Four denture base materials of poly(methyl methacrylate) (QC-20, Pladent-20, Hygenic, and Optilon-399) were prepared by convention water bath and microwave-energy cured methods. While the resin was in the dough stage, it was packed into two molds (65 mm ¡¦15 mm ¡¦10 mm) in the fiber reinforced plastic flask. The variation of temperature with time was recorded by two thermocouples during the microwave heating at 80, 160, and 240 watts, respectively. Microwave polymerization was carried out in the same equipment. The microwave flask containing the same size of resin blocks were processed at 80, 160, 240, and 560 watts for 15, 10, 7, and 2 min, separately. Then each flask was turned over, and cured an additional 2 min at 560 watts. In the case of water-bath method, the resin in the dough stage was packed in the Brass flask, and then cured at 70¢J for 9 hours. Ten specimens were prepared for each condition studied. The surface hardness, porosity, flexural properties and solubility of both process conditions were evaluated. The samples were sectioned by microtome and stained 2 % Osmiun tetroxide, then the morphology of Optilon-399 was observed by using TEM (Transmission electron microscopy) at 160 KV. The result indicate that the flexural strength for Optilon-399 specimens prepared by water-bath method was 20 MPa higher than that prepared in microwave oven, however, there were no obvious difference between the samples cured at different power. Phase separation in two different sizes was observed in all of the Optilon-399 specimens. The larger domain was with 0.18 mm~0.67 mm diameter has dispersed rubber phase surrounded by a rubber periphery. The smaller domain with 0.1 mm diameter is rich with rubber phase. The size and distribution of the larger domain were correlated with the microwave power and curing time. The sample cured by water-bath has the largest average domain diameter (0.395¡Ó0.068 mm). In the specimens prepared by microwave method, the domain size decreased with increasing power. In additions, the domain size varied across the specimen. The size difference between the largest and the smallest domain for specimens cured at 80W was 0.03 mm, and that for specimens cured at 560W was 0.05 mm. This indicated that the larger the power watt was, the higher the morphology difference was.

Nanostructures and properties of blends of homopolymer and elastomeric block copolymer nanoparticles were studied focusing on the effect of morphology and the viscoelastic properties on blends. The cylindrical and lamellar morphology of PS-b-PI copolymer was employed to generate the morphology of elastomeric nanoparticles such as nanofiber and nanosheet. The particles were synthesized using cold vulcanization process. The vulcanization process using sulfur monochloride (S2Cl2) was used to preserve the morphologies. The crosslinking density of block copolymer was controlled by exposure time of crosslinking agent in the chamber. The blend samples for DMA and rheometer were prepared using solvent casting process. The diameter and thickness of nanofiber and nanosheet obtained by the process were ~40 nm and ~70 nm, respectively. The rheological and dynamic mechanical properties of the blends of polystyrene (PS) and elastomeric nanoparticles were studied in terms of morphology and crosslinking density. The effect of core PI size also investigated and discussed. Based on these viscoelastic results, the theoretical percolation threshold was calculated and compared with experimental results. It is demonstrated that block copolymer is a facile method to generate elastomeric nanoparticles using cold vulcanization and viscoelastic properties can be tuned with addition of nanoparticles.

This research project has investigated the mechanical properties and behaviour of third generation synthetic turf surfaces used for football and rugby, with a focus on the traction behaviour produced at the shoe-surface interface. The physical characteristics and mechanical properties of the component materials used in the construction of third generation surfaces were examined. The bulk density of the rubber infill material was found to be a key variable. This was shown to be influenced by compaction and the resulting compression of the rubber infill material under an applied load. Increasing the compactive effort and/or compression under loading increased the bulk density. Shear strength of the rubber infill material was shown to be influenced by bulk density, increasing with a higher bulk density. The composite surface system behaviour of third generation synthetic turf surfaces was investigated. Several surface variables were measured including; shockpad thickness, synthetic turf carpet construction, infill thickness, infill bulk density and infill material type. Shockpad thickness, rubber infill thickness and bulk density were found to influence the impact behaviour, with a thicker rubber layer (shockpad and/or rubber infill layer) reducing the hardness of a surface system. Increasing the bulk density of the rubber infill with compactive effort increased the surface system hardness. Traction behaviour of composite surface systems was explored using three traction test methods to measure both rotational and translational traction. Rubber infill bulk density was shown to be a primary influencing variable from the playing surface variables investigated. Several further traction variables were explored to provide a fuller understanding of the mechanisms involved in the production of traction at the shoe-surface interface including; vertical stress, stud configuration, stud dimension, stud penetration, water and temperature. Vertical stress and stud configuration were found to be primary variables influencing traction development. A traction framework has been developed identifying the factors affecting the production of traction at the shoe-surface interface. It is intended that the traction framework can be used by the sports surface industry, sports governing bodies and academia to aid in the decisions and judgements made during the design, construction and maintenance of these surfaces to obtain desired characteristics and optimise performance and safety.

This thesis identified key mix design variables that influence the mechanical properties and behaviour of shockpads and developed a mechanical model to describe this behaviour. This investigation was undertaken to address the lack of scientific understanding of shockpad layers used in synthetic sports pitches. Shockpads play a crucial role in the player and ball interaction properties of synthetic pitches. However, the current poor state of knowledge regarding shockpad mix design effects and the implications for site practice during construction was developed through constructor experience and basic testing. This lack of comprehensive knowledge was reflected in the barelyexistent standards for design specification and testing requirements stipulated by sporting governing bodies at the time of this project inception. Further scientific investigation of the effects of shockpad mix design on mechanical properties and behaviour was required to develop guidelines to optimise shockpad design, construction and testing and also to build more knowledge on sport surface behaviour due to growing interest among the industry and other stakeholders such as governing bodies and sport shoe manufacturers for example. A method to construct small-scale cast in-situ shockpads in the laboratory was developed to produce reliable and repeatable samples for investigation, including a benchmark shockpad and shockpads with carefully controlled mix design variations. Shockpad thickness, binder content, binder type, rubber size, rubber size distribution and bulk density were varied through a range of appropriate values in the laboratory constructed shockpads. Shockpads and shockpad-carpet systems (using water based and 3'1 generation carpets) were subjected to Berlin Artificial Athlete and 2.25 kg Clegg Hammer impacts to measure player-surface interaction properties and vertical hockey ball impacts to measure ball interaction properties. Tensile measurements and cyclic fatigue testing were used to determine shockpad durability. Impact testing was repeated on shockpads and shockpad-carpet systems with thickness variations to determine shockpad behaviour using a force plate. Behaviour measurements were used to develop a mechanical model to describe shockpad behaviour. (Continues...).

The aim of this thesis is to investigate the effects of Mn content and alloying additions such as Cr and Mo, and various heat treatment procedures on both microstructure and mechanical properties of austenitic manganese (Hadfield) steels. For this purpose, steels with two different Mn content were considered (12-14 Mn, 16-18 Mn). First, five different heat treatment procedures were applied to the as-cast 12-14 Mn specimens to decide the procedure resulting the optimum tensile properties. Then, the specimens having various amounts of Mn, Cr and Mo were cast and heat-treated to investigate the effect of alloy modifications on austenitic manganese steels. Optical and scanning electron microscopies were used for microstructural investigation. To determine the mechanical properties, tensile tests and hardness tests were carried out. In addition to correlation between microstructure and mechanical properties, ultrasonic velocity measurements were also done. The results show that both composition and heat treatment affect the performance of hadfield steels extensively, and these changes also affect the propogation velocity of the ultrasonic waves.

Les procédés de dépôt de couches minces optiques par voie physique ou par voie sol-gel présentent par nature des limitations pour la réalisation de revêtements épais (>1 µm) et ont alors recours à des empilements multicouches pour la préparation de miroirs diélectriques ou de polariseurs. C'est pour ces raisons qu'il est intéressant d'étudier les conditions permettant d'augmenter l'épaisseur critique des films sol-gel notamment. Après avoir étudié la capacité d'empilements des couches colloïdales, trois principaux paramètres ont été identifiés permettant d'augmenter l'épaisseur critique d'empilements monomatériaux et multimatériaux. Ces paramètres sont : l'épaisseur déposée,les interactions chimiques entre les particules et le temps de séchage du film. Ils influencent la microstructure des empilements et par conséquent les propriétés optiques et mécaniques. En contrôlant tous ces paramètres, nous avons montré qu'il est possible de préparer des empilements colloïdaux de fortes épaisseurs ouvrent la voie à la préparation sol-gel de miroirs de hautes performances et/ou de polariseurs. En outre, un développement spécifique de méthodes de caractérisations optiques et mécaniques a été nécessaire pour l'étude de ces films sol-gel, à la fois minces et fragiles. / Main optical deposition processes, physical vapor deposition or sol-gel, exhibit difficulties of achieving thick coatings (>1 µm) and to build multilayer stacks (dielectric mirrors, polarizers). For these reasons, we have studied the conditions to enable a significative increase of deposited sol-gel films thickness. Three main parameters have been evidenced enabling the control of the stacking ability : single layer deposited thickness, chemical interactions beetween nanoparticles and coating drying time. We have shown that these parameters depend on the sol composition and on deposition conditions (process) and that the microstructure of single material stacking is influenced. Optical and mechanical properties of sol-gel films have been studied and optimized regarding these different material and process parameters. For this reason, optical and mechanical characterization techniques have been specifically developed and can now be used for fragile and thin film characterization. In controlling all these parameters, it is now possible to prepare multilayer colloidal stack with high thicknesses enabling the fabrication of high-performance mirrors and polarizers.

Doctor of Philosophy / Department of Biological and Agricultural Engineering / Donghai Wang / The depletion of petroleum feedstock along with significant concerns about health and environment lead to an interest in alternative green products. Soy protein (SP) adhesives have great potential as a renewable material for wood industries. The obstacle of applying SP-based adhesives is its relatively low water resistance. The overall objective was to enhance the water resistance of SP adhesives through protein and lignin interaction. An improvement of adhesion performance, flowability, and thermal properties of SP adhesives was achieved through the protein and lignin interaction and formation of protein and lignin copolymer. pH adjustment is a simple process to change protein folding and lignin properties. Cleavage of β-O-4 linkage was observed at pH 8.5 and pH 12, resulting in an increase in lignin active groups and the changes in lignin particle size and thermal properties. Cross-linking of protein with lignin took place via carbonyl, amino, and hydroxyl groups. Multiple-point and non-specific interactions between lignin and protein resulted in stronger lignin-protein networks and changes in properties, which improved wet adhesion strength of protein adhesives. In addition, lignin was depolymerized by laccase enzyme with the presence of mediator, TEMPO, to induce a formation of the strong lignin-protein network. The formation of the strong lignin-protein network increased the wet adhesion strength by 106% and the partial wood failure was observed after the three-layer wood test. A better performance was also observed on the three-cycle soaking test. The adhesion performance of SP adhesives was also greatly affected by lignin particle size and the protein to lignin ratio at pH 4.5. The wet adhesion strength of SP adhesives increased as lignin particle size decreased. The protein-lignin adhesive with protein to lignin ratio of 10:2 (w/w) at 12% solid content had the lowest contact angle and the highest wet adhesion strength of 4.66 MPa, which is 53.3% higher than that of 10% pure SP adhesive. Lignin-protein interactions, water resistance property, and glue line pattern had strong influences on an adhesion performance. Lignin and soy protein were modified at pH 4.5, 8.5 and 12. The maximum increase (620%) in water resistance was found at pH 12 with an addition of lignin. After the protein was unfolded (pH 8.5) and denatured (pH 12), it was refolded by shifting pH to 4.5. The better-wet adhesion performance was obtained at pH 4.5, 8.5-4.5 and 12 with rigid glue line. Shifting pH from 8.5 to 4.5 promoted lignin-protein interaction and increased adhesion performance. The protein-lignin adhesives using absolutely renewable materials and practical processes showed an excellent potential to replace the petroleum-based adhesives and fulfill the global demand for green products and technologies.

Neste presente trabalho foi realizado um estudo sobre copolímeros em bloco e seus nanocompósitos com diferentes estruturas morfológicas. Os polímeros estudados foram copolímeros de poliestireno-b-poli(etileno-co-butileno)-b-poliestireno (SEBS), sendo dois desses copolímeros com fração em massa de 30% de blocos de poliestireno (PS), e um deles modificado com anidrido maleico na fase de poli(etileno-co-butileno) (PEB). Os outros três copolímeros têm 13% de blocos de PS. A nanopartícula utilizada foi a argila montmorilonita organofílica Cloisite 20A. Os nanocompósitos foram preparados por dois métodos: i) mistura no estado fundido (extrusão); ii) solução. As microestruturas dos materiais resultantes foram caracterizadas pelas técnicas de espalhamento de raios X a baixo ângulo (SAXS) e difração de raios-X (DRX). As propriedades reológicas foram avaliadas em dois tipo de fluxo (cisalhamento e elongacional). Para avaliar as propriedades reológicas em fluxo de cisalhamento foram realizados ensaios de cisalhamento oscilatório em pequenas amplitudes (SAOS), cisalhamento oscilatório em grandes amplitudes (LAOS) e varredura de tempo (TS). Para avaliar as propriedades reológicas em fluxo elongacional foram realizados ensaios com geometria apropriada (SER), acoplada ao reômetro rotacional. Estes ensaios foram conduzindo em duas direções: paralela (longitudinal) e perpendicular (transversal) à direção do fluxo de extrusão. As análises de caracterização estrutural (DRX e SAXS) indicaram uma estrutura intercalada para os nanocompósitos SEBS/20A e esfoliada para as matrizes modificadas com anidrido maleico. A caracterização reológica dos copolímeros com 30% de blocos de PS em fluxo de cisalhamento mostrou que as morfologias dos nanocompósitos são estáveis com o tempo de cisalhamento, e permitiu confirmar as estruturas dos nanocompósitos. Para os copolímeros com 13% de blocos de PS foi possível identificar as temperaturas de transição ordem-ordem e ordem-desordem. Os resultados dos ensaios reológicos indicaram que ocorre alinhamento dos cilindros na direção dos fluxos de cisalhamento e elongacional. Também foram avaliadas as propriedades mecânicas, e os resultados mostraram que o comportamento mecânico é altamente influenciado pela estrutura morfológica e a incorporação de argila. / In this work block copolymers and their nanocomposites were studied. The polymers studied were copolymers of polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS), with two samples containing 30 wt% of PS blocks. The other three copolymers contained 13% of PS blocks. Two block copolymers are modified with maleic anhydride. The reinforcement used was the montmorillonite organoclay Cloisite 20A. The nanocomposites were prepared by two methods: i) melt blending (extrusion), with which a cylindrical hexagonal structure (anisotropic and isotropic) was obtained; ii) casting, with which a lamellar structure was obtained. The microstructures were characterized by the techniques of small angle X-ray scattering (SAXS) and X-ray diffraction (XRD). The rheological properties were evaluated in two different flows (shear and elongational). To evaluate the rheological properties in shear flow the samples were tested under small amplitude oscillatory shear (SAOS), large amplitude oscillatory shear (LAOS) and time sweep (TS). To evaluate the rheological properties in elongational flow, tests were carried out using an appropriate geometry (SER). The latter tests were conducted on samples aligned in two different directions: parallel (longitudinal) and perpendicular (transverse) to the flow direction of extrusion. The structural characterization analysis (XRD and SAXS) indicated an intercalated nanocomposite structure for SEBS/20A, and an exfoliated structure for the copolymers modified with maleic anhydride. The rheological characterization of the samples in shear flow showed that the morphologies of the nanocomposites are stable with time of shearing, and it confirmed the morphologies of the nanocomposites (30% PS block). For copolymers with 13 % of PS blocks it was possible to identify the order-order and order-disorder transition temperatures. The rheological tests showed that it is possible to align the morphologies in shear and elongational flows. The mechanical properties were also evaluated; the results have shown that the mechanical behavior was strongly influenced by the morphological structure and clay incorporation.

O Brasil e o terceiro maior produtor de mamona do mundo e o maior produtor da América do Sul. O óleo da mamona tem grande potencial na cadeia de produção de biodiesel, sendo interessante a geração de recursos dos subprodutos, como a torta de mamona. Apesar de ser rica em proteínas, a torta de mamona tem limitada aplicação em virtude da presença da ricina, que apresenta elevada toxidez. Assim, esperando-se valorizar esse subproduto com novas aplicações tecnológicas, o objetivo desta tese foi o desenvolvimento de filme biodegradável a partir da proteína extraída da torta de mamona. Especificamente, estudou-se o efeito do pH (10, 11 e 12) de extração das proteínas sobre algumas propriedades físicas (espessura, propriedades mecânicas, solubilidade em agua, permeabilidade ao vapor de agua e umidade) dos filmes produzidos. A partir da avaliação destes resultados, foi então definido o pH de extração da proteína da torta de mamona para o segundo estudo que envolveu a produção de filmes a base da proteína extraída da torta de mamona, reforçados com fibra de sisal e/ou glioxal. Primeiramente, as proteínas foram extraídas em um reator, adicionando-se 20% de torta de mamona na solução de NaOH (pH= 10, 11 e 12), com velocidade de agitação de 400 rpm e a 50ºC. A separação do extrato proteico do resíduo insolúvel foi feita por centrifugação (4.000 rpm). Os extratos foram liofilizados e submetidos a analises para determinação da composição centesimal e dos aminoácidos. Isotermas de sorção dessas proteínas foram determinadas a 25ºC. Os filmes foram produzidos por \"casting\", ou seja, pela desidratação de soluções filmogênicas com concentração constante de proteínas. No primeiro estudo, utilizou-se 7,5g de proteína/100g de solução filmogênica, agente reticulante glutaraldeido (0,8g de glutaraldeido/100g de proteína) e plastificante glicerol (25g de glicerol/100g de proteína). No segundo estudo, utilizou-se 6g de proteína/100g de solução filmogênica, agente reticulante glioxal (0,5g de glioxal/100g de proteína), fibra de sisal (20g de fibra/100g de proteína e plastificante glicerol (25g de glicerol/100g de proteína). Os filmes foram avaliados subjetiva e objetivamente, através da determinação da espessura, do brilho, dos parâmetros de cor e opacidade, da microestrutura, das propriedades mecânicas por testes de tração e perfuração, da umidade, da solubilidade em agua, da calorimetria diferencial de varredura, das isotermas de sorção e da espectroscopia por transformada de Fourier. Os extratos de proteínas liofilizadas foram ricos em proteínas (66-69%), em todos os pH estudados, sendo rico também em sais minerais (12-24%), possivelmente devido ao emprego de NaOH. Não se observou diferenças na composição de aminoácidos em função do pH de extração. No primeiro estudo, os filmes produzidos apresentaram-se com coloração amarronzada e com aspecto visual homogêneo, independentemente do pH de extração das proteínas. Observou-se que o pH de extração das proteínas influenciou as propriedades mecânicas dos filmes. O aumento do pH implicou em filmes mais resistentes a tração e a perfuração, cuja tensão na ruptura e a forca na perfuração foram 4,5 MPa e 6,5 N, respectivamente, para os filmes produzidos com proteínas extraídas no pH=12. Entretanto, independentemente das diferenças obtidas, esses filmes se mostraram pouco deformáveis, com elongação na ruptura e deformação na perfuração cerca de 1,5 e 3,2%, respectivamente. A solubilidade em agua também foi afetada pelo pH de extração das proteínas da torta de mamona. Enquanto o filme produzido com proteínas extraídas em pH=10 foi completamente solúvel em agua, os filmes de proteínas extraídas em pH=12 apresentaram solubilidade de 58,5%. A umidade dos filmes não dependeu do pH, ficando em torno de 13%. No segundo estudo, a adição da fibra de sisal na solução filmogênica tornou os filmes mais rugosos, sem mudanças visuais perceptíveis em função da presença de glioxal. A adição da fibra de sisal na formulação aumentou a espessura dos filmes de 0,11 para 0,16mm e diminuiu o brilho medido no angulo de 60º, a forca na perfuração de 11,2 para 9,1N, a deformação na perfuração de 5,7 para 2,4%, a tensão na ruptura de 10,3 para 5,1 MPa, a elongação na ruptura de 78,5 para 24,2% sem contudo alterar o modulo elástico dos filmes, que permaneceu em torno de 1,1-1,5 MPa. A solubilidade em agua dos filmes diminuiu de 42,8 para 36,8%, porem a umidade dos filmes não foi afetada, permanecendo em torno de 14%. A permeabilidade ao vapor de agua aumentou em cerca de 50%, passando de 0,6 para 1,2 g.mm/h.m2.kPa. Quanto aos parâmetros de cor, de modo geral, a adição das fibras causou um aumento da luminosidade (L*) e da opacidade, e diminuição dos cromas a* e b* e da diferença total de cor (ΔE*). Na calorimetria diferencial de varredura, a adição da fibra aumentou a temperatura de transição vítrea da fração rica em glicerol. Avaliando as isotermas de sorção, pode-se sugerir que a fibra influenciou na capacidade de absorção de agua dos filmes. Não foi possível detectar alterações nos espectros de FTIR em nenhuma das formulações produzidas, provocadas pela reticulação da proteína liofilizada de torta de mamona dos filmes produzidos, nem pela fibra de sisal nos espectros gerados. Em conclusão, o pH 12 de extração das proteínas da torta da mamona proporcionou melhores filmes produzidos com essas proteínas, e a adição de fibras de sisal não implicou em melhoras nas propriedades dos filmes, contrariamente ao glioxal. / Brazil is the world\'s third largest castor bean producer and the largest producer in South America. The castor bean oil has great potential in the biodiesel production chain, with interesting resource generation of its by-products such as the castor bean cake. Despite being rich in proteins, castor bean cake has limited application due to the presence of ricin, which presents high toxicity. Thus, hoping to enhance this byproduct with new technological applications, the aim of this thesis was the development of biodegradable film with the protein extracted from castor bean cake. Specifically, the effect of protein extraction pH (10, 11, 12) on some physical properties (thickness, mechanical properties, water solubility, permeability to water vapor and moisture) of the films was studied. From the evaluation of these results, it was then defined pH extraction of castor bean cake protein for the second study, which involved the production of films made of protein extracted from castor bean, reinforced with sisal fiber and/or glyoxal. Firstly, proteins were extracted in a reactor, by adding 20% of castor bean cake in a NaOH solution (pH = 10, 11 and 12), with 400 rpm stirring speed and 50°C. Separation of the protein extract from the insoluble residue was made by centrifugation (4,000 rpm). Extracts were freeze-dried and had their chemical composition and amino acids determined. Sorption isotherms of these proteins were determined at 25°C. The films were produced by casting, i.e., by dehydration of film-forming solutions prepared with constant protein concentration. In the first study, we used 7.5g protein/100g film-forming solution, crosslinking agent (0.8g glutaraldehyde/100g protein), and plasticizer (25g glycerol/100g protein). In the second study, it was used 6g protein/100g film-forming solution, crosslinking agent (0.5g glyoxal/100g protein), sisal fiber (20g fiber/100g protein) and plasticizer (25g glycerol/100g protein). The films were evaluated subjectively and objectively, by the assessment of the following determinations: thickness, gloss, color and opacity parameters, microstructure, mechanical properties for tensile and puncture force tests, moisture, film solubility in water, differential scanning calorimetry, sorption isotherms and Fourier transform spectroscopy. The freeze-dried proteins were rich in proteins (66-69%) for every studied pH, the mineral salts content was high (12-24%) as well, possibly due to the use of NaOH. No significant difference in the amino acid composition was observed for the tested extraction pH values. In the first study, the films presented brownish color and homogeneous visual appearance irrespective of the protein extraction pH. It was observed that the protein extraction pH influenced mechanical properties of the films. The increase in pH resulted in films more resistant to tensile and puncture, with tensile strength and puncture force values of 4.5MPa and 6.5N, respectively, to the films produced with proteins extracted in pH 12. However, regardless of the differences obtained, these films showed to be little extensible, with elongation at break and puncture deformation around 1.5% and 3.2%, respectively. The film solubility in water was also affected by the extraction pH of the castor bean cake proteins. While the film produced with proteins extracted at pH 10 was completely soluble in water, films made with proteins extracted at pH 12 showed solubility of 58.5%. The moisture of the films did not depend on pH and remained around 13%. In the second study, the addition of sisal fiber in the filmforming solution made the films rougher, without noticeable visual changes due to the presence of glyoxal. The addition of sisal fiber in the formulation increased film thickness from 0.11 to 0.16mm and reduced gloss measured at 60° angle, puncture force from 11.2 to 9.1N, the puncture deformation from 5.7 to 2.4%, the tensile strength from 10.3 to 5.1MPa, and the elongation at break from 78.5 to 24.2% without altering the elastic modulus of the films, which remained around 1.1-1.5MPa. The film solubility in water decreased from 42.8 to 36.8%, but the moisture of the films was not affected, which was remaining around 14%. The water vapor permeability increased about 50%, from 0.6 to 1.2 g.mm/h.m2.kPa. As for the color parameters, in general, the addition of the fibers caused an increase in lightness (L*) and opacity, and decreased the monochromatic a* and b*, and the total color difference (ΔE*). In the differential scanning calorimetry assay, the addition of fiber increased the glass transition temperature of the glycerol-rich fraction. Evaluating the sorption isotherms, it can be suggested that the fiber influenced the water absorption capacity of the films. It was not possible to detect changes in FTIR spectra produced by the crosslinking of castor bean cake freeze-dried protein of films, as well by the sisal fiber. In conclusion, the extraction at pH 12 of the castor bean cake proteins provided the best films produced, and the addition of sisal fibers did not result in improvements in film properties, contrary to glyoxal.

Orientadores: Mario Alexandre Coelho Sinhoreti, Simonides Consani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T00:21:44Z (GMT). No. of bitstreams: 1 Correr_AmericoBortolazzo_D.pdf: 1117938 bytes, checksum: 0ef6a45c368d8c4370d870253ec0d5ba (MD5) Previous issue date: 2009 / Resumo: O objetivo deste estudo foi verificar a influência do volume de compósito, técnica de fotoativação e sistema restaurador sobre a adaptação marginal, dureza Knoop e resistência de união de compósitos à dentina humana radicular. Este estudo foi dividido em 2 Capítulos. O Capítulo I verificou o efeito do volume de compósito (mantendo-se o mesmo fator C) e sistema restaurador sobre a adaptação marginal, dureza Knoop e resistência de união "push-out" a dentina radicular. Foram utilizados 90 pré-molares hígidos divididos em 9 grupos (n=10), de acordo com o volume de compósito (pequena, média e grande) e sistema restaurador (Filtek Z350, Filtek Z350 Flow e Filtek LS). Os compósitos foram fotoativados por LED Ultralume 5 (Ultradent) por 20 s para Filtek Z350, Filtek Z350 Flow e 40 s para Filtek LS. A adaptação marginal foi avaliada após 24h utilizando o método do corante superficial, medindo-se a porcentagem corada em relação ao perímetro da cavidade (Caries Detector). Após a análise da adaptação marginal, as amostras foram submetidas ao ensaio de resistência de união "push-out" e de dureza Knoop na superfície do compósito. Os dados foram submetidos à análise de variância dois fatores e teste de Tukey (p=0,05). O volume de compósito não influenciou a adaptação marginal dos compósitos. Filtek LS apresentou os melhores resultados de adaptação marginal e resistência de união. Os menores valores de resistência foram apresentados pelo Filtek Z350. O volume de compósito influenciou nos valores de resistência de união e de dureza Knoop, dependendo do compósito utilizado. Os maiores valores de dureza foram apresentados pelos volumes de compósito médios. A maior dureza foi do compósito Filtek Z350, seguido por Filtek LS e Filtek Z350 flow. No Capítulo II o objetivo foi verificar a influência da modulação da intensidade da luz durante a fotoativação e volume de compósito sobre a dureza Knoop e resistência de união do compósito Filtek Z350 à dentina radicular. Foram utilizados 90 pré-molares hígidos divididos em 9 grupos (n=10), segundo o volume de compósito (pequena, média e grande) e método de fototivação (luz contínua, "pulse delay" e "soft-start"). O compósito foi fotoativado por LED Ultralume 5 (Ultradent) pelos métodos citados anteriormente. Após 24h foi realizado o ensaio de resistência de união "push-out" e de dureza Knoop na superfície do compósito. Os dados foram submetidos à análise de variância dois fatores e teste de Tukey (p=0,05). Os resultados de resistência de união mostraram que os métodos de modulação da intensidade da luz foram superiores ao contínuo, sem diferença entre eles. Cavidade média foi significativamente superior que cavidade pequena e grande para o método contínuo. O ensaio de dureza Knoop mostrou que o melhor comportamento foi apresentado pelo método pulse delay e para cavidades médias. O volume de compósito influenciou os valores de resistência de união, dureza Knoop e adaptação marginal a dentina radicular. Os maiores valores de resistência de união e adaptação marginal foram apresentados pelo compósito Filtek LS e os maiores valores de dureza pelo compósito Filtek Z350. Os métodos de modulação da intensidade de luz mostraram os melhores resultados de resistência de união, sem detrimento dos valores de dureza Knoop. / Abstract: The polymerization shrinkage is one of the major drawbacks of the resin composites. The polymerization stress depends on the viscosity of the composite, rate of reaction, geometric configuration of the cavity and irradiance used during photoactivation. However, the volume of composite and low shrink monomers has been investigated. The aim of this study was to evaluate the influence of the cavity size, photoactivation technique and composite composition on marginal adaptation, Knoop hardness and push-out bond strength of composites to root dentin. This study was divided into 2 Chapters. In the Chapter 1 was to evaluate the effect of the cavity size (with similar C-factor) and restorative system on marginal adaptation, Knoop hardness and push-out bond strength to root dentin. Ninety premolars were divided into 9 groups, according to cavity size (small, middle and large) and resin composite (Filtek Z350, Filtek Z350 Flow e Filtek P90). The resin composites Filtek Z350, Filtek Z350 Flow were photoactivated with LED Ultralume 5 (Ultradent) for 20 s and Filtek P90 for 40 s. The marginal adaptation was analyzed after 24 h using Caries Detector. After that, the specimens were submitted to push-out Bond strength. The Knoop hardness examination was performed at the top surface. The data were submitted to ANOVA two-way and post hoc Tukey-s test at 95% significance level. The cavity size had no influence on marginal adaptation of the resin composites. Filtek P90 presented the best marginal adaptation, significantly better than other composites for large cavity. Filtek P90 showed the highest bond strength, significantly higher than other composites. Filtek Z350 showed the lowest bond strength results. Middle cavity presented Bond strength significantly higher than large cavity with the composite Filtek Z350. The highest Knoop hardness was showed by Filtek Z350, followed by Filtek P90 and Filtek Z350 flow. The aim of the Chapter 2 was to evaluate the influence of modulated photoacivation methods and cavity size on Knoop hardness and push-out bond strength of the composite Filtek Z350 to root dentin. Ninety premolars were divided into 9 groups, according to cavity size (small, middle and large) and photoactivation method (continuous light, pulse delay and soft-start). The composite was inserted and photoactivated with LED Ultralume 5 (Ultradent) by the methods aforementioned. The specimens were submitted to push-out Bond strength and Knoop hardness test. The data were submitted to ANOVA two-way and post hoc Tukey-s test at 95% significance level. Pulse delay showed the highest Bond strength results, significantly higher continuous light for small and large cavities. Middle cavity showed Bond strength significantly higher than small and large cavities for continuous light. Continuous light presented Knoop hardness significantly higher than soft-start for small cavity. For middle cavity, pulse delay showed Knoop hardness significantly higher than continuous light and soft-start. Pulse delay and soft-start showed Knoop hardness significantly higher than continuous light. The cavity size had influence on marginal adaptation, Knoop hardness and bond strength to root dentin. Filtek LS showed the highest bond strength and marginal adaptation results and Filtek Z350 presented the highest Knoop hardness results. The light intensity modulation methods showed the best bond strength results without decrease the Knoop hardness values. / Doutorado / Materiais Dentarios / Doutor em Materiais Dentários