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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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Radical grafting of PE/PP copolymer
Šido, Jiří ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
Diploma thesis deals with preparation and characterization of block copolymer PP/PE grafted with itaconic anhydride in melt. Experimental part deals with free radical iniciated grafting of polar monomers onto polyolefins and with potencial applications of grafted polyolefins. Samples of PP/PE grafted with itaconic anhydride were prepared under various conditions in the experimental part. 2,5-dimethyl-2,5bis(tert-buthylperoxy)hexane (Luperox 101) was used as radical iniciator. Grafting was performed in Brabender mixer under conditions: temperature 190-230°C, concentration of monomer 0,25-1 weight percent, concentration of iniciator 0,025 – 2 weight percent, screw speed 30 rpm. The influence of certain parameteres: iniciator concentration, monomer concentration and temperature upon conversion of monomer, value of MFI and homopolymerization of monomer extent was of interest. Presence of anhydride bonded to the polymer backbone was confirmed by FTIR spectroscopy. Concentration of grafted anhydride and conversion of monomer was determined by acid-base titration and confirmed by FTIR spectroscopy.
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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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Grafting of polypropylene with derivatives of itaconic acid
Poštulková, Hana ; Běťák, Lukáš (referee) ; Kučera, František (advisor)
Bachelor thesis deals with grafting of polypropylene (PP) by using derivatives of itaconic acid (IA) in the melt phase, specifically with monomethyl itaconate (MMI) and dimethyl itaconate (DMI). Theoretical part focuses on summary of radical initiated grafting of PP with different monomers especially DMI and MMI and factors influencing radical grafting. In experimental part were prepared samples with concentration of monomer 1-5 wt. % and concentration of initiator 1,5-0,15 wt. %. Influence of concentration of monomer, ratio of monomer concentration to initiator concentration and temperature on concentration of grafted monomer and conversion were determined. A Brabender mixer was used for all experiments. Conditions of grafting were 75 rpm, time of reaction 6 minutes and temperature 180-200 °C, initiator Luperox 101. Degradation of polymer chain was determined by MFI. Infrared spectroscopy (FTIR) was used to calculate monomer conversion and concentration of grafted monomer.
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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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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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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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New methods of grape-vine (Vitis vinifera) plants production
ZUKAL, Radim
My bachelor work deals with the description methods of the propagation of grapevine. Vine can be reproduce vegetatively and generatively. In a generative propagation is described tree breeding maintenance and tree breeding of new varieties. Vegetative propagations deals with the propagation of direct, indirect propagation and propagation in vitro. Described is also a technology of producing grapevine plants.
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Cristates shapes grafting of selected cactuses species
BORDOVSKÁ, Monika
Fasciation is the deviation of plant growth, which penetrate the cristates. Their reproduction is easiest grafting. Between 2008 and 2009, always in late May, was based grafting experiments. The grafting was used in each year of the 5 kinds of rootstocks. On all rootstocks were grafted Christ in each year a different kind. In each year, so was the 100 grafted plant (total 200). Slips were used as cristate Cleistocactus sp. and Hildewintera aureispina as rootstocks and cacti Cereus jamacaru, Cereus peruvianus Echinopsis eyriesii, Echinopsis huascha, Eriocereus jusbertii, Trichocereus pasacana. The highest average success rate of grafting, the rootstock had Echinopsis hauscha (57.5%). The worst results are showing the type of rootstock Cereus jamacaru (5%). Overall, the successful grafting cristata Hildewintera aureispina 49%. The highest grafting success was achieved rootstocks Echinopsis eyriesii when it was grafted Christ Cleistocactus sp. (65%). The highest average success rate (of all types of cristates) had a rootstock Echinopsis hauscha (57.5%).
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