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Use of antimicrobial products of animal origin in cosmetics
Puškárová, Radka ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
The Bachelor thesis deals with characterization a whey in free and encapsulated form and its application to cosmetic industry. The theoretical part is focused on characterization of whey, especially on its antimicrobial properties, and use of this effect in selected cosmetics preparatives. Further, methods of encapsulation and particles characterization were described. In the experimental part, antimicrobial properties of whey were tested by two different methods. Whey was encapsulated into three different types of particles: liposomes, alginate and chitosan. Long-term colloid stability of particles during one and three weeks of storage in model conditions was tested. Further, particles were added into model skin creams. Long-term sedimentation stability of these emulsions was analyzed by analytical centrifuge.
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The Application of Separation Techniques Based on Gas and Liquid Chromatography with Different Types of Detectors for the Determination of Biologically Active Compounds and Selected Xenobiotics
Mravcová, Ludmila ; Hajšlová, Jana (referee) ; Kráčmar, Stanislav (referee) ; Chýlková,, Jaromíra (referee) ; Vávrová, Milada (advisor)
This work deals with the using and application of separation techniques for analysis of polymers degradation and polycyclic aromatic hydrocarbons. Thereby this work is separated to two special parts. In the first part, the degradation properties of synthetic biopolymers based on lactic acid, gylcolic acid and poly(ethyleneglycol) PLGA-PEG-PLGA and ITA-PLGA-PEG-PLGA-ITA (modified by itaconic acid) were studied. These copolymers (firstly their thermosensitive hydrogels) should be used for therapy of fractures in orthopedy (as adhesives). Therefore, the sol-gel and gel-sol phase diagrams were determinated for selected samples of copolymers. The samples forming gel at 37 C was used for other study. Polymer samples were depredated in phosphate buffer at 37°C. The degradation process of physical hydrogels was described by the decrease of molecular weight and the increase of concentration lactic acid and glycolic acid in phosphate buffer. The obtained results confirmed that the degradation of polymer modified by itaconic acid is faster process than no modified polymer and polymers with lower ratio PLGA/PEG degrade also faster than lower ration PLGA/PEG. The influence of pH it was also tested. The rate of degradation of polymers was follow pH 4,0
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The study of using lactic acid esters for preparing lactides and PLA
Vida, Mikuláš ; Figalla, Silvestr (referee) ; Petrůj, Jaroslav (advisor)
This diploma thesis deals with use of lactic acid esters for preparation of lactides and PLA. In the theoretical part, it has been processed literature review focus on manufacturing technologies and properties of lactic acid and its esters (especially ethyl ester and lactides). In the experimental part, it has been designed and realized functional laboratory apparatus for preparation of cyclic dimer of lactic acid – lactides. On this apparatus, there were carried out principal laboratory experiments leading to optimization of lactides yields using various catalysts.
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PLA Synthesis in Solution
Svítil, Jan ; Zdeněk, Přikryl (referee) ; Petrůj, Jaroslav (advisor)
This thesis is studying PLA syntheses using polymerization of lactides in solution. Theoretical part deals with properties and production of lactic acid, lactides and polylactides. In the experimental part, possibilities of lactides polymerization in solution has been summerised and verified. Syntheses were performed via “solvothermal” method using 7 solvents (toluene, chloroforme, 1,2-chlorobenzene, acetone, tetrahydrofurane, cyclohexane and hexane). Using hexane as solvent, at concentration ratio catalyzer/lactide 1 : 1 000, polymerization temperature 160 °C and reaction time 20 h, polylactide of viscosity average molecular weight 179 000 gmol–1 was synthetized from the lactide.
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New Processes of Lactid Acid Polymers Preparation
Figalla, Silvestr ; Svěrák, Tomáš (referee) ; Herink,, Tomáš (referee) ; Petrůj, Jaroslav (advisor)
The work focuses on new processes for the preparation of lactic acid derivatives. The main objective was to verify the feasibility of preparing high molecular weight polylactide using ethyl lactate as a precursor of lactide synthesis. Part of the work is devoted to the new ethyl lactate synthesis method. The experimental part of the thesis is divided into partial key steps on the way from the lactic acid to the high molecular polylactide. The preparation of anhydrous ethyl ester of lactic acid (EtLA) was solved in an innovative way using alcoholysis of the oligomeric lactic acid. A kinetic model for isothermal alcoholysis and equimolar reactants ratio was derived from this method. The ethyl lactate was oligomerized by transesterification into the low and high molecular weight oligomer with the help of newly found catalysts suitable for the reaction medium. Stannous lactate was used as catalyst for oligomerization of the low molecular weight polymer suitable for the preparation of lactide (Mn 1000 g.mol-1). Experimental polymerization of ethyl lactate into high molecular weight product in tens of kDa has been investigated with newly synthesized tetraethyllactoyl titanate, Ti(EtLA)4. The laboratory method was derived for the depolymerization of the oligomer into lactide. Optimal conditions found for lactidation are as follow: temperature 225 ° C, pressure 2 kPa, catalysis 0,05 mol% of stannous lactate (with respect to oligomer lactate units). The prepared lactide was refined to polymer grade purity by distillation and subsequent recrystallization from ethyl acetate and toluene. The method for the preparation of high molecular weight PLA through ROP polymerization of lactide has been optimized. By optimization, suitable catalyst concentration was found in combination with the polymerization temperature and the polymerization length. An equimolar mixture of Tin 2-ethylhexanoate and 1-decanol was used as the catalytic system. The optimal ROP conditions for achieving the maximum molecular weight and suppressed polymer coloration (yellowing) are: catalyst concentration 0,01 mol%, temperature 160 °C, and polymerization length 4 hours. PLA with molecular weight Mw= 447 ± 7,8 kg.mol-1 was prepared at these conditions and good repeatability of the result was achieved. The effect of naturally occurring lactide contaminants and their influence on the course and ROP result was experimentally verified on the optimized polymerization system. The purpose was to explore the effect of lactide contamination with water and ethanol as natural lactide contaminants. The results clearly confirm the orderly lower sensitivity of the polymerization system for the presence of ethanol as compared to water contamination. In the case of the presence of water, the course and the result of the polymerization in terms of both the conversion and achieved molecular weights are negatively affected, even when the water content is in the order of 0,001%. Conversely, the presence of ethanol has a positive effect on lactide conversion and polymer polydispersity. Lactides with an alcohol content of about one-tenth of a percent are suitable to reach molecular weights of PLA similar to commercially available products. This difference shoves a significant advantage in the proposed technology of preparing PLA from ethyl lactate, especially for easier purification of crude lactide into polymer grade purity.
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Influence of disinfectants on the content of lactic acid in the production of refined sugar
Novotná, Hedvika ; Skoumalová, Petra (referee) ; Horák, Radek (advisor)
The diploma thesis compares the effectiveness of disinfectants on the content of the lactic acid. The disinfectants used for the experimental part are formalin and BetaStab®. The content of glucose and lactic acid was observed and compared after processing conventional beet and bio-beet. Based on the analysis of the measured data, it was found that the highest disinfecting effect on the lactic acid content had formalin, the avearge lactic acid value was 275 mg/l. In experiment with BetaStab® disinfection the average value of the lactic acid was 350 mg/l. When the beet was processed without the use of disinfection, this average lactic acid was 371 mg/l and in the untreated treatment of the bio-beet, the lactic acid content was 467 mg/l. The glucose content of formalin disinfection diffusion juice reached an average of 573 mg/l. When BetaStab® disinfection was applied, the average glucose content was 348 mg/l and a similar value was measured for the bio-beet treatment (328 mg/l). The highest glucose content had untreated conventional beet, where an average value of 690 mg/l was reached.
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Marketing reasearch cosmeticals for animals
Bartoňová, Klára ; Mgr.Jan Ríha,Ph.D. (referee) ; Souralová Popelková, Miriam (advisor)
This Bachelor's Thesis deals with marketing research of the market with cosmetics for animals. In the practical part of the thesis a survey of the market was carried out. For this purpose a questionnaire was developed and sent out to owners of domestic animals. The questionnaire was then verbally evaluated and the crucial results were put into a graph. The theoretical part focuses on description of the most used veterinary preparations, their specifics, the most important chemicals contained in them, sensory evaluation of products, potential toxicity and undesirable effects on an animal. The valid legislation requirements applying to veterinary preparations within Czech Republic are mentioned in the conclusion. To specify individual products correctly I contacted a number of distributors concerned with the issue.
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The Study of Ethyllactate Synthesis from Lactic Acide Salts
Hlavatá, Daniela ; Figalla, Silvestr (referee) ; Petrůj, Jaroslav (advisor)
This diploma thesis deals with senthesis of lactic acid ethyl ester from slats of lactic acid. The literature review has been processed in the theoretical part of the diploma thesis. It is focused on manufacturing technologies of lactic acid esters, mainly on ethyl lactate by conventional and non-conventional ways of producing. Also the literature review involves producing of lactic acid and slats of lactic acid by fermentation because subsequently is possible produce ethyl lactate from that two substances. The laboratory apparatus for preparation of ethyl lactate and methyl lactate has been designed, realized and verificated function of it in the experimental part. There were carried out laboratory experimnets for production ethyl lactate and methyl lactate in this apparaturs.
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Biotechnological production of selected metabolites on whey substrate
Gadová, Martina ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
The submitted master thesis deals with assessment of the possibility of using of cheese whey for biotechnological production. Study content composition of lyophilized whey, optimization of acid hydrolysis and preparation of cultivating mediums with different content and treatment of cheese whey. Between the aims of this thesis belong also screening of microbial producers, interesting for biotechnology and looks at their growth and production of selected metabolites of cultivation mediums containing cheese whey. All substrates and produced metabolites where examined with UHPLC-PDA-RI and GC-FID: Amount of produced microbial lipids was determined by gravimetric analysis. Examined microorganisms belonged to yeast genus Saccharomyces, Metschnikowia and bacterial genus Lactobacillus and its focused on production of ethanol, microbial lipids and lactic acid. The highest yields with using yeasts were obtained using production medium containing hydrolysed lactose in cheese whey. The highest production, in case of bacteria, was obtained using non-hydrolysed, untreated cheese whey production medium.
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Direct Synthesis of High-Molecular Polymers of Lactic Acid
Mikulík, David ; Kupka, Vojtěch (referee) ; Petrůj, Jaroslav (advisor)
This master thesis deals with the direct synthesis of polymers from lactic acid. The theoretical part focuses on both natural and synthetic ways of production the lactic acid monomer, their advantages and properties. Furthermore, the theoretical part focuses on the synthesis of poly(lactic acid) (PLA) from lactide, and direct polycondensation from lactic acid discussing about influences of catalysts, co-catalysts as well as chain extenders. The experimental part focuses on the synthesis of PLA polymers and co-polymers wherein investigates suitable catalysts, reaction medium for azeotropic dehydration and co-catalyst influence on products. Thermal and analytical analysis of PLA polymers are mentioned at the end of the experimental part.
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