Electrospinning or electrostatic fibre spinning employs electrostatic force to draw fibres from a liquid, either a polymeric solution or a polymer melt in the form of a charged jet. The jet solidifies and is deposited on a collector in the form of a non-woven fibrous mat. Electrospun fibres have diameters between several nanometres to a few microns, which is one of the main advantages of the process, as materials at the nanoscale have shown great potential in a wide range of healthcare and energy applications. The initial selection of solvents to dissolve the polymer for production of electrospun defect-free nanofibres has generally been based on experience from similar polymer-solvent systems. The selection of a solvent is important to control the fibre surface morphology that would eventually determine the field of application for the electrospun nanofibrous structures. However, little attempt has been made to study the correlation between the solubility behaviour of the polymer in different solvents and the electrospinnability of the polymer solutions. From this perspective, the first part of this thesis focused on the selection of different solvents for the production of poly (lactic acid) (PLA) nanofibres. Solution properties were measured and the electrospun nanofibrous structures were analysed in terms of morphology and nanofibre diameter. Understanding the molecular interactions between polymer and solvents enables the correct solvent selection to ensure the desired nanofibrous structure. Solubility is not the only criterion for nanofibre formation from a polymer solution. Polymer concentration is one of the main factors affecting electrospinning. For this reason, a relationship between PLA concentration and nanofibre morphology was determined by solution property measurements. A three step systematic methodology has been proposed in this thesis in order to select appropriate solvent and polymer concentration for the production of homogeneous electrospun mats made of defect-free nanofibres. This methodology was validated for PLA nanofibres, but it can be used for a wide range of polymers. It simplifies the solvent selection process and can significantly improve the trial and error approaches used at present. Despite several models for electrospinning having been proposed to predict the behaviour of the electrospun jet, there are no simple methods for a priori prediction of the final morphology of the electrospun mat from the knowledge of solution properties and electrospinning process parameters. Moreover the prediction of nanofibre diameter is still a difficulty and little research has been done on this. For these reasons, the second part of this thesis is dedicated to understanding the effect of some process parameters on the jet electric current and hence on the morphology of PLA nanofibres. The values of current measured were used to verify an equation proposed in the literature for the prediction of the final diameter. The experimental diameter of the PLA nanofibres was compared with the predicted value. In the last chapter coaxial electrospinning was employed to produce PLA nanofibres with a core shell structure for the incorporation of a model hydrophilic drug in the nanofibre core. The large surface area to volume ratio of nanofibres offers the great advantage of higher efficiency of encapsulation and better control of the release profile compared with other drug delivery systems. Even though successful encapsulation of drug and proteins have been reported, it is not clear how to verify the continuous drug distribution in the core throughout the whole length of the fibre. The solution properties of both core and shell strongly affect the outcome of the electrospinning process. For this reason, several techniques have been used to verify the formation of a core shell structure and proper encapsulation of the drug. In addition, the efficiency of drug encapsulation was evaluated and drug release studies were performed.

Orientadores: Maria do Carmo Alberto-Rincon, Paulo Pinto Joazeiro / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-08T13:27:40Z (GMT). No. of bitstreams: 1 Silva_DeboraReginaMachado_D.pdf: 11484449 bytes, checksum: bfe84eec483f10c38fb1eb8fdfd9da3d (MD5) Previous issue date: 2007 / Resumo: A utilização de biomateriais para a reparação de tecidos tem exigido o entendimento de seu comportamento in vivo. Com o intuito de avaliar a interação célula-polímero in vivo e in vitro, membranas de PLLA contendo 7% de plastificante tri-etil-citrato foram obtidas para análise pelo método de evaporação de solvente. Discos desse material foram implantados no tecido subcutâneo dorsal de ratos e retirados após um período de 2 a 180 dias de implante, processados para embebição em: a) parafina, para detecção de fibras reticulares; imunocitoquímica, utilizando-se anticorpos anti-vimentina, a-actina de músculo liso e anti-colágeno III; e análise morfométrica da incidência temporal de células gigantes; e b) resina k4M, para detecção ultraestrutural de filamentos de vimentina. Quanto à análise in vitro, fibrocondrócitos de menisco de coelhos foram extraídos e cultivados em membranas de PLLA e em lamínulas para avaliar a viabilidade da aplicação dessas membranas como substrato para crescimento celular. A análise in vitro foi realizada após 3, 8, 12, 15 e 18 dias de cultivo através de microscopia de luz e eletrônica de varredura. Os resultados da análise in vivo mostraram a deposição de fibras reticulares no interior da membrana, presença de grande número de fibroblastos e células endoteliais marcadas com anti-vimentina, além de células gigantes com expressão diferencial de vimentina e miofibroblastos na cápsula. Os resultados estatísticos da análise morfométrica da incidência temporal dessas células mostrou aumento gradual do número de células gigantes, bem como de núcleos ao longo do tempo, atingindo um platô nos períodos mais tardios após a implantação. A análise in vitro mostrou que os fibrocondrócitos aderem, diferenciam-se principalmente em células condrocíticas, e produzem grande quantidade de elementos fibrilares da matriz extracelular para formar um tecido fibroso altamente organizado que ocupa principalmente as bordas laterais e lisas da membrana. Na cultura de fibrocondrócitos em lamínulas, notou-se que as células adquirem uma morfologia predominantemente do tipo fibroblástica, com deposição de elementos fibrilares. Membranas de PLLA mostraram sustentar por um período maior a viabilidade de fibrocondrócitos in vitro, estimulando a formação de um tecido fibroso organizado, quando comparado a sistemas de cultivo em lamínulas / Abstract: The use of biomaterials for tissue repair has been demanding the understanding of his in vivo behavior. To evaluate the in vivo and in vitro polymer-cell interaction, PLLA membranes containing 7% of plasticizer were obtained by casting. Discs of this material were introduced in the subcutaneous dorsal tissue of mice and withdrawn after a period from 2 to 180 days of implant, processed by embedding in: a) paraffin, for detection of reticular fibers; immunocytochemistry, by using antibodies against vimentin, smooth muscle¿s a-actin, and type III collagen; and morphometric analysis of the temporary incidence of giant cells; and b) resin k4M for ultrastructural detection of vimentin filaments. For the in vitro analysis, fibrochondrocytes of rabbit¿s meniscus were extracted, and cultivated in membranes of PLLA and in glass coverslips to value the viability of the application of these membranes as substrate to cellular growth. The in vitro analysis was carried out after 3, 8, 12, 15 and 18 days of cultivation through light and electron microscopy. The results of the in vivo analysis showed the deposition of reticular fibers inside the membrane, presence of great number of fibroblasts and endothelial cells marked with anti-vimentin, besides giant cells with differential expression of vimentin, and myofibroblasts in the capsule. The statistical results of the morphometric analysis of the temporary incidence of these cells showed gradual increase of the giant cells number, as well as of nucleus number in these cells along the time, reaching a plateau in the late periods after the implantation. The in vitro analysis showed that the fibrochondrocytes adhere to the membrane, and that they differentiates mainly in chondrocytic cells, and produce large amount of extracellular matrix fibers to form a highly organized fibrous tissue that occupies principally the side and smooth edges of the membrane. In the fibrochondrocytes culture in glass coverslips, it was noticed that the cells acquire a predominantly fibroblastic-like morphology, with deposition of matrix fibers. Membranes of PLLA sustained the in vitro fibrochondrocytes viability for a bigger period of time, stimulating the formation of a fibrous organized tissue when compared to glass coverslips cultivation systems / Doutorado / Histologia / Doutor em Biologia Celular e Estrutural

Orientador: Rubens Maciel Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-26T08:53:26Z (GMT). No. of bitstreams: 1 Lopes_MilenaSavioli_D.pdf: 3945173 bytes, checksum: acae59a0572d443eb01b61664f7b95cd (MD5) Previous issue date: 2014 / Resumo: Atualmente, o conceito de sustentabilidade vem ganhando cada vez mais espaço e com ele os desafios de melhorar os processos industriais. O uso dos microrreatores surge como uma opção atraente e com potencial para atender às diversas e crescentes exigências ambientais e econômicas. Por outro lado, o mau funcionamento ou a perda de funções totais ou parciais de um órgão ou tecido resultante de doenças ou traumas, é um dos mais importantes e preocupantes problemas de saúde pública, atingindo um número significativo de pessoas em todo o mundo. Dessa forma, o principal objetivo dessa tese foi o desenvolvimento, fabricação e avaliação de microrreator capaz de realizar a síntese de polimerização do poli (L-ácido láctico) (PLLA) utilizado como implantes biomédicos. Para o cumprimento desse objetivo, foi necessário avaliar separadamente as condições de síntese e as rotas de obtenção do PLLA. O rota escolhida de polimerização para ser desenvolvida em microrreator foi a policondensação direta. Os produtos foram gerados e caracterizados por diferentes técnicas de análise. Os resultados mostraram semelhança entre os dois produtos e sua avaliação citotóxica permitiu confirmar sua aplicação com biomaterial. Pode-se concluir que o microrreator proposto apresentou-se com grande potencial na realização da polimerização do PLLA por policondensação direta do ácido láctico / Abstract: Currently, the concept of sustainability has been gaining more space and with it the challenges of improving industrial processes. The use of microreactors emerges as an attractive and potential option to meet the diverse and growing environmental and economic requirements. Furthermore, the malfunction or loss of total or partial functions of an organ or tissue resulting from disease or trauma is a major concern and public health problems, achieving a significant number of people worldwide. Thus, the main objective of this thesis was the development, manufacture and evaluation of microreactor capable of performing the synthesis of polymerization of poly (L-lactic acid) (PLLA) used as biomedical implants. To fulfill this objective, it was necessary to separately evaluate the conditions of synthesis and routes of obtaining the PLLA. The route chosen for polymerization with microreactor to be developed was in direct polycondensation. The products were generated and characterized by different analysis techniques. The results showed similarity between the two products and their cytotoxic evaluation confirmed their application with biomaterial. It can be concluded that the idea of microreactor proposed has been presented with great potential in fulfilment of the polymerization of the PLLA by direct polycondensation of lactic acid / Doutorado / Desenvolvimento de Processos Químicos / Doutora em Engenharia Quimica

Orientador: Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T03:40:37Z (GMT). No. of bitstreams: 1 Siqueira_JulianadeFaria_M.pdf: 1753771 bytes, checksum: 3b8feb2d517bd09db69f780a2292e100 (MD5) Previous issue date: 2011 / Resumo: Os avanços na medicina moderna, odontologia e engenharia aliados ao aumento da expectativa de vida, permitiram o desenvolvimento de técnicas de biomanufatura e biomateriais que geram uma melhor qualidade de vida. Essas técnicas devem permitir a imitação de estruturas vivas, tanto em forma como em função, tornando possível substituir tecidos defeituosos ou faltantes. Nesse contexto, o estudo e aplicação de poliésteres bioreabsorvíveis como suporte de crescimento celular (ou scaffolds) na engenharia tecidual tem se mostrado uma área muito promissora de pesquisa. Dentre os poliésteres bioreabsorvíveis comumente utilizados, o poli(ácido láctico) (PLA) ocupa posição de destaque devido a sua excelente biocompatibilidade e propriedades mecânicas. O PLA é um termoplástico de alta resistência e é degradado no corpo por simples hidrólise do éster em uma taxa que pode ser controlada. A forma mais comum de se obter PLA de alta massa molecular é via polimerização por abertura de anel do dímero cíclico do ácido láctico, também conhecido como lactide, e o catalisador mais utilizado atualmente é o octoato de estanho ou Sn(Oct)2. Porém, a fim de possibilitar a síntese de um material isento de metais, a utilização de enzimas como catalisadores tem despertado o interesse de estudiosos. Além de serem consideradas atóxicas, as enzimas viabilizam a polimerização sob condições brandas em relação à pressão, temperatura e pH. O objetivo desse trabalho foi fazer um estudo prospectivo sobre as técnicas existentes para a síntese do PLA e sintetizálo a partir de uma rota química, utilizando Sn(Oct)2 como catalisador, e outra enzimática utilizando o biocatalisador Lipase B para futuramente obter biodispositivos para utilização na engenharia tecidual. A massa molecular do polímero foi obtida por GPC e sua estrutura química foi confirmada por FTIR. As propriedades térmicas foram estudadas por DSC e TGA. O PLA obtido a partir da rota química atingiu massa molecular equivalente a 8353 g/mol após 7h de reação a 160°C com 0,1% de Sn(Oct)2. Para a rota enzimática, foi constatado que a policondensação foi mais eficaz em relação à técnica de abertura de anel do lactide e um polímero com massa molecular igual a 1719 g/mol foi obtido depois de 77h de reação a 70°C com 0,5% de Lipase B. Em um comparativo de custos de fabricação, a rota química se mostrou mais atrativa em um primeiro momento, porém foi comprovado que com a reutilização da Lipase B, a polimerização enzimática pode ser viabilizada economicamente / Abstract: The advances in modern medicine, dentistry and engineering, combined with the increase of life expectancy, have allowed the development of techniques for biomanufacturing and biomaterials that create a better life quality. These techniques should enable the mimicking of living structures, both in form and function, making it possible to replace defective or missing tissues. In this context the study and application of bioresorbable polyesters as scaffolds in tissue engineering has shown a very promising area of research. Poly(lactic acid), PLA, stands out among the commonly used bioresorbable polyesters due to its excellent biocompatibility and mechanical properties. PLA is a thermoplastic, high strength and is degraded in the body by simple hydrolysis of the ester at a rate that can be controlled. The most common way to obtain high molecular mass PLA is by ring-opening polymerization of the lactic acid cyclic dymer, lactide, and currently the widely used catalyst for biomedical purposes is Stannous Octoate or Sn(Oct)2. However, in order to enable the synthesis of a metal-free material, the use of enzymes as catalysts has attracted the interest of researchers. In addition to being considered non-toxic, the enzyme enables the polymerization under mild conditions with regard to pressure, temperature and pH. The aim of this work was to make a prospective study on the existing techniques for the synthesis of PLA and synthesize it from a chemical route, using Sn(Oct)2 as catalyst, and from a enzymatic route using the biocatalyst Lipase B for future development of biodevices to be used in tissue engineering. The polymer molecular mass was obtained by GPC and its chemical structure was confirmed by FTIR. Thermal properties were studied by DSC and TGA. PLA obtained from the chemical route reached molecular mass equivalent to 8353g.mol-1 after 7 hours of reaction at 160°C with 0,1% Sn(Oct)2. For the enzymatic route, it was found that the polycondensation was more effective compared to the technique of ring opening of lactide and polymer with a molecular mass of 1719g.mol-1 was obtained after 77 hours reaction time at 70°C with 0,5% of Lipase B. Comparing manufacturing costs, chemical route were more attractive at first, but it was proven that with Lipase reuse enzymatic polymerization can be economically viable / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

La thèse porte sur l’étude de la morphologie et des différentes propriétés thermiques, mécaniques et barrières à la vapeur d’eau des nanobiocomposites à base de poly acide lactique (pla). La première partie est consacrée au greffage de l’anhydride maléique (am) sur le poly acide lactique plagma et à la mise en oeuvre de nanobiocomposites pla/cloisites, plagma/cloisites et pla/plagma/cloisites en utilisant deux cloisites® différentes (c20a et c30b), préparés par voie fondue. Au travers des différentes techniques utilisées, les résultats révèlent que les nanobiocomposites pla/cloisites élaborés se caractérisent par une morphologie mixte intercalée-exfoliée. L’ensemble des échantillons élaborés indiquent une meilleure dispersion de la cloisite apolaire c20a en présence de l’anhydride maléique et la réagrégation de la cloisite polaire c30b et par conséquent, l’amélioration à la fois des propriétés mécaniques et barrières à la vapeur d’eau des nanobiocomposites à base de la c20a. La seconde partie traite l’influence des groupements fonctionnels d’oxyde de graphène synthetisé au laboratoire et de graphène fonctionnalisé époxy commercialisé et fournit par nanovia (france) sur la dispersion des nanofeuillets de graphène au sein de la matrice pla, en présence ou en absence du compatibilisant plagma. L’étude révèle que la présence du compatibilisant améliore la dispersion de deux nanocharges étudiées. Le maximum des performances rhéologiques indiquant la meilleure dispersion de la nanocharge est enregistré pour une faible quantité d’oxyde de graphène possédant plus de groupements fonctionnels contenant l’atome d’oxygène. Les propriétés thermiques et barrières ont été considérablement améliorées avec l’incorporation des deux nanocharges et en présence de l’agent compatibilisant plagma. L’étude montre aussi que les propriétés mécaniques en traction des nanobiocomposites à base de graphène fonctionnalisé époxy (gfe) ont été améliorées en présence du plagma. / The thesis focuses on the study of the morphology and thermal, mechanical and barrier properties of the nanobiocomposites based on poly lactic acid (pla). The first part is devoted to the grafting of maleic anhydride (ma) on the poly lactic acid plagma and the elaboration of the nanobiocomposites pla/cloisites, plagma/cloisites and pla/plagma/cloisitres using two different cloisites (c20a and c30b), prepared by melt intercalation and the characterization of the main properties. The results indicate that the pla/cloisites nanobiocomposites exhibit a mixed intercalated-exfoliated morphology. All the prepared samples showed an improvement in both thermal, mechanical and barrier properties in the presence of the nanofiller. All prepared samples show better dispersion of apolar cloisite (c20a) in the presence of maleic anhydride and reaggregation of the polar cloisite (c30b) and therefore, the improvement of both the mechanical and barrier properties of the nanobiocomposites based on c20a. The second section discusses the effect of the functional groups of graphene oxide synthetized in the laboratory and the graphene fonctionnalized epoxy marketed and supplied by nanovia (france) on the dispersion of the graphene nanofillers in the pla matrix. The study reveals that the presence of compatibilizer improves the dispersion of two studied nanofillers. Maximum rheological performance indicating better dispersion of the nanofiller is registered for a small amount of graphene oxide (og) with more functional groups containing oxygen atom. The thermal and barriers properties have been considerably improved with the incorporation of two nanofillers and in the presence of plagma compatibilizer. The study also shows that the tensile properties of the pla containing graphene functionalized epoxy (gfe) were improved in the presence of plagma.

The synthesis and characterization of a series of chiral indium complexes bearing a tridentate NNO ligand are reported. The ligand 2-[[[(dimethylamino)cyclohexyl]amino]methyl]- 4,6-bis(tert-butyl) phenol (H₂NNO) was synthesized via a previously published procedure and bound to indium by both a protonolysis and salt metathesis route. A dimethylated indium complex (NNO)InMe₂ (1) was isolated by reaction of InMe₃ with H₂NNO. A one-pot saltmetathesis route was used to produce a unique mixed-bridge dinuclear indium complex [(NNO)InCl] ₂(μ-OEt)(μ-Cl) (3) from a mixture of indium trichloride, potassium ethoxide and the monopotassiated salt of the ligand, KH(NNO). Direct reaction of KH(NNO) and indium trichloride resulted in the formation of (NNO)InCl₂ (4) which was carried forward to 3 by reaction with sodium ethoxide. The complex 3 is active for the ROP of β-butyrolactone ε-caprolactone and lactide and is the first reported indium-based catalyst for lactide or β-butyrolactone ROP. Kinetic studies of 3 for ROP of LA revealed that catalyst was well-behaved, and that the rate was first order with regard to lactide and catalyst. The enthalpy and entropy of activation for the ROP were experimentally determined. Polymer produced by ROP by 3 has narrow molecular weight distribution and a good correlation is seen between the observed moleular weight and monomer loading. A mechanism was proposed for 3 acting as a catalyst for the ROP of lactide; however further experiments are required to confirm this mechanism. Polymer samples isolated from the ROP of rac-lactide by rac-3 show isotactic enrichment. It is postulated that the chiral catalyst 3 is exerting stereocontrol via an enantiomorphic site control mechanism. / Science, Faculty of / Chemistry, Department of / Graduate

Orientadores: Ana Rita Morales. Maria Aparecida Marin-Morales / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-27T19:07:36Z (GMT). No. of bitstreams: 1 Palsikowski_PaulaAlessandra_M.pdf: 11105258 bytes, checksum: 8fba42f89a892e4e1fd4741c459f3b74 (MD5) Previous issue date: 2015 / Resumo: Os polímeros biodegradáveis, como o PLA e o PBAT, são considerados uma opção viável para minimizar os efeitos do grande descarte de resíduos sólidos. Este trabalho apresenta o estudo da biodegradação em solo do poli (adipato-co tereftalato de butileno) (PBAT) e poli (ácido lático) (PLA) e de suas blendas compatibilizadas por um extensor de cadeia. As amostras foram caracterizadas mediante Difração de Raios-X (DRX), análise termogravimétrica (TGA), Calorimetria Diferencial Exploratória e Espectroscopia de Infravermelho (FTIR). Para avaliar a degradação, as amostras foram enterradas em solo em condições controladas em laboratório. As amostras degradadas foram regularmente retiradas de solo e analisadas por inspeção visual e pela alteração na massa molar por Cromatografia de Permeação em Gel (GPC). A biodegradabilidade destes materiais também foi avaliada pela quantificação da taxa de mineralização. Visualmente foram observadas mudanças na coloração, trincas e fragmentação. Após 360 dias de degradação foram observados apenas pequenos fragmentos de PBAT com manchas pretas, as blendas 25/75 e 75/25 estavam fragmentadas, enquanto que o PLA apresentou apenas trincas. A massa molar ponderal média do PLA foi a que mais diminuiu em 360 dias de degradação. Os resultados evidenciaram uma forte influência da presença do extensor de cadeia na massa molar do PBAT e das blendas. O PBAT apresentou a maior taxa de mineralização, seguido pela blenda 25/75, enquanto que a blenda 75/25 e o PLA apresentaram uma taxa de mineralização menor. As curvas do DSC e DRX revelaram um aumento na cristalinidade durante o processo de degradação. O FTIR mostrou pequenas variações nas bandas antes e depois da degradação. O estudo da ecotoxicidade dos resíduos resultantes da degradação dos polímeros no solo permitiu avaliar os efeitos citotóxicos, genotóxicos e mutagênicos por meio de bioensaios com o organismo teste Allium cepa germinado nos solos onde ocorreu a degradação dos materiais. Com base nos resultados obtidos, os materiais estudados não se mostraram fitotóxicos, genotóxicos e tampouco mutagênicos para as células meristemáticas. As blendas compatibilizadas do PLA com o PBAT não apresentaram vantagens no processo de biodegradação em relação ao polímeros originais / Abstract: Biodegradable polymers, as PLA and PBAT, are considered a feasible option to minimize the effects of high disposal of solid waste. This work presents the study of biodegradation in soil of poly (adipate co-terephthalate of butylene) (PBAT) and poly (lactic acid) (PLA) and their blends compatibilized with a chain extender. The samples were characterized by X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). To evaluate the degradation, the samples were buried in soil in controlled laboratory conditions. Degraded samples were regularly taken from soil and analyzed by visual inspection and by the changes in molecular weight by Gel Permeation Chromatography (GPC). The biodegradability of these materials was assessed by quantifying the rate of mineralization. Visually it was observed changes in color, cracks and fragmentation. After 360 days of degradation it was observed only small fragments of PBAT stained in black, and the 25/75 and 75/25 blends were broken, while the PLA showed only cracks. The ponderal average molecular weight of PLA was the must decreased in 360 days of degradation. The results showed a strong influence of the chain extender presence in changing the molecular weight of PBAT and the blends. The PBAT shows the higher mineralization rate, followed by the 25/75 blend, while the 75/25 blend and the PLA had a lower mineralization rate. The DSC and DRX curves revealed an increase of crystallinity during the degradation process. The FTIR showed slight changes at bands before and after degradation. The study of ecotoxicity of residues resulting from polymers degradation in soil allowed evaluate the citotoxy, genotoxy and mutagenic effects by the bioassays using the test organism Allium cepa germinated in soils where degradation of the materials took place. Based on the obtained results, the studied materials were not fitotoxic, genotoxic nor mutagenic for meristematic cells. The compatibilized blends of PLA with PBAT showed no advantage in the biodegradation process in relation to the original polymers / Mestrado / Mestra em Engenharia Química

Diploma thesis deals with preparation of polymer blend of polymer A and polymer B. Knowledge of polymer blends forming, thermodynamics and function of compatibilizer is contained in the theoretical part. Polymer blend A/B of weight ratios 75/25, 50/50 and 25/75 wt% were prepared by physical compatibilization. Concentration of compatibilizer was 5 wt%, in the case of A/B 50/50 wt% concentration of compatibilizer was 10 and 30 wt%, respectively. Blending was achieved with twin-screw extruder at 230 °C and 100 rpm. Second method used for A/B blending was based on reactive compatibilization which was achieved with Brabender kneader at 230 °C, 50 rpm and reaction time 10 minutes. Concentration ratios of A/B were 75/25, 50/50 and 25/75 wt%. Itaconic acid anhydride and maleic anhydride 0.5 and 5 wt% were used as monomer. 2,5-dimethyl-2,5-bis(tert-buthylperoxy)hexan was (Luperox 101) used as an initiator. Difference between compatibilized and noncompatibilized blends was characterized by scanning electron microscopy, tensile test, differential scanning calorimetry, melt flow index measuring, acid-base titration and FT-IR spectroscopy.

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.

No description available.