The purpose of this research is to test the effects of methyltrimethoxysilane coupling agent on composite material containing calcium sulfite obtained from the Southern Illinois Power Co-operative. This scrubber material and the miscanthus plant are of interest due to their use in coal burning power plants to reduce toxic emission. When calcium sulfate is passed through coal fire gas emissions it absorbs mercury and sulfur. In these composites it is used as filler to reduce cost. Miscanthus is a source of both cellulose reinforcement and some natural resin. This plant has low care requirements, little mineral content, useful energy return, and positive environmental effects. Under investigation is whether a post-cure procedure or a silane coupling agent will positively impact the composite. Hot pressing alone may not be enough to fully cure the phenolic. It is hoped that the silane will increase the strength characteristics of the composite by enhancing adhesion between the calcium sulfite and phenolic resin. Possible effects on the miscanthus by the silane will also be tested. Phenolic is being utilized because of its recycling and biodegradable properties along with cost effectiveness in mass production. Composite mechanical performance was measured through 3-point bending to measure flexural strength and strain at breakage. A dynamic mechanical analyzer (DMA) was used to find thermomechanical properties. The post-cure was found to be effective, particularly on the final composite containing silane. When methyltrimethoxysilane was added to the miscanthus prior to fabrication, it was found to reduce flexural strength and density. However the addition of methyltrimethoxysilane to the calcium sulfite altered thermo-mechanical properties to a state more like pure phenolic, with added flexibility and thermal stability.

<p> UV radiation disinfection technology is an advantageous method of wastewater disinfection as it avoids the formation of chemical by-products typically found from chlorination. One challenge with this technology is avoiding fouling on the quartz sleeves in which the UV lamps are housed. In this study, using a model fouling system, the roles in fouling of light, and the constitution of the fouling media, are examined. The systematic determination of fouling by various mixtures of human serum albumin, humic acid, Ca^2+, and Fe^3+ was carried out on quartz slides in the presence and absence of UV (254nm) light. Fouling was assessed by the reduction in transmission of UV light through the quartz slides over time. It was determined that the most important factors were the concentration of..iron and protein, which apparently act synergistically to foul the surface. Other contributing factors to the magnitude of fouling include the flow rate and the age of the fouling solution. Most important was the presence of UV light. In all solutions examined, fouling was observed to a lower degree when the system was exposed to light. On the other hand, XPS analysis has demonstrated differences in the nature of the fouling layer on the surface exposed to UV light compared to that in the dark. </p> <p> It is generally accepted that low energy surfaces are less easily fouled than polar surfaces. Therefore, hydrophobic modification of the quartz by a series of different silane coupling agents was undertaken. Irrespective of the nature of the coating (alkylamine, alkyl, aryl, fluorocarbon, silicone), the rate and magnitude of fouling on the surface were comparable to the unmodified quartz. However, the more hydrophobic surfaces were easier to clean. </p> / Thesis / Master of Science (MSc)

The diploma thesis in the first part deals with a theoretical description of coating technologies, textile materials used in coatings, types of coated polymers and properties of coatings - especially adhesion. The experimental part of the work is devoted to the preparation of textile coatings from polyester fabric and coating based on addition silicone. Using the developed method of sample preparation for T-peel testing of the adhesive strength, the improvement of the adhesion of the coating by chemical adhesion with the support of adhesive agents was studied. The second method studied the change in compactness and adhesion of the coating to the fabric after shaking as a function of breathability. The influence of side reactions of reagents on silicone cohesion was studied by preparing dogbones for testing tensile-deformation properties. The research also included the characterization of silicone samples using ATR-FTIR, monitoring the weight gain and thickness of the fabric after coating, the feel and color stability of the applied fabric and observing the coating under an optical microscope.

La corrosion des canalisations métalliques pour le transport de gaz ou d’hydrocarbures est un problème critique qui peut avoir des répercussions financières et environnementales très importantes. Les revêtements polyoléfines tricouches sont largement utilisés pour préserver l’intégrité des structures. Ils sont constitués d’une sous couche mince époxy, d’une couche mince d’adhésif et d’une couche épaisse le plus souvent en polyéthylène. Ce système de revêtement bénéficie de très bonnes qualités d'adhérence. Néanmoins, des cas de décollements de ces revêtements à l’interface époxy/acier ont été constatés sur des pipelines en service depuis quelques années seulement, alors que la durée minimale de vie escomptée des tubes dans le sol est de quelques dizaines d’années. Ces décollements pourraient être dus à une dégradation progressive des liaisons interfaciales entre le primaire époxy et la surface métallique, associée à la présence de contraintes interfaciales importantes entre les différentes couches de l'assemblage. Cette étude vise alors d'une part à proposer des solutions permettant d’aboutir à la meilleure performance en vieillissement de la liaison adhésive, et d'autre part à quantifier les niveaux de contraintes au sein de la canalisation en acier revêtue depuis sa mise en œuvre, jusqu'à sa mise en service.Les liaisons interfaciales dépendant nécessairement de la préparation de surface de l’acier, des procédés de nettoyage ont été testés afin d’évaluer leur influence sur l’adhérence initiale et la durabilité des assemblages. Les préparations de surface permettent d'obtenir un degré de propreté et une rugosité. Ces deux éléments maximisent les forces de liaison et donc l'adhérence du revêtement. Le revêtement résiste alors mieux dans des environnements agressifs. Tous les procédés de nettoyage testés ont conduits à des niveaux de propreté équivalents du substrat en acier. Les essais effectués sur substrats polis miroir ont mis en évidence qu’une rugosité est nécessaire pour améliorer la durabilité des assemblages. La rugosité permet d'obtenir des adhérences supérieures à celles sur substrats polis miroir, de ralentir les effets du vieillissement humide et donc de prolonger la durée de vie du système. Il a été mis en évidence que les fortes rugosités étaient particulièrement bénéfiques pour les adhérences sèches. Par contre, au-delà d’une certaine rugosité, l’augmentation de la rugosité ne s’accompagne pas d’une amélioration significative de l’adhérence humide. Une étude sur l’apport des traitements de surface a aussi été menée. L’addition d’un traitement de surface a peu d’impact sur les adhérences initiales des assemblages, en comparaison avec une préparation de surface classique. Par contre les traitements de surfaces améliorent considérablement les adhérences humides, et donc la durabilité des assemblages. Notre travail prouve que le traitement aminosilane est un candidat potentiel en vue du remplacement du traitement toxique de chromatation, référence en matière de traitements de surface dans l'industrie des pipelines et dont l'utilisation sera interdite dans un futur proche compte tenu de l'évolution de la réglementation. Dans de bonnes conditions d'application et associé avec des primaires époxy appropriés, les adhérences sèches et humides obtenues avec les silanes sont comparables (voire supérieures) à celles de la chromatation.Par ailleurs, la modélisation par éléments finis du système tricouches a permis de préciser les niveaux de contraintes aux interfaces résultant de la mise en œuvre et de prévoir leur évolution au cours du temps et du vieillissement humide. / External Corrosion can weaken underground steel pipelines and render them unsafe for transporting oil or gas. Premature damage of this network could lead to dramatic financial and environmental consequences. Three layers polyolefin coatings composed by a fusion bonded epoxy, a modified polyolefin adhesive and a thick polyolefin topcoat, are the most widely systems used to preserve the structure integrity. This protective coating system presents excellent adhesion. Nevertheless, in some specific cases, loss of adhesion has been observed at steel/epoxy interface on operating pipelines on shorter period than their expected lifetime of about fifty years. This disbonding can be assigned to the progressive degradation of interfacial bonds between the epoxy primer and the metallic surface combined to substantial interfacial stresses between the different layers of the assembly. This study thus aims both to provide solutions to achieve the best ageing performance of the adhesive bond, and secondly to quantify the stress levels in a coated steel pipe since coating manufacturing to pipeline commissioning.Given that interfacial bonds depend necessarily on steel surface preparation, cleaning methods were compared to appraise their influence on assemblies dry and wet adhesion. Surface preparations allow to achieve a level of cleanness and to create a surface roughness. These two elements maximize binding forces and therefore the adhesion of the coating. The coating is thus more resistant to aggressive environments. All cleaning process have led to equivalent level of cleanness of steel substrate. Experiments carried out on mirror polished steel substrates highlighted that a surface roughness is necessary to improve joints durability. Roughness allows to obtain higher adhesion compared to mirror polished steel substrates, slows the effects of humid ageing and thus contributes to extend the durability of the system. It has been demonstrated that a high roughness is particularly beneficial for dry adhesion. By cons, beyond a certain roughness, increasing the surface roughness does not lead to significant improvement of wet adhesion. The benefits of surface treatments were also investigated. The addition of a surface treatment has little impact on dry adhesion in comparison with a conventional surface preparation. However, surface treatments substantially enhance the adhesion strength in wet stage, and therefore increase the durability of the assemblies. We also demonstrate that aminosilane surface treatments are competitive alternatives to traditional chromate conversion, which is the surface treatment of reference in pipeline industry, and whose use will be prohibited in a near future considering changes in legislation. Under good conditions of application and associated with appropriate fusion bonded epoxy, dry and wet adhesion obtained with silane surface treatments are comparable (or even higher ) than those obtained with chromate surface treatments.Furthermore, finite element modeling has allowed to specify interfacial stresses levels inside the assembly resulting from coating's manufacturing process and to predict their evolution over time and during wet ageing.

Micron size non-treated / silane coupling agent (SCA) treated serpentine filled acrylonitrile-butadiene-styrene (ABS) composite preparation and characterization of composites in terms of mechanical, thermal, flow properties and morphology were studied in this work. First step of the study was the size reduction of the as collected serpentine mineral. Secondly, three types of silane coupling agent treatments were applied to serpentine which were gamma-methacryloxypropyltrimethoxysilane (A-174), beta-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane (A-186) and gamma-mercapto-propyltrimethoxysilane (A-189). Non-treated and three different types of SCA treated serpentine minerals were melt mixed with ABS. Non-treated serpentine filled ABS composites had the serpentine weight fractions of 2%, 5%, 10% and 20%. On the other hand, SCA treated ones had serpentine weight fractions of 2%, 5% and 10%. Morphological analysis showed that SCA treatment was partly effective in interface interaction enhancement and A-186 gave the best results according to micrographs. There wasn&amp / #8217 / t any critical mechanical property loss up to 20% serpentine addition. Tensile tests revealed that SCA treatment increased the yield strength values of composites compared to non-treated serpentine filled composites. In accordance with morphological study, best result was obtained from 5% A-186 treated serpentine filled ABS as 12.9% improvement in yield strength value. Percent elongation at break values were increased with filler addition and greatest increase was observed in A-189 treated samples. Serpentine addition had no net effect on Young&amp / #8217 / s Modulus values. According to the impact testing results, A-189 treated samples had improved toughness compared to non-treated samples in accordance with elongation at break values. However increasing filler content resulted with decrease in impact strength values. DSC analysis showed that glass transion temperatures, especially for SCA treated samples, were decreased compared to neat ABS with filler addition. This result suggests that SCA may had the plasticizing effect on the composite. Flow properties of composites were not different from neat ABS up to 2% addition, when the filler concentration was further increased melt flow index values were dramatically decreased.

This study covers the recycling of waste poly(ethylene terephthalate) (PET) bottles through melt blending with low density polyethylene (LDPE) and polypropylene (PP). In general, polymer blends are known to be immiscible and incompatible with poor mechanical properties. This problem is due to the low intermolecular forces between the components of the immiscible blends. In order to enhance the interaction and compatibility between these matrices, some reactive or non-reactive copolymers were used. In this work / PET was treated with silane coupling agent (SCA) (low molecular weight reactive additive) for compatilization of LDPE-PP-PET blends. LDPE-PP-PET blends were prepared in different compositions (by weight) with and without silane coupling agent at high temperatures by a single screw extrusion and injection molding. Mechanical properties of treated and non-treated blends were studied in terms of tensile strength, strain at break and impact strength. Melt flow properties of blends were investigated by melt flow index. The impact fractured surfaces and thermal behaviour of the blends were examined with Scanning Electron Microscope (SEM) and Differential Scanning Calorimeter (DSC), respectively. Through out the studies, good adhesion between PET and LDPE-PP matrix was successfully achieved by the surface treatment of PET particles. The adhesion was also observed in SEM studies. Also the variation in mechanical properties was found to be highly dependent on the number of extrusion.

In this study, waterborne silicone-acrylic resin was produced by incorporating silane coupling agent onto the acrylic main chain by emulsion polymerization. After applying different emulsion polymerization processes, batch polymerization was selected to obtain the resultant resin. Thus finding the optimum conditions by investigating the parameters of monomer ratios, initiators, concentrations of initiators, temperature and time, the novel resin was synthesized. Water-dispersed silicone-acrylic resin was produced using butyl acrylate, butyl methacrylate, methyl methacrylate, 3-methacryloxypropyltrimethoxysilane and acrylic acid as a hydrophilic monomer. 2,2&#039 / -azobis[2-(2-imidazolin-2yl)propane]dihydrogen chloride as thermal initiator and t-butyl hydroperoxide / sodiummetabisulfite as redox couple initiator were selected as the best effective initiators for the production of silicone-acrylic resin. The reaction temperature of the preparation of silicone-acrylic resin was taken as 50&amp / #61616 / C maximum to prevent gelation and agglomeration. To understand the effect of silane coupling agent on the properties of the resin, a new resin was synthesized which did not contain any silane coupling agent and the properties of both resins were determined by FTIR spectroscopy, thermal analysis and mechanical tests. Their physical properties were also determined. The addition of 3-methacryloxypropyltrimethoxysilane to the main chain increased the hardness and the gloss values but slightly decreased the abrasion resistance value of the silicone-acrylic resin. All the samples showed superior flexibility. The produced polymer which contains silane coupling agent showed excellent adhesion properties on glass and metal plates.

Theoretical part of master's thesis is focused on chemical treatments of natural fibers and their use as reinforcement material in polymer composites. Flax fibers were treated with two different silane coupling agents to improve their adhesion with polymer matrix. Nature of treatment was studied by using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Composites based on both treated and untreated flax fibers were prepared by pultrusion.technique. Mechanical properties and water absorption of prepared composites were evaluated.

Hybrid carbon fiber reinforced composites are a new breed of materials that are currently being explored and characterized for next generation aerospace applications. Through the introduction of secondary reinforcements, such as alumina nanoparticles, hybrid properties including improved mechanical properties and stress sensing capabilities can be achieved. In order to maximize these properties, it is necessary to achieve a homogeneous dispersion of particulate filler. Utilizing the photoluminescent properties of alumina, it is possible to compare local levels of particle concentration through emission intensities as a way to determine the effectiveness of the tested manufacturing parameters in increasing material homogeneity. Parameters of these photoluminescence emissions have been established to be stress dependent, which allows for in situ residual stress measurements. It is shown here that the application of silane coupling agents as particle surface treatments improves particle dispersion when compared to untreated samples. Reactive silane coupling agent (RSCA) treatments were found to provide for greater dispersion improvements when compared to non-reactive silane coupling agents (NRSCA). Higher resolution investigations into these samples found that treatment with a reactive coupling agent altered the stress state of particles concentrated around the fiber from a tensile stress state to a compressive stress state. This is proposed to result from bonding of the reactive groups on the coupling agent to the organic groups on the carbon fibers which adjusts the stress state of the particle. Future mechanical tests will verify the effects of the particle surface functionalization treatments on mechanical properties of the composites.

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