Composites, though used in a variety of applications from chairs and office supplies to structures of U.S. Navy ships and aircrafts, are not all designed to hold up to extreme heat flux and high temperature. Fiber-reinforced polymeric composites (FRPC) have been proven to provide the much needed physical and mechanical properties under fire exposure. FRPC notable features are its combination of high specific tensile strength, low weight, along with good corrosion and fatigue resistance. However FRPC are susceptible to thermal degradation and decomposition, which yields flammable gas, and are thus highly combustible. This property restricts polymeric material usage. This study developed a numerical model that simulated the degradation rate and temperature profiles of a fiber-reinforced polyester resin composite exposed to a constant heat flux and hydrocarbon fire in a cone calorimeter. A numerical model is an essential tool because it gives the composite designer the ability to predict results in a time and cost efficient manner. The goal of this thesis is to develop a numerical model to simulate a zonal-layer polyester resin and fiberglass mat composite and then validate the model with experimental results from a cone calorimeter. By inputting the thermal properties of the layered composite of alternating polymer and polymer-infused glass fiber mat layers, the numerical model is one step closer to representing the experimental data from the cone calorimeter test. The final results are achieved through adding a simulated heat flux from the pilot ignition of the degraded gas of the polyester resin. The results can be coupled into a mechanical model, which may be separately constructed for future study on the mechanical strength of composites under fire conditions.

This thesis presents the characterization of the optical and mechanical properties of silica nanoparticle films fabricated by ionic self-assembly, also known as layer-by-layer (LbL) deposition. Utilizing electrostatic attraction of oppositely-charged materials permits uniform and rapid growth of the constituents onto planar and curved surfaces. In this work, silica nanoparticles are adsorbed onto glass and polycarbonate substrates, as well as micron-scale glass fibers, with the purpose of improving the optical quality of the respective media. Several methods are presented to improve the adhesion and cohesion of silica nanoparticle films on glass substrates. In the first method, the substrate and nanoparticle surfaces are coated with materials containing sulfonate end groups. Next, a photo-reactive polycation known as diazo-resin (DAR) is used in ISAM deposition with the modified silica nanoparticles. Subsequent exposure to UV converts the ionic bonds between the DAR and sulfonate groups into covalent ones. The second method to improve the mechanical strength is to heat the ISAM silica nanoparticle film at a high enough temperature (500 °C) to remove the polymer and partially fuse the nanoparticles. This technique is known as calcination and is shown to significantly improve the mechanical robustness of the film without compromising the optical properties. The final method involves the deposition of precursor and capping polymer layers around bulk silica nanoparticle films with both bilayer and quadlayer designs. The addition of these polymer layers improves the surface contact between adjacent nanoparticles but reduces the film porosity and consequently the optical transparency. Currently the calcination technique is the only one that significantly improves the film adhesion and cohesion, but suggestions are offered to potentially improve the performance of films made by the other two methods. An alternative way to functionalize polycarbonate substrates for silica nanoparticle ISAM deposition is also presented. The molecular structure of polycarbonate at the surface can be modified by exposing it to deep UV (λ = 185, 254 nm). By doing so, the surface becomes populated with carboxylate species, and thus permits ISAM deposition of poly(allylamine hydrochloride) (PAH) and silica nanoparticles. A variety of spectroscopic methods show that the molecular structure is changed by this procedure, and SEM shows that UV treatment improves the uniformity of ISAM films on polycarbonate. Finally, PAH/silica nanoparticle ISAM films are deposited onto glass fibers. The fibers are used for mechanical reinforcement of polymer composite optical media. The role of the nanoparticle film on the fibers is to reduce light scattering at the interfaces of materials with different thermo-optic coefficients, in other words, transmittance losses associated with changes in temperature. Fiber bundles coated with silica nanoparticles suffer from unacceptable levels of aggregation, and hence do not currently improve the transmittance over the temperature spectrum. Some evidence is presented, however, to suggest that the transparency can be improved if fiber aggregation during ISAM deposition can be avoided. / Ph. D.

This dissertation presents the first reported identification and analyses of the phase relations in the YBa2Cu3O7-x (YBCO)-SiO2 system at elevated temperatures. In this regard, a rigorous characterization study of the reaction phases within YBCO glass fibers, heat-treated YBCO+SiO2 pellets, rapid thermally annealed YBCO+SiO2 rods and rapid thermally annealed YBCO powder inside a fused silica tube is provided. These analyses are based on a vast set of generated novel results obtained using energy dispersive spectroscopy analyses on an environmental scanning electron microscope, X-Ray diffraction analyses, Raman spectroscopy, X-ray photoelectron spectroscopy analyses and a cross-polarized light study. First, original drawings of YBCO into glass fibers using the molten-core approach on a fiber draw tower in air and oxygen atmospheres are presented and analyzed. The performed analyses reveal the occurrence of reactions between the YBCO core and the silica cladding in as-drawn fibers as well as after additional heat-treatments. A detailed analysis and characterization of the occurring dissolution and diffusion based reaction processes is, then, provided along with the identification of the arising phase separation. Moreover, in order to analyze drawing YBCO glass fibers at lower temperatures, the use of borosilicate as the preform material is also investigated. This varied set of experiments and associated analyses reveal that the as-drawn YBCO fibers contain an amorphous core and that cuprite (Cu2O) is the first phase to crystallize out of the amorphous silicate matrix upon heat-treatment. Furthermore, the obtained results demonstrate the dissolution of the fused silica cladding into Si4+ and O2- ions and their subsequent diffusion into the molten YBCO core, leading to phase separation due to an occurring miscibility gap in the YBCO-SiO2 system as well as to silicate formation and amorphization of the YBCO core. This, as a result, prohibits the formation of the superconductive YBCO (Y-123) phase upon annealing. In addition, heat-treatment analyses show that higher temperatures or prolonged dwelling times at lower temperatures lead to the formation of barium copper and yttrium barium silicates. The analysis focusing on the use of borosilicate as the preform material reveals that drawing at lower temperatures reduces the dissolution and diffusion based reactions, but does not prevent them. Furthermore, the analysis on YBCO glass fibers with a fused silica cladding drawn in oxygen atmosphere shows that a higher oxygen content increases the dissolution of the fused silica cladding into its ions and their subsequent diffusion into the molten YBCO core. In addition, the performed heat-treatments on YBCO+SiO2 pellets in air and oxygen atmospheres demonstrate the gradual decomposition of the Y-123 phase with an increase in SiO2 content. Moreover, the rapid thermal annealing experiments with a subsequent quenching step on YBCO+SiO2 rods and on YBCO powder inserted inside a fused silica tube show the decomposition of the Y-123 phase and the formation of phases similar to the phases obtained in the YBCO glass fiber study, thus corroborating the results thereof. In summary, this dissertation enables the determination of the phase relations and reaction processes within the YBCO-SiO2 system, the identification of the direct effects of the silicon content on the Y-123 phase decomposition, as well as a rigorous characterization of the dissolution and diffusion based reactions within the YBCO-SiO2 glass-clad fiber system. The generated results and drawn conclusions build a fundamental understanding of phase relations in the YBCO-SiO2 system, which enables a definite assessment of the feasibility of manufacturing long-scale purely superconductive YBCO glass fibers using the molten-core approach and introduces advanced contributions to general glass-clad fiber systems manufactured using this method. / Doctor of Philosophy / This dissertation provides the first reported identification and analysis of the phase relations in the YBa2Cu3O7-x (YBCO)-SiO2 system at high temperatures. In this regard, a thorough characterization study of the reaction phases within YBCO glass fibers drawn using the molten-core approach on a fiber draw tower is provided. In addition, heat-treatment analyses considering YBCO+SiO2 pellets, rapid thermally annealed YBCO+SiO2 rods and rapid thermally annealed YBCO powder inside a fused silica tube are performed to gain further fundamental insights. The performed analyses are based on a wide set of characterization methods including energy dispersive spectroscopy on an environmental scanning electron microscope, X-Ray diffraction analyses, Raman spectroscopy, X-ray photoelectron spectroscopy and a cross-polarized light study. Our experimental results and performed analyses identify the phase relations and reaction processes within the YBCO-SiO2 system at elevated temperatures, demonstrate the direct effects of the silicon content on the superconductive YBCO phase decomposition, enable drawing definite conclusions regarding the feasibility of manufacturing long-scale purely superconductive YBCO glass fibers using the molten-core approach, and, characterize the dissolution and diffusion based reactions occurring within the YBCO-SiO2 glass-clad fiber system. In a nutshell, this dissertation provides a fundamental understanding of phase relations in the YBCO-SiO2 glass-clad system as well as key insights covering general glass-clad fibers drawn using the molten-core approach, paving the way for improved glass-clad fiber manufacturing using this method.

The application of glass fiber reinforced composites has grown rapidly due to their high strength-to-weight ratio, low cost, and chemical resistance. However, the increasing demand for fiber reinforced composites results in the generation of more composite wastes. Mechanical recycling is a cost-effective and environmentally-friendly recycling method, but the loss in the quality of recycled glass or carbon fiber composite hinders the wide-spread use of this recycling method. It is important to develop novel composite materials with higher recyclability. Thermotropic liquid crystalline polymers (TLCPs) are high-performance engineering thermoplastics, which have comparable mechanical performance to that of glass fiber. The TLCP reinforced composites, called in situ composites, can form the reinforcing TLCP fibrils during processing avoiding the fiber breakage problem. The first part of this dissertation is to study the influence of mechanical recycling on the properties of injection molded TLCP and glass fiber (GF) reinforced polypropylene (PP). The processing temperature of the injection molding process was optimized using a differential scanning calorimeter (DSC) and a rheometer to minimize the thermal degradation of PP. The TLCP and GF reinforced PP materials were mechanically recycled up to three times by repeated injection molding and grinding. The mechanical recycling had almost no influence on the mechanical, thermal, and thermo-mechanical properties of TLCP/PP because of the regeneration of TLCP fibrils during the mold filling process. On the other hand, glass fiber/PP composites decreased 30% in tensile strength and 5% in tensile modulus after three reprocessing cycles. The micro-mechanical modeling demonstrated the deterioration in mechanical properties of GF/PP was mainly attributed to the fiber breakage that occurred during compounding and grinding. The second part of this dissertation is concerned with the development of recyclable and light weight hybrid composites through the use of TLCP and glass fiber. Rheological tests were used to determine the optimal processing temperature of the injection molding process. At this processing temperature, the thermal degradation of matrix material was mitigated and the processability of the hybrid composite was improved. The best formulation of TLCP and glass fiber in the composite was determined giving rise to the generation of a recyclable hybrid composite with low melt viscosity, low mechanical anisotropy, and improved mechanical properties. Finally, TLCP reinforced polyamide composites were utilized in an additive manufacturing application. The method of selecting the processing temperature to blend TLCP and polyamide in the dual extrusion process was devised using rheological analyses to take advantage of the supercooling behavior of TLCP and minimize the thermal degradation of the matrix polymer. The composite filament prepared by dual extrusion was printed and the printing temperature of the composite filament that led to the highest mechanical properties was determined. Although the tensile strength of the TLCP composite was lower than the glass fiber or carbon fiber composites, the tensile modulus of 3D printed 60 wt% TLCP reinforced polyamide was comparable to traditional glass or carbon fiber reinforced composites in 3D printing. / Doctor of Philosophy / The large demand for high performance and light weight composite materials in various industries (e.g., automotive, aerospace, and construction) has resulted in accumulation of composite wastes in the environment. Reuse and recycling of fiber reinforced composites are beneficial from the environmental and economical point of view. However, mechanical recycling deteriorates the quality of traditional fiber reinforced composite (e.g., glass fiber and carbon fiber). There is a need to develop novel composites with greater recyclability and high-performance. Thermotropic liquid crystalline polymers (TLCP) are attractive high performance materials because of their excellent mechanical properties and light weight. The goal of this work is to generate recyclable thermotropic liquid crystalline polymer (TLCP) reinforced composites for use in injection molding and 3D printing. In the first part of this work, a novel recyclable TLCP reinforced composite was generated using the grinding and injection molding. Recycled TLCP composites were as strong as the virgin TLCP composites, and the mechanical properties of TLCP composites were found to be competitive with the glass fiber reinforced counterparts. In the second part, a hybrid TLCP and glass fiber reinforced composite with great recyclability and excellent processability was developed. The processing conditions of injection molding were optimized by rheological tests to mitigate fiber breakage and improve the processability. Finally, a high performance and light weight TLCP reinforced composite filament was generated using the dual extrusion process which allowed the processing of two polymers with different processing temperatures. This composite filament could be directly 3D printed using a benchtop 3D printer. The mechanical properties of 3D printed TLCP composites could rival 3D printed traditional fiber composites but with the potential to have a wider range of processing shapes.

The static and dynamic flexural properties of a wood fiber matrix internally reinforced with continuous glass fibers were investigated. When modelled as a sandwich composite, the static flexural modulus of elasticity (MOE) of glass fiber reinforced hardboard could be successfully predicted from the static flexural MOE of the wood fiber matrix, and the tensile MOE and effective volume fraction of the glass fiber reinforcement. Under the same assumption, the composite modulus of rupture (MOR) is a function of the reinforcement tensile MOE and effective volume fraction, and the matrix stress at failure. The composite MOR was predicted on this basis with limited success. The static flexural modulus of elasticity, dynamic modulus of elasticity, and modulus of rupture of glass fiber reinforced hardboard increased with increasing effective reinforcement volume fraction. The logarithmic decrement of the composite decreased with increasing effective reinforcement volume fraction. Excellent linear correlation found among flexural properties determined in destructive static tests and nondestructive dynamic tests demonstrated the usefulness of dynamic test methods for flexural property evaluation. The short-term flexural creep behavior of glass fiber reinforced hardboard was accurately described by a 4-element linear viscoelastic model. Excellent agreement existed between predicted and observed creep deflections based on nonlinear regression estimates of model parameters. / Ph. D.

Resíduos da área de engenharia civil decorrentes da recuperação de estruturas danificadas por agentes agressivos contribuem continuadamente para impactar o meio ambiente de maneira cada vez mais preocupante. O desenvolvimento de novas tecnologias que sejam aceitáveis do ponto de vista ambiental e financeiro provou ser um grande desafio na solução desse problema quando se compara o custo original e eficaz em médio e longo prazo ao custo da demolição, destinação desse material e reconstrução da obra. Para viabilizar a utilização de compósitos de fibras sintéticas como reforço resistente a ambientes agressivos em elementos de concreto, os aparatos de ensaio e os corpos de prova foram modificados e adaptados aos sistemas operacionais descritos pelas normas técnicas vigentes, a partir da concepção do uso de filamentos de fibra contínua. Dado o caráter inovador do trabalho, não se identificou uma norma que tratasse especificamente dos ensaios de flexão nem pullout com fibras contínuas em blocos de concreto. Portanto, para se conseguir um aproveitamento desse tipo de reforço que respondesse satisfatoriamente quando comparado às armaduras metálicas, foi aplicada uma rugosidade à superfície da haste para garantir sua aderência ao bloco de concreto. Pelo método de preparo de compósitos de matriz cimentícia proposto no presente estudo, foram determinados os valores da força de arrancamento dos reforços com fibras de carbono e vidro-AR, os quais, no caso das fibras de carbono, apresentaram aumentos significativos entre 76% e 158% e 47% e 120% respectivamente para concretos de resistência à compressão de 30 MPa (fcm 30) e 40 MPa (fcm 40) comparados com valores obtidos para barras de aço. / In Civil Engineering, the waste from the recovery of structures that were damaged by aggressive agents continuously contribute to impact the environment in an increasingly concerning way. The development of new technologies that would be environmentally and financially acceptable has become a major challenge to solve that problem when one compares the medium and long term original and effective cost to the cost of demolition, destination of that material and rebuilding. To enable the use of synthetic fiber composites as a resistant reinforcement to aggressive environments in concrete elements, the test apparatus and the specimens were changed and suited to the operational systems described by current technical standards from the conception of the use of continuous fiber filaments. Given the innovative character of the present work, no standard specifically related to bending and pullout tests with continuous fibers in concrete blocks has been identified. Therefore, in order to obtain good use of that kind of reinforcement that would respond satisfactorily when compared to metallic bars, some rugosity was applied to the rod surface in order to ensure its adherence to the concrete block. The preparation method of cement matrix composites proposed in the present work has determined pullout strength values and reinforcement with carbon and AR glass fiber values, which, regarding carbon fibers, showed significant increase between 76% and 158% and 47% and 120% respectively for compression resistant concrete of 30 MPa (fcm 30) and 40 MPa (fcm 40) compared to the obtained values for steel bars.

Resíduos da área de engenharia civil decorrentes da recuperação de estruturas danificadas por agentes agressivos contribuem continuadamente para impactar o meio ambiente de maneira cada vez mais preocupante. O desenvolvimento de novas tecnologias que sejam aceitáveis do ponto de vista ambiental e financeiro provou ser um grande desafio na solução desse problema quando se compara o custo original e eficaz em médio e longo prazo ao custo da demolição, destinação desse material e reconstrução da obra. Para viabilizar a utilização de compósitos de fibras sintéticas como reforço resistente a ambientes agressivos em elementos de concreto, os aparatos de ensaio e os corpos de prova foram modificados e adaptados aos sistemas operacionais descritos pelas normas técnicas vigentes, a partir da concepção do uso de filamentos de fibra contínua. Dado o caráter inovador do trabalho, não se identificou uma norma que tratasse especificamente dos ensaios de flexão nem pullout com fibras contínuas em blocos de concreto. Portanto, para se conseguir um aproveitamento desse tipo de reforço que respondesse satisfatoriamente quando comparado às armaduras metálicas, foi aplicada uma rugosidade à superfície da haste para garantir sua aderência ao bloco de concreto. Pelo método de preparo de compósitos de matriz cimentícia proposto no presente estudo, foram determinados os valores da força de arrancamento dos reforços com fibras de carbono e vidro-AR, os quais, no caso das fibras de carbono, apresentaram aumentos significativos entre 76% e 158% e 47% e 120% respectivamente para concretos de resistência à compressão de 30 MPa (fcm 30) e 40 MPa (fcm 40) comparados com valores obtidos para barras de aço. / In Civil Engineering, the waste from the recovery of structures that were damaged by aggressive agents continuously contribute to impact the environment in an increasingly concerning way. The development of new technologies that would be environmentally and financially acceptable has become a major challenge to solve that problem when one compares the medium and long term original and effective cost to the cost of demolition, destination of that material and rebuilding. To enable the use of synthetic fiber composites as a resistant reinforcement to aggressive environments in concrete elements, the test apparatus and the specimens were changed and suited to the operational systems described by current technical standards from the conception of the use of continuous fiber filaments. Given the innovative character of the present work, no standard specifically related to bending and pullout tests with continuous fibers in concrete blocks has been identified. Therefore, in order to obtain good use of that kind of reinforcement that would respond satisfactorily when compared to metallic bars, some rugosity was applied to the rod surface in order to ensure its adherence to the concrete block. The preparation method of cement matrix composites proposed in the present work has determined pullout strength values and reinforcement with carbon and AR glass fiber values, which, regarding carbon fibers, showed significant increase between 76% and 158% and 47% and 120% respectively for compression resistant concrete of 30 MPa (fcm 30) and 40 MPa (fcm 40) compared to the obtained values for steel bars.

Orientadores: Lucia Helena Innocentini Mei, Jose Alexandrino de Sousa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-12T07:01:46Z (GMT). No. of bitstreams: 1 Giraldi_AndreLuisFerrarideMoura_D.pdf: 6788806 bytes, checksum: f1a0282da8520c3138e10549183d79b6 (MD5) Previous issue date: 2008 / Resumo: Uma aplicação importante do poli (tereftalato de etileno) - PET - pós-consumo a ser considerada, e ainda pouco explorada, diz respeito ao seu reaproveitamento em outros setores diferentes, tais como o de compósitos híbridos de fibra de vidro (FV) com matriz polimérica e modificador de impacto, para aplicações diversas na área de engenharia. Deste modo, se fez necessário um estudo sistemático de compósitos de PET, reforçado com fibra de vidro e modificador de impacto para sua utilização numa aplicação de engenharia. E necessário que este apresente uma boa relação entre propriedades de rigidez e resistência ao impacto, e para isto dois sistemas de reforço foram propostos com dois tipos de fibra de vidro com diferentes tratamentos superficiais (FV 952 e 983). Ensaios de reometria de torque indicaram a reatividade entre os componentes PET e modificador de impacto. Os ensaios mecânicos demonstraram que o modulo elástico e a resistência a tração dos compósitos diminuem conforme se aumenta a concentração de E-MA-GMA em substituição ao PET na matriz. Entretanto, o modulo e a resistência ao impacto aumentaram da ordem de 300 % e 900% respectivamente para as concentrações de 30% de fibra de vidro (FV 952) e 20% de E-MA-GMA. O modulo de elasticidade e independente do tipo de tratamento superficial da fibra de vidro. A resistência a tração e a resistência ao impacto Izod dependem da natureza do tratamento de silano usado. / Abstract: An important application of poly(ethylene terephtalate) - PET - to be considered, and still not well explored, is its re-use in other different sectors, such as the obtaintion of PET composites reinforced with fibre glass (FG) and elastomer, for several applications in the engineering area. In this way, it is necessary a systematic study of several PET composites hybrids reinforced with fibre glass and impact elastomer to obtain a good balance between engineering properties such strength, rigidity ans impact resistance, two systems of reinforced were investigated using two types treatment of surface different (FG 952 and 983). Torque rheometry investigations during composite mixing indicated the reactivity between PET and elastomer. Mechanical tensile test on PET / fibre glass / elastomer composites hybrids indicated that the elastic modulus and tensile strength reduce monotonically as higher volume fractions of E-MA-GMA substitute PET in the composite matrix. Composites hybrids with 30 wt% of fibre glass (FG 952) and 20 wt% of elastomer indicates mechanical gains of the order of 300% in modulus e 900 % Izod impact. Tensile modulus is relatively independent of type of silane treatment applied to the glass fibers. Yield strength and Izod impact strength depend on the nature of silane treatment used. / Doutorado / Ciencia e Tecnologia de Materiais / Doutor em Engenharia Química

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-09-15T19:46:11Z No. of bitstreams: 1 fabricioreskallaamaral.pdf: 2335161 bytes, checksum: 6c05fb00dba6c1d1e2679f0a3289f9ca (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-09-26T20:21:13Z (GMT) No. of bitstreams: 1 fabricioreskallaamaral.pdf: 2335161 bytes, checksum: 6c05fb00dba6c1d1e2679f0a3289f9ca (MD5) / Made available in DSpace on 2016-09-26T20:21:13Z (GMT). No. of bitstreams: 1 fabricioreskallaamaral.pdf: 2335161 bytes, checksum: 6c05fb00dba6c1d1e2679f0a3289f9ca (MD5) Previous issue date: 2010-07-26 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / OBJETIVO: Avaliar, por meio do ensaio de microtração, diferentes protocolos utilizados na esplintagem dentária, com fibra de vidro (FV), adesivo (Ad), resina flow (RF) e resina composta nanoparticulada (RCN). MATERIAIS E MÉTODOS: Foram confeccionados 84 blocos de resina nanoparticulada , com dimensões de 4,5 x 8 x 7mm e divididos em 7 grupos. Os blocos foram pareados (n=6) conforme o fator “protocolo de esplintagem”: Gr1- Ad ; Gr2- FV ; Gr3- FV + Ad; Gr4- RF+ FV + Ad; Gr5- FV + Ad + RF; Gr6- FV + RF + Ad; Gr7- RF + FV. Após, os conjuntos foram seccionados com um disco de diamante dupla face em um torno específico para corte dos corpos-de-prova em forma de palito (CP) com interface adesiva de 1mm2 sendo, posteriormente, submetidos ao teste de microtração (µTBS) em máquina de ensaio universal EMIC à velocidade de 1mm/s com célula de carga de 50KGF. Para determinar a fratura, as interfaces adesivas foram analisadas em microscópio eletrônico de varredura e os resultados submetidos à análise de variância ANOVA 1fator e teste Tukey para comparação das médias (α=5%). RESULTADOS: As médias (MPa) e desvio padrão (MPa) para µTBS foram: Gr1- 22,4 (13,4); Gr2- 3,9 (4,2);Gr3- 17,2 (7,7);Gr4- 12,6 (6,9);Gr5- 6,4 (5,5);Gr6- 7,8 (9,7);Gr7-12,1 (10,9). A análise estatística verificou diferença significante entre os grupos. CONCLUSÃO: Houve diferença estatisticamente significante (p< 0.05) na resistência de união entre os protocolos de esplintagem avaliados; o maior valor médio de resistência de união foi obtido pelo protocolo do grupo controle 1 (resina composta + adesivo); entre os grupos testes, o maior valor médio de resistência de união foi obtido pelo protocolo do grupo 3 (resina composta + fibra de vidro + adesivo). / OBJECTIVE: This study evaluated in vitro "different protocols used in the dental splinting with fiber glass (FG), adhesive (Ad), resin flow (RF) and nanoparticle composite (RCN). MATERIALS AND METHODS: We made 84 resin blocks nanoparticule with dimensions 4.5 x 8 x 7 mm and divided into seven groups. The blocks were paired (n = 6) as the factor "protocol splinting": Gr1-Ad; Gr2- FV; Gr3- FV + Ad; GR4- RF + FV + Ad; GR5- FV + Ad + PR; GR6- FV+ Ad + PR +; GR7- RF + FV. After the sets were cut with a diamond disc double-sided on a lathe for cutting specific bodies-of - proof-shaped stick (CP) at the bonding interface of 1mm2 was later submitted to microtensile test (μTBS) in EMIC universal test machine at a speed of 1mm / s with load cell 50kgf. To determine the fracture, the adhesive interfaces were examined in a scanning electron microscope and the results submitted to analysis of variance one-factor ANOVA and Tukey test for comparison of means (α = 5%). RESULTS: Mean (MPa) and standard deviation for μTBS were Gr1-22.4 (13.4); Gr2-3.9 (4.2); Gr3-17.2 (7.7); GR4-12, 6 (6.9); GR5-6.4 (5.5); GR6-7.8 (9.7); GR7-12, 1 (10.9). Statistical analysis found significant differences between groups. CONCLUSION: CONCLUSION: There was a statistically significant difference (p <0.05) in bond strength between splinting protocols evaluated, the larger value of bond strength was obtained by the filing of a control group (resin + adhesive) between the test groups, the highest average value of bond strength was obtained by the protocol of group 3 (composite resin + glass fiber + adhesive).

Diploma's thesis describes resolution of cause technological problems in mineral wool manufacturig in company Saint-Gobain Orsil. Main attention is paid to thermal and volatile process in mineral wool from filtration chamber and common commercial sales. Samples of mineral wool were characterizated by thermal analysis (simultaneous TG-DTA), effluent gas analysis (EGA), infrared spectroscopy (FT-IR), electron microscopy (SEM) and X-ray diffraction (XRD). Thermal analysis experiments was used to check thermal volatile processes. Technological problem of burning is linked with rise of isocyanic acid.