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Modification of PLA using reactive extrusion
Matláková, Jana ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
Diplomová práce se zabývá roubováním maleinanhydridu a anhydridu kyseliny itakonové na kyselinu poly(mléčnou) (PLA). U modifikované kyseliny poly(mléčné) byla sledována závislost konverze monomerů na různých molárních poměrech monomer/iniciátor při teplotách 180°C a 200°C. Množství naroubovaného monomeru bylo stanovováno acidobazickou titrací a pomocí FT-IR spektroskopií. Vliv stupně naroubování na krystalinitu modifikované PLA byl zjišťován pomocí diferenční kompenzační kalorimetrie, DSC. Degradace PLA byla orientačně pozorována pomocí indexu toku taveniny, MFI.
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Analytical Methods of Radical Grafted Polypropylene
Zahálka, Martin ; Petruš, Josef (referee) ; Kučera, František (advisor)
The bachelor thesis deals with characterization and analyzes of radical grafted polypropylene. Analytical methods and processes used for determination of concentration of MA in grafted PP and characterization of prepared material were summarized in theoretical part. PP-g-MA samples were prepared by the homogeneous and heterogeneous technique. All the samples with unknown content of MA were analyzed by two volumetric methods. Quantitative analysis by attenuated total reflectance infrared spectroscopy (ATR–FTIR) was used. Carbonyl index was determined based on peaks of methylene (1167 cm-1) and carbonyl (1785 cm-1) groups. X-ray photoelectron spectroscopy was one of the methods used to determine concentration of MA in modified PP. Melt flow index was determined and range of -scission was discussed.
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Functionalization of Polypropylene by Maleimides
Korčušková, Martina ; Petruš, Josef (referee) ; Kučera, František (advisor)
Diploma thesis deals with preparation of polypropylene functionalized by maleimides, based on the reaction between maleic anhydride and amine. The overview of functionalization of polypropylene by maleic anhydride by reactive extrusion and routes for the synthesis and utilization of maleimides are contained in the theoretical part. Samples of maleimide-functionalized polypropylene were prepared by reactive extrusion using low molecular weight amines (aniline and 4-aminophenol) and hight molecular weight polyether monoamines. Functionalized polypropylene samples were prepared by several methods differing in the composition of the reaction mixture and performing a grafting reaction. Appropriate maleamic acids and maleimides were synthesized from low molecular weight amines and further used to functionalize the polypropylene. To characterize the samples, the degree of monomer conversion and melt flow index were determined and further analyses were performed by Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. The synthesis of low molecular weight products was further monitored by thin layer chromatography and thermogravimetric analysis with evolved gas analysis.
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Heterogeneous Radical Modification of Polypropylene
Brňák, Matúš ; Petruš, Josef (referee) ; Kučera, František (advisor)
The diploma thesis deals with the heterogeneous technique of preparation of grafted polypropylene g maleic anhydride (PP-g-MAH). The knowledge of the course of the reaction and its impact on the PP grafting process are summarized in the theoretical part. The preparation of the grafted PP was carried out in a fluidized polymerization reactor at 115 °C, speed of mixing 210 rpm, reaction time 60 min and pressure 6 bar. The amount of grafted MAH was monitored by using a MAH concentration 3 and 5 wt% and an initiator concentration 0.25; 0.5; 1; and 1.5 wt%. Modification efficiency was compared by using 3 types of PP with different particle morphology and specific surface area. By creating the theoretical model, the maximum surface concentration of MAH was calculated and compared with experimental data. Characterization of PP materials was performed by Electron Scanning Microscopy (SEM), Differential Scanning Calorimetry (DSC) and particle surface analysis by BET. Quantitative analysis of grafted MAH was determined by FTIR spectroscopy and acid-base titration.
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Functionalization of polyolefins by grafting
Paulenka, Igor ; Petruš, Josef (referee) ; Petrůj, Jaroslav (advisor)
The theoretical part of the diploma thesis is focused on the funcionalization of polyolefins in order to accelerate their degradation and to increase their carbon content from renewable resources with focus on hydroxyacids. The experimental part is focused on preparing samples and studying the properties of the polypropylene and polyethylene blends with the polylactide with different contents of the initiator and the maleic anhydride. Samples were evaluated by determining the degree of conversion maleic anhydride, differential scanning calorimetry, infrared spectroscopy, melt flow index and mechanical properties.
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Reactive Modification of Polypropylene
Matláková, Jana ; Žídek, Jan (referee) ; Lehocký, Marián (referee) ; Kučera, František (advisor)
The theoretical part describes the principles of the free-radical induced grafting and the influence of various parameters on the reactions course. The literature research summarizes the latest knowledge in the field of the reactive modification of polypropylene (PP), it is mainly focused on the PP modification using an unsaturated acid anhydrides. Theoretical part describes the various procedures and modification of technology in order to increase the grafting yield of maleation. The experimental part is determined by the influence of the stabilizers concentration, the peroxide structure, and the binary mixture of monomers on the grafting yield and the reaction course. In the first part, the critical stabilizers concentration was determined based on the experimentally obtained relationship between the grafting yield and the stabilizers concentration. A kinetic schema of grafting of MAH onto PP in the presence of stabilizers has been proposed and compared with the experimental results. The effect of the stabilizers on the extent of the undesirable b-scission was evaluated based on the melt flow rate (MFR) and the rheological curves of PP-g-MAH. In the second part, the effect of the peroxide structure and the concentration of reactants on the grafting yield of PP modification with MAH and itaconic anhydride (IAH) was observed. The initial grafting yield Rg has been experimentally determined and compared with a defined area of theoretical values of Rg. The extent of b-scission was significantly influenced by the structure and the concentration of peroxide, as shown by the results of MFR and the rheological curves of PP-g-MAH. The last part of the doctoral thesis is focused on the assessment of the combination of MAH and IAH as comonomers on the grafting yield. At first, the reference polymers were prepared using the solution polymerization of MAH, and IAH, and copolymerization of MAH with IAH. The reference polymers were analyzed by FTIR, DSC, WAXS to confirm the probable copolymerization of MAH and IAH. The dependence of the reaction enthalpy on the reaction time was observed using simulations of bulk polymerization of MAH, IAH and mixtures MAH and IAH "in situ" in isothermal calorimeter. PP was subsequently modified with a combination of MAH and IAH as comonomers in order to assess its effect on the grafting yield
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Functionalization of Polypropylene by Maleimides
Korčušková, Martina ; Petruš, Josef (referee) ; Kučera, František (advisor)
Diploma thesis deals with preparation of polypropylene functionalized by maleimides, based on the reaction between maleic anhydride and amine. The overview of functionalization of polypropylene by maleic anhydride by reactive extrusion and routes for the synthesis and utilization of maleimides are contained in the theoretical part. Samples of maleimide-functionalized polypropylene were prepared by reactive extrusion using low molecular weight amines (aniline and 4-aminophenol) and hight molecular weight polyether monoamines. Functionalized polypropylene samples were prepared by several methods differing in the composition of the reaction mixture and performing a grafting reaction. Appropriate maleamic acids and maleimides were synthesized from low molecular weight amines and further used to functionalize the polypropylene. To characterize the samples, the degree of monomer conversion and melt flow index were determined and further analyses were performed by Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. The synthesis of low molecular weight products was further monitored by thin layer chromatography and thermogravimetric analysis with evolved gas analysis.
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Heterogeneous Radical Modification of Polypropylene
Brňák, Matúš ; Petruš, Josef (referee) ; Kučera, František (advisor)
The diploma thesis deals with the heterogeneous technique of preparation of grafted polypropylene g maleic anhydride (PP-g-MAH). The knowledge of the course of the reaction and its impact on the PP grafting process are summarized in the theoretical part. The preparation of the grafted PP was carried out in a fluidized polymerization reactor at 115 °C, speed of mixing 210 rpm, reaction time 60 min and pressure 6 bar. The amount of grafted MAH was monitored by using a MAH concentration 3 and 5 wt% and an initiator concentration 0.25; 0.5; 1; and 1.5 wt%. Modification efficiency was compared by using 3 types of PP with different particle morphology and specific surface area. By creating the theoretical model, the maximum surface concentration of MAH was calculated and compared with experimental data. Characterization of PP materials was performed by Electron Scanning Microscopy (SEM), Differential Scanning Calorimetry (DSC) and particle surface analysis by BET. Quantitative analysis of grafted MAH was determined by FTIR spectroscopy and acid-base titration.
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Analytical Methods of Radical Grafted Polypropylene
Zahálka, Martin ; Petruš, Josef (referee) ; Kučera, František (advisor)
The bachelor thesis deals with characterization and analyzes of radical grafted polypropylene. Analytical methods and processes used for determination of concentration of MA in grafted PP and characterization of prepared material were summarized in theoretical part. PP-g-MA samples were prepared by the homogeneous and heterogeneous technique. All the samples with unknown content of MA were analyzed by two volumetric methods. Quantitative analysis by attenuated total reflectance infrared spectroscopy (ATR–FTIR) was used. Carbonyl index was determined based on peaks of methylene (1167 cm-1) and carbonyl (1785 cm-1) groups. X-ray photoelectron spectroscopy was one of the methods used to determine concentration of MA in modified PP. Melt flow index was determined and range of -scission was discussed.
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Functionalization of polyolefins by grafting
Paulenka, Igor ; Petruš, Josef (referee) ; Petrůj, Jaroslav (advisor)
The theoretical part of the diploma thesis is focused on the funcionalization of polyolefins in order to accelerate their degradation and to increase their carbon content from renewable resources with focus on hydroxyacids. The experimental part is focused on preparing samples and studying the properties of the polypropylene and polyethylene blends with the polylactide with different contents of the initiator and the maleic anhydride. Samples were evaluated by determining the degree of conversion maleic anhydride, differential scanning calorimetry, infrared spectroscopy, melt flow index and mechanical properties.
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