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Properties of fibers based on polyhydroxybutyrate
Štulrajterová, Lujza ; Tocháček, Jiří (oponent) ; Přikryl, Radek (vedoucí práce)
This work deals with the melt spinning process of biopolymer fibers. Recent knowledge of poly(3-hydroxy butyrate) (PHB) and poly(lactic acid) (PLA) fiber spinning processes have been covered in the theoretical part. PHB based polymer blends of various composition were prepared to study the effect of PLA, different plasticizers and their content on the fiber properties. Three commercial plasticizers (ATBC, PEG, A6) and two experimentally synthesized were used. Spinning was carried out on three devices. Spinning on the conventional spinning lines with take-up speed exceeding 150 m/min was not accomplished. Lowe take-up speed was necessary due to insufficient melt strength. Fibers with drawing ratio of 6.4 were prepared and analyzed by GPC, MDSC and mechanical testing. According to the glass transition temperature results, ATBC and PEG have better plasticizing effect over the studied PLA/PHB blends than A6. Fibers containing A6 have the highest tensile strength and modulus of elasticity of 250 MPa and 2.7 GPa, respectively. At last, the effect of aging, thermal and hydrothermal treatment on mechanical properties of fibers was studied.
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Plasma surface modification of powder fillers
Štulrajterová, Lujza ; Bystřický, Zdeněk (oponent) ; Přikryl, Radek (vedoucí práce)
This bachelor’s thesis deals with the study of particulate-filled composite materials and the influence of filler surface modifications on the properties of the composite. Important aspects of particulate fillers, used fillers and possible surface treatments were characterized in the theoretical section of this work. Dimethacrylate matrix with halloysite nanotubes as filler was chosen as a studied system. The filler was modified by low-temperature plasma under low pressure and by silanization. Surface of the modified filler was studied by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Particle size distribution was measured by photon cross-correlation spectroscopy and dynamic light scattering (DLS). Mechanical properties of prepared particulate composites were established by the testing of the flexural properties. Fracture areas were analyzed by using scanning electron microscopy (SEM). The results showed no effects of the plasma treatment on the mechanical properties. Silane treatment of the filler surface illustrated improvement of the composite material strength.
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Properties of fibers based on polyhydroxybutyrate
Štulrajterová, Lujza ; Tocháček, Jiří (oponent) ; Přikryl, Radek (vedoucí práce)
This work deals with the melt spinning process of biopolymer fibers. Recent knowledge of poly(3-hydroxy butyrate) (PHB) and poly(lactic acid) (PLA) fiber spinning processes have been covered in the theoretical part. PHB based polymer blends of various composition were prepared to study the effect of PLA, different plasticizers and their content on the fiber properties. Three commercial plasticizers (ATBC, PEG, A6) and two experimentally synthesized were used. Spinning was carried out on three devices. Spinning on the conventional spinning lines with take-up speed exceeding 150 m/min was not accomplished. Lowe take-up speed was necessary due to insufficient melt strength. Fibers with drawing ratio of 6.4 were prepared and analyzed by GPC, MDSC and mechanical testing. According to the glass transition temperature results, ATBC and PEG have better plasticizing effect over the studied PLA/PHB blends than A6. Fibers containing A6 have the highest tensile strength and modulus of elasticity of 250 MPa and 2.7 GPa, respectively. At last, the effect of aging, thermal and hydrothermal treatment on mechanical properties of fibers was studied.
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Plasma surface modification of powder fillers
Štulrajterová, Lujza ; Bystřický, Zdeněk (oponent) ; Přikryl, Radek (vedoucí práce)
This bachelor’s thesis deals with the study of particulate-filled composite materials and the influence of filler surface modifications on the properties of the composite. Important aspects of particulate fillers, used fillers and possible surface treatments were characterized in the theoretical section of this work. Dimethacrylate matrix with halloysite nanotubes as filler was chosen as a studied system. The filler was modified by low-temperature plasma under low pressure and by silanization. Surface of the modified filler was studied by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Particle size distribution was measured by photon cross-correlation spectroscopy and dynamic light scattering (DLS). Mechanical properties of prepared particulate composites were established by the testing of the flexural properties. Fracture areas were analyzed by using scanning electron microscopy (SEM). The results showed no effects of the plasma treatment on the mechanical properties. Silane treatment of the filler surface illustrated improvement of the composite material strength.
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