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.

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.

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.

Glass fiber reinforced poly(ethylene terephthalate), GF/PET has excellent potential for future structural applications of composite materials. PET as a semi-crystalline thermoplastic polyester has high wear resistance, low coefficient of friction, high flexural modulus and superior dimensional stability make it a versatile material for designing mechanical and electromechanical parts. Glass fibers are currently used as strength giving material in structural composites because of their high strength and high performance capabilities. In order to obtain high interfacial adhesion between glass fiber and polymer, glass fibers are treated with silane coupling agents. The objective of this study is to produce GF/PET composites with varying glass fiber concentration at constant process parameters in a twin screw extruder. Also, by keeping GF content constant, it is aimed to observe the effects of process parameters such as screw speed and feed rate on structural properties of the composites. Another objective of the study is to investigate the influence of different coupling agents on the morphological, thermal and mechanical properties and on fiber length distributions of the composites. Tensile strength and tensile moduli of the GF/PET composites increased with increasing GF loading. There was not a direct relation between strain at break values and GF content. The interfacial adhesion between glass fiber received from the manufacturer and PET was good as observed in the SEM photograps. Degree of crystallinity values increased with the addition of GF. Increasing the screw speed did not affect the tensile strength of the material significantly. While increasing the feed rate the tensile strength decreased. The coupling agent, 3-APME which has less effective functional groups than the others showed poor adhesion between glass fiber and PET. Therefore, lower tensile properties were obtained for the composite with 3-APME than those of other silane coupling agents treated composites. Number average fiber length values were reduced to approximately 300&amp / #61549 / m for almost all composites prepared in this study.

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