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Hybrid dental composites combining short fibers and particulate fillers
Klieštiková, Nikola ; Přikryl, Radek (referee) ; Bystřický, Zdeněk (advisor)
This work deals with the hybrid composite material combining particulate filler with short fibers for dental applications. The barium micro-filler and the short glass fibers were treated with -methacryloxypropyltrimethoxysilane in cyclohexane using n-propylamine. The barium micro-filler and the short glass fibers were mixed with the matrix based on a dimethacrylate resin. The effects of the addition of short glass fibers on mechanical properties were studied. Surface treatment of the filler was characterized by thermogravimetric analysis (TGA) and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). Fracture surfaces and the adhesion to the matrix was observed by scanning electron microscope (SEM). The modulus of elasticity and strenght was determined by three point bending flexural test. Critical values of the stress intensity factor annd energy release rate were determined using the three point bending flexural test of notched specimens. The particulate filler increased the flexural modulus of elasticity and fragility. The addition of short fibers had little effect on flexural modulus of elasticity, but increased the flexural strength and fracture toughness of the specimen.
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Využitelnost recyklátu dřevovláknitých desek ve výrobě kompozitních materiálů
Valko, Filip
The research dealt with the issue of the usability of fiberboard recyclate in the production of composite materials based on particleboard and wood fiber. The investigated properties were moisture content, density, density profile, thickness swelling, flexural strength, modulus of elasticity and tensile strength perpendicular to the fibers. The results were evaluated in Excel after the tests. A comparison of the results between the different boards was then carried out. The use of recycled wood fiber in composite materials has a positive effect on the physical properties, modulus of rupture and tensile strength perpendicular to the plane of the board.
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Posouzení využitelnosti vybraných listnatých dřev pro výrobu kompozitu na bázi dřeva
Kašpařík, Matěj
The bachelor thesis deals with the issue of the possibility of replacing spruce wood in the production of OSB with hornbeam and birch wood. The purpose of the thesis is to compare selected physical and mechanical properties of OSB made of these woods with standardized properties of OSB. In the first part, the origin, characteristics and current use of OSB are presented. The second part deals with the material and methodology of all the tests performed. The following properties of the boards were investigated: moisture content, flexural strength and elastic limit, density profile, swelling, delamination and shear strength of the glued joint. In the third part of the paper, the results of the tests and their comparison with the standard requirements for OSB are presented, followed by a summary and discussion.
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Posouzení využitelnosti vybraných listnatých dřev pro výrobu kompozitu na bázi dřeva
Mišičák, Patrik
The bachelor thesis deals with the assessment of the usability of alder and aspen wood for the production of wood-based composite, specifically the production of OSB. It uses the experimental analysis carried out to evaluate the applicability for sheating materials of timber frame structures. First section reviews particleboard with a focus on OSB. It summarises the importance, use and production of OSB panels and focuses on alternative raw material types for the production of wood-based composites. Describes the various technological processes involved in the production of OSB. The second part focuses on the individual production operations and shows the measurement procedures carried out. It also illustrates the determined data and the statistical methods applied to them. Based on the statistically processed data of selected physical and mechanical properties of the manufactured boards, it compares and evaluates the determined values with the requirements specified in standard ČSN EN 300, corresponding to the given application.
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Evaluation of selected properties of mineral fibers-based board, including the design of suitable purposes of its application
Sýkora, Radim ; Böhm, Martin (advisor) ; Múčka, Martin (referee)
This thesis evaluates properties of board based on mineral fibers. In first part of the thesis is conducted analysis of the literature, where are described materials based on basalt fibers. Here is also explained production of basalt fiber and its practical applications. Sandwich materials and materials with great fire resistance based on wood are also looked into. Following part describes options of aplication of materials with great fire resistance and mechanical a physical properties of materials based on wood.
Second part of the thesis lays out methodical approach to individual performed mechanical and physical tests. Characteristic of examined material is included. The last part deals with test results, comparing results with other selected materials, debating results and proposing possible applications of examined basalt board. With use of found data is evaluated suitability of the material for use for construction of sandwich panel.
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Hybrid dental composites combining short fibers and particulate fillers
Klieštiková, Nikola ; Přikryl, Radek (referee) ; Bystřický, Zdeněk (advisor)
This work deals with the hybrid composite material combining particulate filler with short fibers for dental applications. The barium micro-filler and the short glass fibers were treated with -methacryloxypropyltrimethoxysilane in cyclohexane using n-propylamine. The barium micro-filler and the short glass fibers were mixed with the matrix based on a dimethacrylate resin. The effects of the addition of short glass fibers on mechanical properties were studied. Surface treatment of the filler was characterized by thermogravimetric analysis (TGA) and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). Fracture surfaces and the adhesion to the matrix was observed by scanning electron microscope (SEM). The modulus of elasticity and strenght was determined by three point bending flexural test. Critical values of the stress intensity factor annd energy release rate were determined using the three point bending flexural test of notched specimens. The particulate filler increased the flexural modulus of elasticity and fragility. The addition of short fibers had little effect on flexural modulus of elasticity, but increased the flexural strength and fracture toughness of the specimen.
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