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Modification of polymer blends based on polyhydroxybutyrate and their properties
Melčová, Veronika ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
Teoretická část této diplomové práce popisuje vlastnosti a možnosti modifikace poly(3-hydroxybutyrátu) (PHB) a amorfní poly(mléčné kyseliny) (PLA) a jejich směsí. V experimentální části je studována reaktivita Joncrylu, Raschigu a fosfitových činidel trifenylfosfitu, tris(nonylfenyl) fosfitu a difenylisodecylfosfitu s čistým PLA a PHB. Raschig, oligomerní aditivum na bázi polykarbodiimidu, prokázal v množství 2hm. % zvýšení viskozity taveniny obou polymerů, a proto byl použit k přípravě směsí o pěti hmotnostních poměrech PHB/(PHB+PLA). Vzorky s Raschigem a odpovídajícími nereaktivními vzorky byly studovány pomocí reologie, gelové permeační chromatografie a modulované diferenční kompenzační kalorimetrie. Výsledky naznačily reakce Raschigu v PHB/PLA směsích vedoucí k rozvětveným strukturám. Rychlost reakce však není nedostatečná ke kompenzaci poklesu viskozity v důsledku degradace při zpracování. Následně zůstává nezreagované množství Raschigu v matrici. Na základě těchto zjištění se dospělo k závěru, že Raschig se chová spíše jako relativně účinný stabilizátor reologických vlastností, než jako činidlo pro záměrnou modifikaci struktury směsí PHB/PLA. Za účelem studia mechanických vlastností těchto směsí byly ve dvoušnekovém extrudéru připraveny vzorky plastifikovány acetyltributylcitrátem.
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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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Technological optimization of a pilot line for production PP-g-IAH
Arvai, Tomáš ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The bachelor thesis deals with optimization of a pilot line for production polypropylene grafted with itaconic anhydride. Theoretical part describes actual knowledge about radical grafting of polyolefins with emphasis on the variety of factors affecting melt grafting. Extruded mass per hour, torque and die pressure were measured during all extrusions within optimization. Two sets of samples were prepared in the co-rotating twin-screw extruder (Brabender 25 DSE L/D = 34). Sample set prepared at 200 °C ranged from 1:2 to 1:20 molar ratio of initiator/monomer, set prepared at 230 °C ranged from 1:4 to 1:20 molar ratio. Parameters set for all extrusions were 30 RPM, reaction time 3 minutes. All samples contained the same mass concentration of monomer 0.5 %, initiator selected 2,5-di(tert-butylperoxy)-2,5-dimethylhexane (Luperox 101). Degradation of samples was observed through MVR measurements, monomer content in extruded samples was analyzed by acid-base titration and FT-IR spectroscopy.
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Reactive extrusion of polymers by peroxides
Červený, Ladislav ; Petruš, Josef (referee) ; Kučera, František (advisor)
Diploma thesis deals with processing of two types of PP, HDPE, LDPE, PET, PA, PS, PMMA and ABS by reactive extrusion in presence of peroxides. The theoretical part summarizes existing knowledge about processing of used polymers. Reactive extrusion was carried out with a single screw extruder at 260 °C, 30 rpm and 60 rpm depending on peroxide used. One type of PP was processed in presence of Luperox 101, hydrogen peroxide, dicumyl peroxide and potassium persulfate. Luperox 101 and hydrogen peroxide were chosen for reactive extrusion of other polymers. The efficiency of selected peroxides on radical modifications of individual polymers during processing was evaluated by methods of rheological (MFI), structural (FTIR) and thermal (DSC) analysis.
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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 materials based on reactive modified polyolefins
Běťák, Lukáš ; Žídek, Jan (referee) ; Kučera, František (advisor)
This thesis deals with a preparation of modified polypropylene. Modified polypropylene was prepared by reaction itaconic anhydride and compounds contain primary and secondary amino group (diaminododecane, aminoethylethanolamine and aminoethylpiperazine). Knowledge of radical and condensation modification of polypropylene were summarized in the theoretical part. New application of modified polypropylene ware summarized at the theoretical part as well. In the experimental part polypropylene was functionalized by grafting with itaconic anhydride during reactive extrusion. Extrusion was carried on the co-rotating twin-screw extruder (Brabender 25 DSE L/D = 34) at 230 °C and 30 RPM. Residence time of reactive blend was 3 minutes. The modified polypropylene PP-g-IAH) contained 0.5 wt% of itaconic anhydride. 2,5 dimethyl 2,5bis(tert buthyl-peroxy)hexane (Luperox 101) was used as a radical initiator. A ratio initiator/monomer was 1:0.6 (mol/mol). PP-g-IAH was used for condensation reaction with amino compounds in molar ratios IAH/amine from 1:0,3 to 1:1. This reaction carried out in single screw extruder (Betol 1825 L/D = 39) at 210 °C and 30 RPM. Residence time of reactive blend was 3 minutes. Fourier transform infrared spectroscopy was used for a calculation of reaction conversion and for description of new functional groups in the materials. This analysis confirmed the presence of amide and imide groups in the samples. Influence of amino compounds to polymer crystallinity was studied by differential scanning calorimetry. Termogravimetric analysis focused on thermal stability of prepared samples and changes of thermal stability was observed in dependence of additives amount. The rheological behaviors of modified PP were analyzed by measuring the complex viscosity.
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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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Imidation of cyclic anhydrides and modified polyolefins
Šimonek, Michal ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The main focus of the presented bachelor’s thesis is on the reaction pathway that leads to the formation of cyclic imides and utilizing imidation as a way to modify polyolefins. The theoretical part serves as a summary of relevant information concerning the formation of imides, functionalization of polyolefins via radical-induced grafting, and exploitation of reactions between anhydride-modified polyolefins and various amines. The specificity of amic acid formation was tested via reactions of succinic acid and ammonia in different molar ratios. Suitability of succinamic acid and its ammonium salt to give succinimide was evaluated. Similarly, N-substituted succinamic acid and succinimide were prepared from commercial amine, Elastamine RE1-2007, and succinic acid. Imide modified polyolefins were prepared firstly by a reaction in a solution of toluene, secondly in the melt in Brabender laboratory kneader at 60 and 120 rpm respectively, reaction temperature of 190 °C and reaction time of 16 minutes. The presence of expected groups in all samples was determined by FT-IR spectrometry. Modified polyolefins from the reaction in a solution were analysed by DSC and TGA to determine suitable reaction temperature for experiments in the melt. Kneader torque traces were examined to characterize mixing during reactions in the melt state.
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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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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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