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Preparation of PP composites by grafting using monomer treated filler
Kramerová, Nina ; Žídek, Jan (referee) ; Kučera, František (advisor)
Bachelor thesis is focused on preparation of composite materials with polypropylene matrix. The composites were prepared “in situ” with using Brabender mixer. Homogenization of matrix and filler and grafting of PP with anhydride of itaconic acid treated filler proceed together according to radical mechanism of polymerization. Luperox 101 [2,5-dimethyl-2,5-di(tertbutyl-peroxy)hexane] was used as an initiator of the reaction, the concentration of the initiator was 0.5 wt %, processing temperature 210 °C, 30 rpm. PP-g-IA is a compatibilizer between the matrix and the filler. Glass fibers, calcite and two types of ground wood pulp were used as filler. Two analytical methods were chosen to analyze the efficiency of grafting, acid-base titration and infrared spectroscopy. Assigned conversion of monomer was from 42 to 87 % for various fillers.
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Functionalization of Polypropylene by Grafting
Kelíšek, Petr ; Sadílek, Jiří (referee) ; Petrůj, Jaroslav (advisor)
This bachelor thesis deals with the study of functionalization of polypropylene by grafting. The theoretical part summarizes current knowledge about the properties of polypropylene, polylactic acid, radical grafting, factors influencing the properties of such functionalized polymer and modification of immiscible polymers by the aid of compatibilizer. In the experimental part, samples of polypropylene grafted with polylactic acid, and blends of polypropylene with polylactic acid were prepared on an internal mixer under different conditions. Temperature and torque were monitored during the mixing. Created materials were evaluated by comparing their base properties (tensile strength, melt flox index).
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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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Grafting of PP using itaconic anhydride and drying agent
Petruš, Josef ; Hermanová, Soňa (referee) ; Kučera, František (advisor)
The bachelor´s thesis deal with a preparation of polypropylene (PP) grafted with itaconic acid (IA) and itaconic anhydride (IAH) arising by thermic dehydration in situ from IA in presence of drying agents. Theoretical part contains actual knowledges especially about radical grafting of polypropylene with different monomers. In experimental part samples of polypropylene grafted with 0.5 wt % IA were prepared with free different drying agents: calcium oxide, aluminium oxide and calcium sulfate hemihydrate. To comparison PP grafted with 0.5 wt % IAH was prepared. Thermic behaviour of IA with drying agent and IAH samples was determined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurement. Process of grafting was realized with mixer Brabender at temperature 230 °C, speed was 30 RPM and reaction time 6 minutes. 2,5-dimethyl-2,5bis(tert-buthylperoxy)hexane (Luperox 101) was used as iniciator. Percentage of grafted carboxylic groups was provided by acid-base titration. FTIR spectroscopy was used for quantitative and qualitative analysis of characteristic groups.
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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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PP/PA6 polymer blend preparation
Olšan, Jakub ; Petruš, Josef (referee) ; Kučera, František (advisor)
Bachelor’s thesis studies preparation of polymer blends of polyamide 6 with polypropylene. A present knowledge about preparation of polymer blend of PA6/PP was summarized in theoretical part. Experimental part is focused on an ideal ratio of starting materials for compounding to get maximal elongation at break. At first the preparation of samples was realised in Brabender mixer at temperature of 240 °C, reaction time 6 minutes and 50 RPM. Later, samples were prepared in double-screw extruder at temperature zones between 220 and 240 °C, transition time 3,5 minutes and 90 RPM. All samples were measured on melt flow rate and tensile test. Morfology was studied by SEM. Due to SEM it was discovered that there is huge difference between compatibilized and uncompatibilized blends in their morfology. Thanks to FTIR and DSC it was proved that there is chemical bond between PA 6 and compatibilizer. Conditionation of this exact blend was done to discover the influence on mechanical properties.
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Preparation of grafted PP with diferent concentration of MA and IA
Běťák, Lukáš ; Žídek, Jan (referee) ; Kučera, František (advisor)
The bachelor thesis deal with a preparation and a characterization of polypropylene grafted with anhydrides carboxylic acids in a melt. A present knowledge about radical grafting was summarized in a theoretical part. Samples of polypropylene grafted with itaconic anhydride (IA) and maleic anhydride (MA) were prepared in the experimental part. 2,5 dimethyl 2,5bis(tert-buthylperoxy)hexane (Luperox 101) was used as a radical initiator. A Brabender mixer was used for experiment, conditions for grafting were 210 °C, 30 RPM and 6 min. Weight concentration of grafted monomer was in range 0,25 wt % 1 wt %. It was found that a degree of conversion depended on concentration ratio of initiator to monomer. Attached carboxylic groups to polypropylene backbone were confirmed by FTIR spectroscopy. The percentage of grafting was determined by acid-base titration.
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Modification of Polyethylene by Reactive Compounding
Horkel, Ondřej ; Kučera, Jaroslav (referee) ; Petrůj, Jaroslav (advisor)
This Master’s thesis deals with the problematics of radically initiated compounding of polyethylene by 1-vinyladamantane. Theoretical part focuses on the theory of grafting processes and how they are influenced by chosen process parameters, as well as the properties of used monomer. In experimental part, two sets of experiments were designed, in both cases the chemicals used were polyethylene LITEN MB 87, (2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane), also called Trigonox 101, as the initiator, and chemicals called Ionol and Irgafos 168 as stabilizers. The experiments were carried out in a Brabender batch mixer, the temperature was 180 – 185 °C, the reaction time was 5 minutes. The analytic methods used to evaluate the prepared samples’ properties were the tensile testing, the Charpy notch test, measuring of the melt flow index, analyzing the torque during kneading and the analysis of infrared spectra of the samples. By carrying out of these experiments it was found that excessive crosslinking was present with mass fraction of initiator being as low as 2 %. It was also concluded that under these conditions the modification does not improve tensile properties of the material, but it does improve the impact strength, albeit slightly. The influence of the modification on flow properties needs to be investigated further. A presence of vinyl groups was observed in infrared spectra, suggesting the presence of ungrafted vinyladamantane.
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Grafting VTMOS onto PHB
Novotný, Igor ; Petruš, Josef (referee) ; Kučera, František (advisor)
Diploma thesis deals with the grafting of vinyltrimethoxysilane (VTMOS) onto poly(3–hydroxybutyrate)PHB. Subsequent characterization of the amount of grafted VTMOS and changes in the thermal properties associated with the rate of crystallization. The theoretical part deals with mechanism and the influences of grafting. In the experimental part VTMOS was grafted onto PHB without subjecting VTMOS to hydrolysis and subsequent crosslinking. By differential scanning calorimetry (DSC) and Avrami equation, the effect of grafted silane group on pure was studied. The MVR was used to compare the rheological properties of initial PHB, grafted PHB and crosslinked PHB by siloxane linkages.
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