PHBV/EVA65 apresentaram duas transições vítreas e nítida separação de fases, em todas as composições, típicas de sistemas imiscíveis. Em contraste, o EVA90 não apresentou degradação nas condições de estudo. As curvas DSC das blendas PHBV/EVA90 apresentaram uma única temperatura de transição vítrea (Tg) cuja variação em função da fração em massa de cada componente foi prevista pela equação de Fox. As micrografias indicando a presença de uma única fase comprovam que as blendas PHBV/EVA90 são totalmente miscíveis em qualquer proporção. Após essa etapa, buscou-se avaliar a influência do teor de VA nas blendas PHBV/EVA. Para atingir esse objetivo, blendas contendo 5, 10, 20 e 30% (m/m) de EVA foram preparadas em extrusora dupla rosca co-rotacional interpenetrante e a influência do teor de VA na biodegradabilidade, morfologia e comportamento térmico e mecânico dessas blendas foi investigada por ensaio de biodegradação em solo, MEV, DSC, análise termo-dinâmico mecânica (DMA) e, ensaios mecânicos de tração e impacto. Além da influência sobre as transições térmicas dos polímeros mencionada anteriormente, os resultados de DSC mostraram que a temperatura de cristalização a frio (Tcc) e a entalpia de fusão (ΔHm) do PHBV aumentaram com o aumento do teor de EVA. Porém, o teor de VA e, consequentemente a miscibilidade das blendas, teve forte influência sobre a entalpia de cristalização a frio (ΔHcc) do PHBV. A presença do EVA65 reduziu significativamente os valores de ΔHcc, enquanto para as blendas preparadas com EVA90 esses valores foram superiores ao do polímero puro, sugerindo influência direta sobre a cinética de cristalização do PHBV. De uma maneira geral, as propriedades mecânicas em tração, tais como, resistência à tração e módulo elástico diminuíram com o aumento do teor de EVA, independentemente do teor de VA nas blendas. Entretanto, a deformação na ruptura foi altamente influenciada pelo teor de VA. Blendas PHBV/EVA65 apresentaram pequeno aumento na deformação na ruptura com o aumento do teor de EVA, provavelmente devido à fraca adesão interfacial entre seus os componentes. Já a deformação na ruptura de blendas PHBV/EVA90 contendo 30% (m/m) de EVA foi de 280%, muito superior à deformação na ruptura de 1,7% do PHBV. A taxa de biodegradação das blendas PHBV/EVA foi menor que a determinada para o PHBV. Apesar da baixa perda de massa determinada no PHBV e nas blendas PHBV/EVA após 180 dias de ensaio de biodegradação, foi possível observar que blendas PHBV/EVA65 apresentaram taxas de biodegradação superiores as apresentadas pelas blendas PHBV/EVA90. Além disso, blendas PHBV/EVA65 contendo altos teores de EVA apresentaram maiores taxas de biodegradação. Nas blendas PHBV/EVA90 as maiores taxas de biodegradação foram obtidas em composições contendo baixos teores de EVA. Esses resultados demonstraram que a miscibilidade afetou a biodegradabilidade das blendas PHBV/EVA de maneira negativa. / The aim of this work was to develop and characterize blends of poly (hydroxybutyrateco-hydroxyvalerate) (PHBV) and poly (ethylene-co-vinyl acetate) (EVA) containing high amount of vinyl acetate (VA). The VA amount in the EVA used here were 65% (EVA65) and 90% (EVA90) in mass. As the final properties of PHBV blends, a polymer derived from a renewable and biocompostable source with EVA, a polymer of petrochemical and non-biocompostable origin, are highly dependent on the number of constituent phases of the system. Therefore this work initially investigated the miscibility of these blends. PHBV/EVA blends containing 10 to 90% (m/m) of EVA were prepared from the molten state in a torque rheometer and characterized by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results of the torque rheometry indicated that EVA65 chains underwent thermomechanical degradation with branching and / or crosslinking, while in PHBV the scission process predominated. The PHBV/EVA65 blends presented two vitreous transitions and distinct phase separation, typical of immiscible systems. In contrast, EVA90 showed no degradation in the study conditions. The DSC curves of the PHBV/EVA90 blends presented a single glass transition temperature (Tg) whose variation as a function of the mass fraction of each component was predicted by the Fox equation. The micrographs indicating the presence of a single phase prove that PHBV blends/EVA90 are totally miscible in any proportion. After this step, the influence of VA amount on the PHBV/EVA blends was studied. PHBV/EVA blends containing 5, 10, 20 and 30% (m/m) EVA were prepared in an interpenetrating co-rotational double screw extruder and the influence of VA content on the biodegradability, morphology and thermal and mechanical behavior of these blends was investigated by soil biodegradation test, SEM, DSC, dynamic mechanical analysis (DMA) and mechanical tensile and impact tests. In addition to the influence on the thermal transitions aforementioned, the DSC results showed that the cold crystallization temperature (Tcc) and the melting enthalpy (ΔHm) of PHBV increased with increasing EVA amount. However, the VA content and hence the miscibility of the blends, had a remarkable influence on the cold crystallization enthalpy (ΔHcc) of PHBV. The presence of EVA65 significantly reduced ΔHcc values, while for blends prepared with EVA90 these values were higher than that of pure polymer, suggesting a direct influence on PHBV crystallization kinetics. In general, mechanical tensile properties, such as tensile strength and elastic modulus decreased with increasing EVA content, regardless of the VA content in the blends. However, the deformation at rupture was highly influenced by the VA amount. PHBV/EVA65 blends exhibited small increase in the elongation at break with increasing EVA amount, probably due to the poor interfacial adhesion between their components. The elongation at break of PHBV/EVA90 blends containing 30% (m/m) of EVA was 280%, much higher than the elongation at break of 1.7% of neat PHBV. The biodegradation rate of PHBV/EVA blends was lower than that determined for PHBV. Despite the low loss of mass determined in PHBV and PHBV/EVA blends after 180 days of biodegradation test, it was possible to observe that PHBV/EVA65 blends had higher biodegradation rates than PHBV/EVA blends90. In addition, PHBV/EVA65 blends containing high EVA amount showed higher rates of biodegradation. In the PHBV/EVA90 blends the highest rates of biodegradation were obtained in compositions containing low EVA contents. These results demonstrated that the miscibility affected the biodegradability of PHBV/EVA blends negatively.

L’incorporation de nanoplaquettes d’argile dans une matrice ou un mélange de thermoplastiques s’avère prometteur pour en améliorer les propriétés d’usage. Récemment, un procédé de synthèse hydrothermale a permis d’obtenir un hydrogel chargé de nanoplaquettes de talc, ouvrant des perspectives d’élaboration de nanomatériaux à base de talc, potentiellement concurrents de ceux à base d’argile modifié. La grande quantité d’eau, introduite dans les appareils de mise en œuvre à l’état fondu, conduit à une perte de matière minérale importante et à l’agrégation partielle du talc. Ces contraintes rendent obligatoire l’utilisation de la mini-extrudeuse, de faible capacité, pour élaborer ces systèmes multiphasiques innovants, comme les nanocomposites polyamide/talc synthétique ou les mélanges polypropylène/polyamide (PP/PA) chargés de talc synthétique. Dans une phase polaire, le talc synthétique présente une structure constituée majoritairement de nanoparticules, mais aussi d’agrégats formés lors du malaxage. Il a été montré qu’une polarité accrue de la phase polyamide facilitait la nanodispersion du talc synthétique. Dans le cas des mélanges chargés, le talc synthétique est préférentiellement localisé dans les nodules de PA. Pour un polyamide peu polaire, l’effet émulsifiant est amplifié, ce qui s’explique par la rupture des nodules au niveau de zones peu cohésives PA/talc synthétique. D’autre part, l’augmentation de la viscosité de la matrice PP entraîne une localisation partielle du talc synthétique à l’interface matrice/nodules.Les relations structure-rhéologie des systèmes binaires et ternaires ont été discutées. / Addition of clay nanoplatelets within a thermoplastic matrix or immiscible thermoplastic blend usually improves final properties of materials. Recently, a hydrogel containing talc nanoplatelets has been obtained from hydrothermal synthesis, opening possibilities of development of talc based nanomaterials, which could rival the nanocomposites based on organically modified clay.The presence of large amount of water in the mixing chamber leads to significant losses of inorganic matter and to the presence of a few synthetic talc aggregates. These observations require the use of a twin screw mini-extruder which is appropriate to the elaboration of innovative multiphase materials, such as the synthetic talc/polyamide nanocomposites or the synthetic talc/polyamide/polypropylene blends.The structure of nanocomposites based on synthetic talc is mainly composed of nanometric entities, but also of a few micrometric aggregates. It has been shown that an increase of the polarity of the polyamide favours the dispersion of synthetic talc at nanometric scale.In the case of filled blends, the synthetic talc particles are preferentially located within PA nodules. The reduction of nodule size is explained by the breakup of nodules, due to numerous cohesion defects between synthetic talc nanoparticles and polyamide dispersed phase. Moreover, increasing polypropylene matrix viscosity leads to a selective localization of the synthetic talc at the nodule/matrix interface.Relationships between structure and rheology of binary and ternary systems have been discussed.

O Poli (ácido lático), PLA, e a Policaprolactona, PCL, são dois poliésteres termoplásticos alifáticos, conhecidos por suas capacidades de biodegradabilidade e bioreabsoção e, nos últimos anos, têm sido amplamente estudados como alternativas aos metais em bioimplantes. Por terem características mecânicas distintas, muitas vezes estes materiais são utilizados em blendas poliméricas, visando obter uma combinação construtiva entre tais propriedades; o PLA é mais rígido, tem maior resistência à tração, contudo é frágil; o PCL tem menor rigidez, contudo apresenta maior tenacidade, além de ser extremamente dúctil. A combinação destas propriedades em uma blenda torna a dupla PLA/PCL especialmente atraente à utilização em stents coronarianos, no qual o uso do PLA como único componente do stent pode causar complicações ao paciente, devido à necessidade de aquecimento do material acima de sua temperatura de transição vítrea (ao redor dos 60°C) para que ele possa ser inflado sem risco de uma catastrófica falha. Entretanto, tal aquecimento pode causar necrose dos tecidos coronarianos. Assim sendo, a inclusão do PCL na blenda tem como principal objetivo diminuir a temperatura de transição vítrea do conjunto do PLA. Este estudo teve como principal foco a análise de como o acréscimo de PCL e de dois diferentes tipos de compatibilizantes impactou no comportamento térmico e mecânico das blendas. Para tal, testes dos vinte tipos de blendas desenvolvidas foram submetidos a análises de DSC, DMTA e a ensaios de tração e impacto. Os últimos dois são de fundamental importância, pois o PLA tem pouca ductilidade e resistência ao impacto. Além desses testes, foram efetuadas também análises MEV, com intuito de verificar as modificações morfológicas das blendas ao adicionar-se tanto os compatibilizantes, quanto PCL às formulações. Ensaios espectroscópicos na região do infravermelho também foram conduzidos, a fim de analisar-se, além das estruturas químicas dos componentes da blenda, as interações entre eles e as modificações espectrais causadas por ela. Testes preliminares, como o GPC e a termogravimetria, também estão presentes. Com isso foi possível, além de fazer a determinação da massa molar dos componentes da blenda, ter acesso a dados acerca da degradação térmica dos polímeros utilizados. Ademais, a fim de analisar-se preliminarmente o potencial das blendas desenvolvidas como biomaterial, foram efetuados testes de Citotoxidade em formulações selecionadas. Como resultado da intensa investigação sobre as propriedades das blendas PLA/PCL, compatibilizadas ou não, foi verificado grande aumento de ductilidade nas formulações, sem perda apreciável de resistência mecânica. Em muitas das blendas, houve também expressivo aumento na tenacidade. Em contrapartida, não foram verificadas alterações significativas no perfil térmico das amostras, conforme DMTA e DSC. / The Polylactide, PLA, and the Polycaprolactone, PCL, are two thermoplastic aliphatic polyesters, known for their biodegradability and bioresorption abilities and, in the latest years, they have been extensively studied as alternatives to metals in bioimplants. Since they have distinct mechanical properties, these materials are many times used in polymeric blends, in order to obtain a constructive combination of the mechanical properties; the Polylactide is more rigid and has better tensile resistance, however it is brittle; on the other hand, the Polycaprolactone has lower rigidity, but it has better toughness, in addition to its great ductility. The combination of these properties in a blend makes the PLA/PCL configuration especially attractive to the use in coronary stents, on which the use of the PLA as only component may cause serious complications to the patient, due to its need to be warmed above its glass transition temperature (around 60°C) in order to be inflated without the risk of any catastrophic failure. However, this heating might cause necrosis of the coronary tissue. The inclusion of the PCL on the blend has, as a main goal, the objective of, in addition to lowering the glass transition temperature on the aggregate, is to allow the expansion of the material with no risk of failure. This study focused on how the addition of PCL and two different kinds of compatibilizers alters the thermal and mechanical behavior of the blends. To do so, tests were performed on the twenty types of blends developed, e.g. DSC, DMTA, tensile and impact tests. The latter two are of critical importance, because the Polylactide has little toughness and ductility. Furthermore, SEM was also performed in order to verify the morphological changes caused by increasing the PCL concentration on the blends, as well as the addition of the compatibilizers. Infrared spectroscopic analysis was also conducted on the blends, thus the chemical structures of the main components of the blends could be assessed, as well as the interactions and the spectral changes caused by it. Preliminary tests, for example, GPC and thermogravimetry were also conducted. With this data, it was possible to determine the molar mass of the blends components and assess the thermal degradation profile of the materials used. Moreover, preliminary tests were conducted in order to determine the potential some selected blends have as biomaterials. As the result of this deep research on the PLA/PCL blends properties, compatibilized or not, it was possible to achieve relevant increase in the ductility and toughness of the formulations, with no significant loss in terms of mechanical resistance. On the other hand, no significant changes on the thermal profile of the blends were observed, according to DMTA and DSC tests.

A obtenção de blendas condutoras a base de água, ainda é pouco explorada e apresenta uma interessante alternativa ao uso de compostos poluentes como os cromatos na proteção à corrosão metálica. Os polímeros condutores apresentam propriedades anti-corrosivas e podem ser processados em meio aquoso, eliminando o uso de solventes orgânicos altamente tóxicos e agressivos para o meio ambiente. O presente trabalho consiste no estudo da proteção da corrosão metálica por revestimento de filmes de blendas contendo Poli(anilina) (PANI). As blendas foram obtidas à partir da mistura de uma suspensão aquosa de PANI com uma dispersão aquosa de Poli(metil metacrilato). O uso de técnicas como potencial zeta, espalhamento de luz dinâmico, análise térmica e microscopia eletrônica de varredura permitiram a caracterização da mistura homogênea obtida. Medidas através do método da sonda de quatro pontas mostraram que as blendas apresentam condutividade mesmo com baixas quantidades de PANI e a técnica de espectroscopia Raman mostrou a presença da forma condutora deste polímero nos filmes das blendas. Técnicas como microscopia óptica, potencial a circuito aberto, voltametria linear e espectroscopia de impedância eletroquímica permitiram avaliar a proteção à corrosão de eletrodos metálicos de ferro, cobre e níquel recobertos com filmes das blendas de PANI em diferentes meios corrosivos. As blendas mostraram eficiência contra a corrosão e apresentam-se como um novo material não poluente para a proteção à corrosão metálica. / The development of water-based conducting blends has not yet been very much explored and it presents itself as an interesting alternative to the use of polluting compounds such as chromates in the protection of metals from corrosion. The conducting polymers present anti-corrosion properties and can be processed in aqueous medium, eliminating the use of organic solvents, which are highly toxic and threatening to the environment. This thesis is based on the study of protection from metallic corrosion using poly(aniline) (PANI) coating blends. The blends have been obtained by mixing a PANI aqueous suspension with a poly(methyl metacrylate) aqueous dispersion. Techniques such as zeta potential, dynamic light scattering, thermal analysis and scanning electronic microscopy allowed the characterization of the homogeneous mixture obtained. Measurements carried out by the four-point probe method showed that the blends present conductivity even despite low PANI quantities. In addition, the Raman spectroscopy technique showed the presence of the conducting form of this polymer on the blend films. Techniques such as optical microscopy, open-circuit potential, linear voltammetry and impedance spectroscopy allowed the evaluation of the corrosion protection of the iron, copper, and nickel metallic electrodes coated with PANI blend films in different corrosives mediums. The blends showed efficiency against corrosion and they are therefore a new environmentally friendly material for metallic corrosion protection.

Este trabalho tem como objetivos a preparação e a caracterização de blendas de amido termoplástico e borracha natural, obtidos a partir dos amidos de mandioca e milho e do látex de borracha natural utilizado diretamente como extraído da seringueira, sem nenhum tipo de tratamento prévio. Os amidos termoplásticos (TPS) foram processados em misturador intensivo em duas temperaturas diferentes (120oC e 150oC), utilizando como plasticizantes a glicerina, o etilenoglicol e o propilenoglicol na proporção de 30 % em massa na matriz, e teores de látex de borracha natural (NRL) variando na proporção de 2,5 a 10 % em massa na blenda. As propriedades das blendas foram avaliadas por difração de Raios-X, por termogravimetria (TG), ensaios mecânicos de resistência à tração, por ensaios de absorção de água e por microscopia eletrônica de varredura (SEM). O cisalhamento desenvolvido durante o processamento em misturador intensivo levou à perda da estrutura cristalina e à desestruturação dos grânulos de amido. A adição de látex diminuiu os valores de índice de cristalinidade dos TPS, não alterando, entretanto, o comportamento cristalográfico com relação ao tipo de padrão de cristalinidade apresentado pelos TPS. Com relação à estabilidade térmica, os TPS mostraram-se dependentes da fonte de amido utilizado, do tipo de plasticizante, da temperatura de processamento e do teor de látex presente. Quanto à resistência mecânica, o TPS de milho se mostrou mais resistente que o de mandioca, principalmente quando plasticizado com glicerina, tendo a temperatura de processamento pouca influência sobre os resultados. Com relação aos teores de látex adicionados, não foi observada nenhuma melhora significativa sobre a resistência mecânica dos TPS, exceto um pequeno aumento nos valores de alongamento à ruptura. A adição de látex proporcionou uma diminuição linear na absorção máxima de água no equilíbrio, assim como uma redução nos valores de coeficiente de difusão de água apresentado pelos TPS. Uma vez que o processo de mistura desempenha uma função importante na morfologia destas blendas, na maioria dos TPS plasticizados com glicerina, entretanto, para os TPS plasticizados com etilenoglicol e com propilenoglicol não houve uma boa dispersão dos componentes das misturas. Os TPS de milho plasticizados com glicerina à 150oC foram os que apresentaram uma melhor dispersão das partículas de látex quando comparado com os demais. A qualidade destas dispersões foi uma conseqüência da utilização do látex ao invés da borracha sólida, uma vez que o primeiro apresenta a presença de proteínas e lipídeos na superfície das partículas de borracha presentes no látex, atuando como um compatibilizante entre o amido, uma matriz polar, e a borracha, um material não-polar. / The aim of the study reported here was to prepare and characterize blends of thermoplastic starch and natural rubber, based on manioc starch (tapioca), corn starch and natural rubber latex used directly as extracted from Hevea brasiliensis (Brazilian rubber tree), without prior treatment. The thermoplastic starch (TPS) matrices were prepared in a high-intensity mixer at two temperatures (120°C and 150°C), with 30% (w/w) glycerol, ethylene glycol or propylene glycol as plasticizer, and from 2.5% to 10% (w/w) natural rubber latex (NRL) was added to form the blends. The properties of the composite blends were assessed by XRD, TGA, tensile strength tests, water absorption tests and SEM. The shearing forces developed during mixing resulted in a loss of crystallinity and breakdown of the starch granule structure. The addition of NRL reduced the crystallinity index of the TPS, but did not change the type of crystal structure exhibited by this phase. The thermal stability of the TPS matrix was found to depend on the origin of the starch, the type of plasticizer, the processing temperature and the latex content. In the mechanical strength tests, the cornstarch TPS proved stronger than the manioc product, especially when plasticized with glycerol, while the mixing temperature had little influence. With the addition of NRL, no significant was observed in the mechanical properties, except for a small increase in the elongation of the material at breakpoint. As latex was added there was a linear decrease in the maximum absorption of water at equilibrium, as well as a reduction in the diffusion coefficient of water in the matrix. While the mixing process played an important part in producing an adequate blend morphology in most of the mixtures containing glycerol, the components of blends in which the TPS was plasticized with ethylene or propylene glycol were not well-dispersed. The TPS that afforded the best dispersion of latex particles was composed of cornstarch and glycerol and plasticized at 150°C. The highquality dispersion achieved was a consequence of using raw latex instead of solid rubber, since in the latex the rubber particles are coated with surface proteins and lipids that help to compatibilize the starch, a polar matrix, with the nonpolar rubber.

Different methods for quality assessment of separated andcommingled plastics from household and electronic waste havebeen developed. Especial attention has been given tospectroscopic methods since they are non-destructive andrequire little or no sample preparation at all. A wide variety of low molecular weight compounds have beenidentified in recycled polyethylene (HDPE) and polypropylenefrom hard packaging waste by gas chromatography- massspectroscopy (GC-MS) after microwave assisted extraction (MAE).Low molecular weight substances such as alcohols, esters,ketones and fragrance and flavour compounds were detected inthe recycled resins. The major category of compounds identifiedin the virgin resins is conformed by aliphatic hydrocarbonssuch as alkanes and alkenes. It was found that theconcentration of aromatic hydrocarbons without functionalgroups, e.g. ethylbenzene and xylenes in recycled HDPE wasapprox. 5 times higher and equal to 120 and 35 ppb,respectively. The potential of near infrared (NIR) and Fourier transformRaman (FT-Raman) spectroscopy in combination with multivariateanalysis as a rapid, non-destructive and accurate analyticalmethod has been studied and the feasibility of these methodsfor at/in line characterisation of several properties ofrecyclates has also been explored. NIR in diffuse reflectance mode has been successfully usedfor quantification of antioxidants in polyethylene, thestandard error of prediction is almost comparable to the errorof wet methods, i.e., extraction plus liquid chromatography.The error of prediction of this method is 35 ppm for Irganox1010 and 68 ppm for Irgafos 168. The inaccuracy in thequantification of Irgafos 168 is due to the fact that thisantioxidant degrades during polymer processing. NIR and Mid-infrared (Mid-IR) worked well for fastdetermination of molecular weight and crystallinity of therecycled HDPE and acceptable errors of prediction, comparableto that of the reference methods, i.e. size exclusionchromatography (SEC) and differential scanning calorimetry(DSC) have been obtained. The present thesis also shows that NIR and Raman are goodcandidates for in/on line compositional analysis of mixedpolymer fractions from recycled plastic waste. Diffusereflectance NIR allows a rapid and reliable measurement ofpellets and requires no previous sample preparation. Thecomposition of binary blends can be determined with highaccuracy. The PP content in the PP/HDPE blends was predictedwith a RMSEP equal to 0.46 %w in the 0-15 %wt region and theRMSEP for PP in the PP/ABS blends was 0.3 %wt. The thermal and thermoxidative stability of recycled PP,HDPE and a 20/80 PP/HDPE blend subjected to multiple extrusionhave been studied by DSC, thermal analysis (TGA) andchemiluminiscence (CL). A decrease in Toxand OIT was observed after each extrusion step.The drop in OIT was sharper after the first two extrusions. TheOIT values produced by DSC and CL were in good agreement.However, CL provided more information about the oxidationprocess taking place in the blends. The moisture content in recycled polyamide 6,6 was readilydetermined by NIR in transmission mode and it could bepredicted with a RMSEP = 0.05 %wt. The accuracy of the methodappeared to be as good as that of the more time consumingthermal methods such as TGA, DSC and loss on dry (LOD), whichwere used as reference methods. The influence of differentamounts of water on the viscoelastic properties of nylon hasbeen investigated. <b>Keywords:</b>Recycling, HDPE, PP, blends, nylon 6,6, ABS,water content, MAE, GC-MS, NIR, FT-Raman, chemiluminiscence,low molecular weight compounds, antioxidant content,crystallinity, molecular weight, thermal stability,characterisation methods, analysis of polymers, blends.

The influence of supplementary materials such as slag, metakaolin and limestone in steam-cured ternary and quaternary cement blends on physical and chemical hydration mechanisms was studied by analyzing the evolution of non-evaporable water content, hydration products and compressive strength. The role of limestone in hydration reactions of cement was also investigated. These properties were studied through the use of differential thermal and thermogravimetric analyses, as well as the loss-on-ignition, X-ray diffraction and compressive strength tests at 1, 3, 7, and 28 days. Research findings revealed that it is possible to replace up to 40% cement with other materials and still achieve compressive strengths similar to mixtures with a 25% cement replacement at 0.34 w/b ratio. Additionally, ternary limestone mixtures exhibited superior mechanical properties to ternary metakaolin mixtures. Lastly, limestone powder was determined to behave as inert filler, accelerating hydration at early ages through heterogeneous nucleation.

The influence of supplementary materials such as slag, metakaolin and limestone in steam-cured ternary and quaternary cement blends on physical and chemical hydration mechanisms was studied by analyzing the evolution of non-evaporable water content, hydration products and compressive strength. The role of limestone in hydration reactions of cement was also investigated. These properties were studied through the use of differential thermal and thermogravimetric analyses, as well as the loss-on-ignition, X-ray diffraction and compressive strength tests at 1, 3, 7, and 28 days. Research findings revealed that it is possible to replace up to 40% cement with other materials and still achieve compressive strengths similar to mixtures with a 25% cement replacement at 0.34 w/b ratio. Additionally, ternary limestone mixtures exhibited superior mechanical properties to ternary metakaolin mixtures. Lastly, limestone powder was determined to behave as inert filler, accelerating hydration at early ages through heterogeneous nucleation.

As space exploration has advanced, time spent in space has increased. With the building of the International Space Station and plans for exploration missions to the Moon and Mars, astronauts will be staying in space for longer periods of time. With these increased stays in space comes an increase in fire safety concerns. One area of fire safety interest is flammability. While current flammability test procedures are in place, they are all performed on the ground and may not be representative of flammability in microgravity. In addition to this, limited research into the severity of skin burn injury in a microgravity environment has been performed. <p>An apparatus was designed to be flown on a low gravity parabolic aircraft flight to assess the flammability of cotton and 50% cotton/50% polyester fabrics and the resulting skin burn injury that would occur if these fabrics were to ignite. The apparatus, modelled after a Canadian General Standards Board standard flammability test, was also used on the ground for experiments in 1-g. Variables examined in the tests include gravity level, fabric type, air gap size, oxygen concentration, apparatus orientation, ignition source, and method used to secure the specimen. Flame spread rates, heat fluxes, and skin burn predictions determined from test results were compared. <p>Results from test in 1-g indicated that the orientation of the apparatus had a large effect on flame spread rate, heat flux and predicted skin burn times. Flame spread rates and heat fluxes were highest when the fabric was held in the vertical orientation, which resulted in the lowest predicted times to produce skin burns. Flame spread rates and heat fluxes were considerably lower in microgravity than in 1-g, which resulted in higher predicted times to produce skin burns.

As space exploration has advanced, time spent in space has increased. With the building of the International Space Station and plans for exploration missions to the Moon and Mars, astronauts will be staying in space for longer periods of time. With these increased stays in space comes an increase in fire safety concerns. One area of fire safety interest is flammability. While current flammability test procedures are in place, they are all performed on the ground and may not be representative of flammability in microgravity. In addition to this, limited research into the severity of skin burn injury in a microgravity environment has been performed. <p>An apparatus was designed to be flown on a low gravity parabolic aircraft flight to assess the flammability of cotton and 50% cotton/50% polyester fabrics and the resulting skin burn injury that would occur if these fabrics were to ignite. The apparatus, modelled after a Canadian General Standards Board standard flammability test, was also used on the ground for experiments in 1-g. Variables examined in the tests include gravity level, fabric type, air gap size, oxygen concentration, apparatus orientation, ignition source, and method used to secure the specimen. Flame spread rates, heat fluxes, and skin burn predictions determined from test results were compared. <p>Results from test in 1-g indicated that the orientation of the apparatus had a large effect on flame spread rate, heat flux and predicted skin burn times. Flame spread rates and heat fluxes were highest when the fabric was held in the vertical orientation, which resulted in the lowest predicted times to produce skin burns. Flame spread rates and heat fluxes were considerably lower in microgravity than in 1-g, which resulted in higher predicted times to produce skin burns.