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The influence of detergents on time to failure of high density polyethylene by full notch creep test performed in corrosive bath
Kotoučková, Simona ; Tocháček, Jiří (referee) ; Bálková, Radka (advisor)
The thesis deals with the study of the influence of concentration and different types of surfactants (Igepal CO-520, Arkopal N110, Igepal CO-890, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, dodecyltrimethylammonium bromide and Dehyton PL) on the environmental stress cracking resistance of high-density polyethylene by means of Full Notch Creep Test. Furthermore, the influence of ligamental stress (3,5; 4,0 a 4,5 MPa), pH of the prepared active environment and type of the water used as a solvent for the surfactants on the time to failure was monitored. An accelerating effect was observed at increased concentration, stress and molecular weight. Faster failure was achieved after exposure to ionic types compared to nonionic. The rate of the notch opening was determined. The brittle and ductile behavior during the process of failure was evaluated by microscopic analysis of the morphology of the fracture surfaces. Based on the pH change after the test, the stability of the active environment was evaluated. Deteriorating quality of surfactant solutions was observed. Raman spectroscopy and Fourier transform infrared spectroscopy were used to detect the surfactant on the surface of the test specimen after the test.
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Study of relation between conditions of the test FNCT (Full Notched Creep) and the rate of crack grow SCG (Slow Crack Growth) for evaluating HDPE cut growth resistance
Porubský, Tomáš ; Sadílek, Jiří (referee) ; Petrůj, Jaroslav (advisor)
Theoretical part of this thesis presents summary of material and testing parameters which influence SCG and consequently the duration of the FNCT test. The experimental part focuses on modification of testing conditions of FNCT test in order to minimize the test time. FNCT tests were performed for four types of surfactants: Arkopal N110, Sodium dodecylbenzensulfonate (NaDBS), Disponil LDBS55 and Simulsol SL8. The most pronounced accelerating effect was observed for NaDBS surfactant, which in comparsion with commonly used Arkopal N110 doubled the test speed at the same concentration (11 %) and other test conditions. The accelerating effect of NaDBS was also observed for two different PE grades: Liten VB85 and VL 20N. Under the test conditions 80 °C and 4 MPa, 5% NaDBS water solution caused for VL 20N almost 12,5-fold acceleration compared to conventional 2% Arkopal N110 and almost 8,5-fold acceleration for VB 85. The correlation between wettability of surfactant solution and FNCT time to fracture was found.
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Study of conditions influence on the rate of crack propagation in HDPE
Patzelt, Petr ; Kučera, Jaroslav (referee) ; Petrůj, Jaroslav (advisor)
Theoretical part of the thesis is aimed on the summary of material and testing parameters that influence SCG process and also the duration of FNCT test. The experimental part deals with the comparison of time to crack between two used surfactants – 2% Arkopal N110 and 10% sodium dodecylbenzenesulfonate. The temperature during the experiments was 80 °C. The acceleration of the process influenced by solution of sodium dodcelbenzenesulfonate was many times higher against solution of Arkopal. There were tested several HDPE and PP specimens to prove this phenomenon. HDPE specimens used – VB85, VL 20N, PL 10 that were made in UNIPETROL RPA and some other competitive materials were used. PP specimens were developed in labs of Polymer Institute Brno. In additional, another experimental part focuses on evolving the math definition of curves measured within FNCT tests and it is still in progress.
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The influence of detergents on time to failure of high density polyethylene by full notch creep test performed in corrosive bath
Kotoučková, Simona ; Tocháček, Jiří (referee) ; Bálková, Radka (advisor)
The thesis deals with the study of the influence of concentration and different types of surfactants (Igepal CO-520, Arkopal N110, Igepal CO-890, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, dodecyltrimethylammonium bromide and Dehyton PL) on the environmental stress cracking resistance of high-density polyethylene by means of Full Notch Creep Test. Furthermore, the influence of ligamental stress (3,5; 4,0 a 4,5 MPa), pH of the prepared active environment and type of the water used as a solvent for the surfactants on the time to failure was monitored. An accelerating effect was observed at increased concentration, stress and molecular weight. Faster failure was achieved after exposure to ionic types compared to nonionic. The rate of the notch opening was determined. The brittle and ductile behavior during the process of failure was evaluated by microscopic analysis of the morphology of the fracture surfaces. Based on the pH change after the test, the stability of the active environment was evaluated. Deteriorating quality of surfactant solutions was observed. Raman spectroscopy and Fourier transform infrared spectroscopy were used to detect the surfactant on the surface of the test specimen after the test.
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Study of conditions influence on the rate of crack propagation in HDPE
Patzelt, Petr ; Kučera, Jaroslav (referee) ; Petrůj, Jaroslav (advisor)
Theoretical part of the thesis is aimed on the summary of material and testing parameters that influence SCG process and also the duration of FNCT test. The experimental part deals with the comparison of time to crack between two used surfactants – 2% Arkopal N110 and 10% sodium dodecylbenzenesulfonate. The temperature during the experiments was 80 °C. The acceleration of the process influenced by solution of sodium dodcelbenzenesulfonate was many times higher against solution of Arkopal. There were tested several HDPE and PP specimens to prove this phenomenon. HDPE specimens used – VB85, VL 20N, PL 10 that were made in UNIPETROL RPA and some other competitive materials were used. PP specimens were developed in labs of Polymer Institute Brno. In additional, another experimental part focuses on evolving the math definition of curves measured within FNCT tests and it is still in progress.
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Study of relation between conditions of the test FNCT (Full Notched Creep) and the rate of crack grow SCG (Slow Crack Growth) for evaluating HDPE cut growth resistance
Porubský, Tomáš ; Sadílek, Jiří (referee) ; Petrůj, Jaroslav (advisor)
Theoretical part of this thesis presents summary of material and testing parameters which influence SCG and consequently the duration of the FNCT test. The experimental part focuses on modification of testing conditions of FNCT test in order to minimize the test time. FNCT tests were performed for four types of surfactants: Arkopal N110, Sodium dodecylbenzensulfonate (NaDBS), Disponil LDBS55 and Simulsol SL8. The most pronounced accelerating effect was observed for NaDBS surfactant, which in comparsion with commonly used Arkopal N110 doubled the test speed at the same concentration (11 %) and other test conditions. The accelerating effect of NaDBS was also observed for two different PE grades: Liten VB85 and VL 20N. Under the test conditions 80 °C and 4 MPa, 5% NaDBS water solution caused for VL 20N almost 12,5-fold acceleration compared to conventional 2% Arkopal N110 and almost 8,5-fold acceleration for VB 85. The correlation between wettability of surfactant solution and FNCT time to fracture was found.
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