Submitted by PPG Engenharia e Tecnologia de Materiais (engenharia.pg.materiais@pucrs.br) on 2018-06-25T13:24:34Z No. of bitstreams: 1 Dissserta??o final_Lucas Weber Dias.pdf: 2263503 bytes, checksum: ea9c29b6b538c56ea795610f7bc5a808 (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-06-29T13:30:33Z (GMT) No. of bitstreams: 1 Dissserta??o final_Lucas Weber Dias.pdf: 2263503 bytes, checksum: ea9c29b6b538c56ea795610f7bc5a808 (MD5) / Made available in DSpace on 2018-06-29T13:38:08Z (GMT). No. of bitstreams: 1 Dissserta??o final_Lucas Weber Dias.pdf: 2263503 bytes, checksum: ea9c29b6b538c56ea795610f7bc5a808 (MD5) Previous issue date: 2017-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The main function of the packaging is to protect the cosmetic from the external environment, avoiding undesirable changes in the product that is contained inside, and thus indispensable for its storage and transpotation. However, its disposal improperly generates a large volume of solid waste, which is directly related to the environmental impact. One of the alternatives to minimize this impact is the use of packages made from biodegradable polymeric films based on polyacrylic acid (PLA), poly (lactic acid ? co- glycolic acid) (PLGA) and polycaprolactone (PCL), blends of theses polymers and incorporation of Zeolites 13x. The thermal, mechanical optical, water vapor barrier and degradation time in saline solution of polymeric systems are evaluated for application as cosmetic packaging. The technique used for the preparation of the polymer films was that of Solvent Casting. The polymer films were characterized by the techniques of UV-Vis Spectrophotometry, Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scsannig Electron Microscopy (SEM), transparency, water vapor permeability, mechanical assay and absorption spectroscopy atomic. The transmittance results showed that the PCL and PLA blends showed greater blockage to the passage of radiation (190 - 1100nm) and water vapor permeability. The incorporation of PLA or PLGA to the pure PCL resulted in material with batter thermal properties, but more rigid and brittle, not modifying the degradation process until 120 days of incubation. The incorporation of 15% Zeolite 13x into the PCL/PLA blends did not significantly modify the properties evaluated. / As embalagens t?m como principal fun??o, proteger o cosm?tico do meio externo, evitando que ocorram altera??es indesej?veis no produto que est? contido no seu interior, sendo assim indispens?vel para o seu armazenamento e transporte. Por?m, o seu descarte de forma inadequada gera um grande volume de res?duos s?lidos, que est? diretamente relacionado com o impacto ambiental. Uma das alternativas para minimizar este impacto ? a utiliza??o de embalagens confeccionadas a partir de pol?meros biodegrad?veis. Desta maneira, o presente trabalho tem como objetivo a prepara??o e caracteriza??o de filmes polim?ricos biodegrad?veis baseados em Poli ? ?cido l?ctico (PLA), Poli (?cido l?ctico ? co- ?cido glic?lico) (PLGA) e Policaprolactona (PCL), blendas destes pol?meros e incorpora??o de Ze?litas 13x. S?o avaliadas as propriedades t?rmicas, mec?nicas, ?pticas, de barreira a vapor de ?gua e o tempo de degrada??o em solu??o salina dos sistemas polim?ricos, visando aplica??o como embalagem para cosm?ticos. A t?cnica utilizada para a prepara??o dos filmes polim?ricos foi a de Solvent Casting. Os filmes polim?ricos foram caracterizados pelas t?cnicas de Espectrofotometria UV-Vis, Calorimetria Explorat?ria Diferencial (DSC), An?lise Termogravim?trica (TGA), Microscopia Eletr?nica de Varredura (MEV-FEG), transpar?ncia, permeabilidade a vapor de ?gua, ensaio mec?nico e Espectroscopia de absor??o at?mica. Os resultados de transmit?ncia mostraram que a blenda de PCL e PLA apresentou maior bloqueio ? passagem de radia??o (190 nm ? 1100 nm) e ? permeabilidade de vapor de ?gua. A incorpora??o de PLA ou PLGA ao PCL puro resultou num material com melhores propriedades t?rmicas, por?m mais r?gido e quebradi?o, n?o modificando o processo de degrada??o at? 120 dias de incuba??o. A incorpora??o de 15% Ze?lita 13x ? blenda de PCL/PLA n?o modificou significativamente as propriedades avaliadas.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2018-04-11T19:34:25Z No. of bitstreams: 1 LucasRicardoFernandesFigueiredo_TESE.pdf: 6637394 bytes, checksum: 61ae8caa80c576775c523ad68f0527cc (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2018-04-12T22:55:55Z (GMT) No. of bitstreams: 1 LucasRicardoFernandesFigueiredo_TESE.pdf: 6637394 bytes, checksum: 61ae8caa80c576775c523ad68f0527cc (MD5) / Made available in DSpace on 2018-04-12T22:55:55Z (GMT). No. of bitstreams: 1 LucasRicardoFernandesFigueiredo_TESE.pdf: 6637394 bytes, checksum: 61ae8caa80c576775c523ad68f0527cc (MD5) Previous issue date: 2017-12-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / ?Adesivos verdes? t?m despertado grande interesse cient?fico e tecnol?gico como alternativa aos produtos comerciais convencionais, que em geral, liberam subst?ncias t?xicas e levam um longo per?odo de tempo para degradar. Entretanto, as propriedades mec?nicas limitadas e a r?pida degrada??o de alguns pol?meros biodegrad?veis limitam seu uso na maioria das aplica??es pr?ticas. No presente trabalho, comp?sitos foram preparados usando pol?meros biodegrad?veis e nanowhiskers de celulose (NWC) visando sua utiliza??o como adesivos para madeira. O objetivo da pesquisa foi estudar o efeito da adi??o dos nanowhiskers de celulose (NWC) nas propriedades mec?nicas e na degrada??o dos pol?meros. Os pol?meros biodegrad?veis sintetizados por policondensa??o ? base de glicerol e ?cidos foram poli (adipato de glicerol) - PGA, poli (maleato de glicerol) - PGM, poli (citrato de glicerol) - PGC, poli (ftalato de glicerol) - PGPh, poli (succinato de glicerol) PGSu e poli (sebacato de glicerol) - PGS. Al?m desses, copol?meros poli (glicerol succinato-co-maleato) - PGMSu, poli (glicerol succinato-co-adipato) - PGASu e poli (glicerol adipato-co-maleato) - PGMA foram tamb?m sintetizados. Nanowhiskers de celulose (NWC) foram adicionados aos pol?meros para avalia??o dos seus efeitos na melhoria das propriedades mec?nicas e no controle da taxa de degrada??o. Os materiais foram produzidos com a adi??o de 0, 5, 10 e 20% em peso de NWC. Os pol?meros puros e os comp?sitos foram analisados por Calorimetria Diferencial de Varredura (DSC), An?lise termogravim?trica (TGA), difra??o de Raios X (DRX) e espectroscopia Infravermelho por transformada de Fourier (FTIR). Juntas adesivas foram produzidas em corpos de prova de pinus (Pinus elliottii) e angelim (Vatairea heteroptera Ducke) e submetidas a degrada??o por envelhecimento acelerado e testes de cisalhamento sob tra??o. Juntas coladas produzidas com adesivos ? base de acetato de polivinila - PVAc e cianoacrilato foram tamb?m testadas, nas mesmas condi??es, para fins de compara??o. As an?lises t?rmicas indicaram que a maioria dos pol?meros biodegrad?veis ? base de glicerol testados s?o est?veis at? aproximadamente 260?C e a adi??o de NWC aumentou a estabilidade t?rmica (Tonset) de alguns pol?meros em 26?C at? 48?C, enquanto outros n?o foram afetados. As an?lises de superf?cie de fratura por microscopia eletr?nica de varredura (MEV) ap?s os testes de cisalhamento sugerem redu??o de ductilidade com a incorpora??o de NWC ao adesivo. As medidas de ades?o indicaram que os adesivos verdes desenvolvidos a partir de pol?meros de glicerol com 10 e 20% em peso de NWC apresentaram resist?ncia ao cisalhamento superior ao adesivo comercial ? base de PVAc. Os melhores resultados e resist?ncia ao cisalhamento foram obtidos para PGASu com 20% em peso de NWC (2,57 ? 0,36 MPa) e PGM com 20% em peso de NWC (2,33 ? 0,43 MPa), enquanto que a resist?ncia ao cisalhamento do acetato de polivinila - PVAc foi de 1,58 ? 0,18 MPa. O envelhecimento resultou em maior resist?ncia ao cisalhamento de alguns adesivos. A melhoria mais significativa foi obtida para PGMA com 20% em peso de NWC, que atingiu (3,89 ? 0,74 MPa) ap?s 250 h de envelhecimento, portanto, maior que a resist?ncia ao cisalhamento do cianoacrilato (3,12 ? 0,53 MPa). Em ?ltima an?lise, os resultados apresentados neste trabalho sugerem que a adi??o de nanowhiskers de celulose (NWC) ? uma abordagem vi?vel para ajustar as propriedades mec?nicas e degrada??o dos pol?meros biodegrad?veis. / ?Green adhesives? are of great scientific and technological interest as an alternative to conventional commercial products, which often release toxic substances and take long time to degrade. However, the poor mechanical properties and fast degradation of some biodegradable polymers limit their use in most practical applications. In the present work, novel biodegradable composites were prepared using biodegradable polymers and cellulose nanowhiskers (CNW) for their use as wood adhesives. The goal of the investigation was to study the effect of the addition of CNW on the mechanical properties and degradation of the polymers. The biodegradable polymers synthesized by polycondensation based on glycerol and acids were poly(glycerol adipate) - PGA, poly(glycerol maleate) - PGM, poly(glycerol citrate) - PGC, poly(glycerol phthalate) - PGPh, poly(glycerol succinate) - PGSu and poly(glycerol sebacate) - PGS. In addition, the copolymers synthesized were poly(glycerol succinate-co-maleate) - PGMSu, poly(glycerol succinate-co-adipate) ? PGASu and poly(glycerol adipate-co-maleate) ? PGMA. Cellulose nanowhiskers (CNW) were added to the polymers as an approach for improving the mechanical properties and controlling the degradation rate. Composites were produced with the addition of 0, 5, 10 and 20 wt.% of CNW. The neat polymers and composites were analyzed by Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). Adhesively bonded joints were produced in test specimens of slash pine (Pinus elliottii) and angelim (Vatairea heteroptera Ducke) and subjected to accelerated aging and tested under shear by tensile loading. Bonded joints produced with polyvinyl acetate - PVAc and cyanoacrylate based adhesives were also tested under the same conditions for comparison purposes. Thermal analyses indicated that most of the biodegradable glycerol-based polymers tested are stable up to about 260?C and the addition of CNW increased the thermal stability (Tonset) of some polymers by 26?C up to 48?C, while others were not affected. Analyses of the fracture surfaces after the shear tests by Scanning Electron Microscopy (SEM) suggest less ductile fracture with the incorporation of CNW to the adhesive. The shear strengths of the green adhesives developed from glycerol with 10 and 20 wt.% CNW were greater than that of the commercial PVAc based adhesive. The best results of shear strengths were obtained for PGASu 20 wt.% CNW (2.57 ? 0.36 MPa) and PGM 20 wt.% CNW (2.33? 0.43 MPa), while the shear strength for polyvinyl acetate - PVAc was 1.58 ? 0.18 MPa. Aging improved the shear strength of some adhesives. The best result was obtained for PGMA 20 wt.% CNW, which reached (3.89 ? 0.74 MPa) after 250h of aging, thus greater than the shear strength of cyanoacrylate (3.12 ? 0.53 MPa). Ultimately, the results presented in this work suggest that the addition of cellulose nanowhiskers (CNW) is a viable approach to tailor mechanical properties and degradation of biodegradable polymers.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-07-11T18:42:28Z No. of bitstreams: 1 2016 - K?nia Let?cia Ferreira Pessanha.pdf: 2366902 bytes, checksum: 926a4615f4a193d9328fe681ce73019f (MD5) / Made available in DSpace on 2017-07-11T18:42:28Z (GMT). No. of bitstreams: 1 2016 - K?nia Let?cia Ferreira Pessanha.pdf: 2366902 bytes, checksum: 926a4615f4a193d9328fe681ce73019f (MD5) Previous issue date: 2016-03-02 / CNPq / The use of synthetic materials derived from non-renewable sources has generated a high environmental impact, which required from the industry, the development of polymeric materials based on biodegradable polymers. Polysaccharides such as starch, are capable of forming low cost homogeneous edible films, resulting in aggregate value to the food due to the film increased biodegradability and increased shelf life of packaged food by the possibility of adding antioxidants, nutrients and natural pigments, which raise the nutritional and organoleptic characteristics of the product. This work was aimed at developing and evaluating, chemically and physically, films from filmogenic solutions (SF) developed with cassava starch, freez-dried acai and glycerol, through spreading technique casting. After preparation under controlled conditions, SF were dried at 30 ? 5 ? C for 24 hours in an oven with forced air circulation. The resulting films were unmolded and stowed in relative humidity controlled at 52.9% for six days for further characterization. The developed films were characterized as the quantification of anthocyanins by High-Performance Liquid Chromatography (HPLC), Antioxidant Capacity by ABTS? + and ORAC, thickness, water solubility, permeability to water vapor (PVA), water activity (Aw) , contact angle, optical properties and mechanical properties. At the same time a control film was elaborated (without the addition of acai) that underwent the same physical tests. The results indicated that the addition of acai pulp enabled the development of an edible plastic rich in anthocyanins and higher antioxidant capacity (150,70 ?mol Trolox) than fruist like strawberry and raspberry. The anthocyanins had a higher interaction with the starch molecules, probably through the hydroxyl of both which established hydrogen bonds allowing immobilization of anthocyanins in the film, which was advantageous given the high instability of anthocyanins. The polymeric matrix added with freeze-dried acai had its thickness increased which caused an increase of the PVA, reduction of water solubility and water activity, the latter two being advantageous parameters for a food package. Regarding the mechanical properties, it was observed that the rupture power in drilling and deformation were reduced. In the pull test there was a reduction of stress at break and modulus of elasticity. The deformation in traction showed higher results, indicating that the addition of the freeze-dried acai increased film flexibility. As for color, the film presented a darker color compatible with the fruit, with a potential use for packaging of dark foods. / O uso de materiais sint?ticos oriundos de fontes n?o renov?veis tem gerado um alto impacto a n?vel ambiental, o que demanda da ind?stria o desenvolvimento de materiais a base de pol?meros biodegrad?veis. Polissacar?deos como o amido, t?m a capacidade de formar filmes comest?veis, homog?neos e de baixo custo, gerando valor agregado aos alimentos devido ? maior biodegradabilidade dos filmes e aumento da validade comercial do alimento embalado pela possibilidade da adi??o de compostos antioxidantes, nutrientes e pigmentos naturais ao filme, o que pode elevar as caracter?sticas nutricionais e organol?pticas do alimento. Este trabalho teve como objetivo desenvolver e avaliar, qu?mica e fisicamente, filmes a partir de solu??es filmog?nicas (SF) elaboradas com amido de mandioca, a?a? liofilizado e glicerol, atrav?s da t?cnica de espalhamento casting. Ap?s o preparo sob condi??es controladas, as SF foram desidratadas a 30?C ? 5 ?C por 24h em estufa com circula??o de ar for?ada. Os filmes resultantes foram desenformados e acondicionados em umidade relativa do ar controlada a 52,9% por seis dias para posterior caracteriza??o. Os filmes foram caracterizados quanto a quantifica??o de antocianinas por Cromatografia L?quida de Alta Efici?ncia (CLAE), capacidade antioxidante por ABTS?+ e ORAC, espessura, solubilidade em ?gua, permeabilidade ao vapor de ?gua (PVA), atividade de ?gua (Aw), ?ngulo de contato, propriedades ?pticas e propriedades mec?nicas. Concomitantemente foi elaborado um filme controle (sem adi??o de a?a?) que foi submetido aos mesmos testes f?sicos. Os resultados indicaram que a adi??o do a?a? liofilizado permitiu o desenvolvimento de um filme pl?stico rico em antocianinas e com alta capacidade antioxidante (150,70 ?mol Trolox) superior a frutas como o morango e framboesa. As antocianinas tiveram uma alta intera??o com as mol?culas de amido, provavelmente atrav?s das hidroxilas de ambos que estabeleceram liga??es de hidrog?nio permitindo a imobiliza??o das antocianinas no filme, o que foi vantajoso visto a instabilidade das antocianinas. A matriz polim?rica adicionada de a?a? liofilizado teve sua espessura aumentada o que provocou aumento da PVA, redu??o da solubilidade em ?gua e da atividade de ?gua, sendo estes dois ?ltimos par?metros vantajosos para uma embalagem de alimentos. Quanto ?s propriedades mec?nicas, observou-se que a for?a de ruptura e a deforma??o na perfura??o foram reduzidas. No teste de tra??o houve redu??o da tens?o na ruptura e no m?dulo de elasticidade. A deforma??o na tra??o apresentou maior resultado, indicando que a adi??o do a?a? liofilizado aumentou a flexibilidade do filme. Quanto a cor, o filme apresentou colora??o escura compat?vel com o fruto, com potencial uso para embalagem de alimentos escuros.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-06-21T17:20:01Z No. of bitstreams: 1 2015 - Vinicius Olivieri Rodrigues Gomes.pdf: 8391173 bytes, checksum: b3790798dbf591af7fcc8e63ad01c306 (MD5) / Made available in DSpace on 2017-06-21T17:20:01Z (GMT). No. of bitstreams: 1 2015 - Vinicius Olivieri Rodrigues Gomes.pdf: 8391173 bytes, checksum: b3790798dbf591af7fcc8e63ad01c306 (MD5) Previous issue date: 2015-07-22 / The need of producing polymeric artifacts increasingly powerful and versatile but which have increasingly lower biodegradation times motivates the scientific community to seek combinations of natural and synthetic polymers in order to meet both aspects. The manufacture of the blend LDPE/TPS Starch / Chitosan aims to go against that objective. The biodegradation occurs mostly in the soil. Trying to understand the dynamics of the biodegradation process in soil, this paper monitored the effects caused by deposition of the blend, analyzing different parameters, such as organic carbon, organic matter and microbial carbon, indicating levels of soil quality.The blends were prepared with different concentrations of chitosan, with values set to 0, 7, 5 and 15% of total mass and buried in pure soil and soil treated with humus. The analysis periods were 10, 40, 70, 100 and 130 days, with samples being exposed to the environment. Infrared analysis were performed using Fourier transform, X-ray diffraction, scanning electron microscopy with spectroscopy dispersive energy before and after biodegradation mass loss, after the biodegradation process of the blends. Organic carbon, organic matter, microbial carbon, pH and moisture in the soil.The results obtained after analysis in blend showed that with the passage of time, the biodegradation process happened, considering that carbon levels dropped considerably and oxygen were increased in accordance with the EDS analysis. The FTIR analysis confirmed this fact by showing that there was an intese oxidative process, especially in the initial 70 days in all samples. The X-RD analysis showed that there was a variationin crystallinity, but always with a decrease of this paramenter. The weight loss was also significant and progressive in all samples. Soil results showed that the same is resilient and can recover its characteristics during the biodegradation process. At the beginning of the experiment, especially in the first 40 ays, all evaluated paramenters declined considerably, but returned to baseline levels and maintained these values by the end of the experiment. Experimental design was made and it showed that none of the dependent variables influenced the biodegradion process. / A necessidade de produzir artefatos polim?ricos cada vez mais vers?teis e ?performantes? e que apresentem caracter?sticas de biodegrada??o cada vez mais acentuadas tem motivado a comunidade cient?fica a buscar combina??es entre pol?meros sint?ticos e naturais com o objetivo de atender esses aspectos. O desenvolvimento de blendas de polietileno de baixa densidade/amido termopl?stico/quitosana (PEBD/TPS/Q) e de amido termopl?stico/quitosana (TPS/Q) visou ir de encontro a tal objetivo, procurando entender a din?mica do processo biodegradativo no solo. O presente trabalho acompanhou os efeitos causados pela deposi??o dessas blendas, analisando diferentes par?metros, como carbono org?nico total, massa org?nica total e carbono de biomassa microbiana, que indicam n?veis de qualidade do solo, al?m da perda de massa ap?s cada per?odo de biodegrada??o. As blendas de PEBD/TPS/Q e TPS/Q foram preparadas com diferentes concentra??es de quitosana, com valores definidos em 0, 7,5 e 15% da massa total e enterradas em solo puro e solo tratado com h?mus. Os per?odos de an?lise de biodegrada??o foram de 10, 40, 70, 100 e 130 dias, com as amostras sendo expostas ao ambiente. As blendas foram analisadas por espectroscopia de infravermelho com transformada de Fourier (FTIR), difra??o de raios-X (DRX), microscopia eletr?nica de varredura com espectroscopia de energia dispersiva (MEV/EDS), e quanto a perda de massa, antes e ap?s o processo de biodegrada??o. Tamb?m foram realizadas an?lises de carbono org?nico total, massa org?nica total, concentra??o de carbono de biomassa microbiana, pH e umidade dos solos utilizados. Os resultados comprovaram o processo biodegradativo das blendas com o passar do tempo, tendo em vista a diminui??o dos n?veis de carbono e aumento consider?vel dos n?veis de oxig?nio das blendas de PEBD/TPS/Q, de acordo com as an?lises de FTIR e EDS, e total biodegrada??o das blendas de TPS/Q. As bandas de FTIR comprovaram a ocorr?ncia do processo oxidativo, principalmente nos 70 dias iniciais, nas amostras de PEBD/TPS/Q. As an?lises de DRX mostraram que houve uma varia??o da cristalinidade, com a tend?ncia de diminui??o deste par?metro. A perda de massa tamb?m foi consider?vel e progressiva para todas as amostras. Os resultados de an?lise das amostras de solo mostraram o poder de recupera??o da atividade microbiana dos mesmos (resili?ncia) durante o processo biodegradativo. No per?odo inicial do experimento, em especial nos primeiros 40 dias, todos os par?metros avaliados sofreram decaimento de seus valores, por?m retornaram aos patamares iniciais e mantiveram esses valores at? o final do experimento. O planejamento experimental realizado mostrou que nenhuma das vari?veis independentes influenciou no processo de bioatividade do solo.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-20T13:13:06Z No. of bitstreams: 1 2013 - Mauro Meliga Wysard Junior.pdf: 3560905 bytes, checksum: 2826a580c7e2ec9ebe3a9e07daacb4f7 (MD5) / Made available in DSpace on 2017-01-20T13:13:06Z (GMT). No. of bitstreams: 1 2013 - Mauro Meliga Wysard Junior.pdf: 3560905 bytes, checksum: 2826a580c7e2ec9ebe3a9e07daacb4f7 (MD5) Previous issue date: 2013-10-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The need to reduce environmental impacts while maintaining economic efficiency of various processes has motivated research to develop cheaper and sustainable technologies, to replace those already employed in the industrial sectors. Thus, recycling and utilization of natural materials such as coconut fiber or marine animal shells, is envisioned as an alternative to reduce the environmental impact and at the same time the use of these components in industrial processes reduces operational costs. In this context the biosorbents are included, such as coconut fibers and chitosan, which have high applicability to processes for removing metal ions, and are widely available at low cost. In addition, the problem found in the recovery of these adsorbents and adsorbate after the adsorption process can be bypassed by setting biosorbents in polymeric matrixes, obtaining larger parts, which facilitates the separation steps. Thus, this work aims to develop porous composite adsorbent properties, from the physical mixture of maleic anhydride polyethylene (PE-g-MA), coconut fiber (FC), chitosan (Q), and sodium chloride (NaCl) used as porogen agent), and assess the capacity of these new porous composite in the removal of metallic chromium (III) Ion, since this is a residue present in large industrial activities such as electroplating. The porosity of this material was obtained by leaching of NaCl, present in the composition of composite material. For this assessment, we conducted a trial planning, where could be evaluate the influence of particle size of coconut fiber and the amount of chitosan on adsorption process efficiency, as well as the pH of an aqueous solution containing the chromium (III) adsorbate. With the results could be concluded that the model used in planning was valid for the evaluation of the significance of these variables, as well as the trend of better removal of chromium (III), which took place in the higher pH values (between 6 and 7) and in the presence of increased amounts of chitosan (7.5-8.6 g). The granulometric size range of coconut fiber that was more favorable was between 0.097-0.142 mm. Analyzing these porous composites by spectroscopy in the infrared (FTIR), X-ray diffraction (XRD), water absorption and scanning electron microscopy (SEM), you can see and confirm the strong interaction between the components of the mixture, possibly by interfering in the process efficiency of adsorption of chromium / A necessidade de reduzir impactos ambientais e ao mesmo tempo manter a efici?ncia econ?mica de diversos processos, vem motivando o meio acad?mico a realizar pesquisas voltadas para o desenvolvimento de novas tecnologias mais baratas e sustent?veis, que possam substituir as j? empregadas nos setores industriais. Desta forma, a reciclagem e a utiliza??o de mat?rias-primas naturais como a casca de coco e carapa?as de animais marinhos ? vislumbrada como uma alternativa para a redu??o do impacto ambiental, e ao mesmo tempo, pela utiliza??o desses componentes em processos industriais com a finalidade de reduzir custos operacionais. Neste contexto encontram-se os biossorventes naturais, como a fibra de coco e a quitosana, que apresentam alta aplicabilidade em processos de remo??o de ?ons met?licos, e uma grande disponibilidade a baixo custo. Al?m disso, o problema encontrado na recupera??o desses adsorventes e do adsorvato ap?s o processo de adsor??o pode ser contornado pela fixa??o dos biossorventes em matrizes polim?ricas, obtendo-se pe?as de maior volume, o que facilita as etapas de separa??o. Assim, este trabalho teve como objetivo desenvolver comp?sitos porosos com propriedades adsorventes, a partir da mistura f?sica de polietileno graftizado com anidrido maleico (PE-g-MA), fibra de coco (FC), quitosana (Q) e cloreto de s?dio (NaCl) utilizado como agente porog?nico), e avaliar a capacidade de adsor??o desses novos comp?sitos porosos na remo??o do ?on met?lico cromo (III), j? que este, ? um res?duo presente em grandes atividades industriais, como a galvanoplastia. Com esta finalidade, foi realizado um planejamento experimental, onde foi avaliada a influ?ncia do tamanho das part?culas de fibra de coco e da quantidade de quitosana na efici?ncia do processo de adsor??o, assim como o pH da solu??o aquosa contendo o adsorvato cromo (III). Com os resultados pode-se concluir que o modelo usado no planejamento experimental foi v?lido para a avalia??o da signific?ncia dessas vari?veis, como para as melhores condi??es de remo??o do cromo (III), as quais aconteceram nos valores mais elevados de pH (entre 6 e 7) e na presen?a de maiores quantidades de quitosana (7,5-8,6 g). A faixa granulom?trica da fibra de coco que se mostrou mais favor?vel foi de 0,097-0,142 mm. Analisando esses comp?sitos porosos por espectroscopia na regi?o do infravermelho (FTIR), difra??o de raios-X (DRX), absor??o de ?gua e microscopia eletr?nica de varredura (MEV), p?de-se constatar e confirmar a forte intera??o ocorrida entre os componentes da mistura, possivelmente, interferindo na efici?ncia do processo de adsor??o do cromo (III).

Made available in DSpace on 2014-12-17T14:07:07Z (GMT). No. of bitstreams: 1 LuizFMC_TESE.pdf: 3268756 bytes, checksum: e846724b8b5adbbee4ec9a2ecaf76796 (MD5) Previous issue date: 2011-06-20 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The use of raw materials from renewable sources for production of materials has been the subject of several studies and researches, because of its potential to substitute petrochemical-based materials. The addition of natural fibers to polymers represents an alternative in the partial or total replacement of glass fibers in composites. In this work, carnauba leaf fibers were used in the production of biodegradable composites with polyhydroxybutyrate (PHB) matrix. To improve the interfacial properties fiber / matrix were studied four chemical treatments to the fibers..The effect of the different chemical treatments on the morphological, physical, chemical and mechanical properties of the fibers and composites were investigated by scanning electron microscopy (SEM), infrared spectroscopy, X-ray diffraction, tensile and flexural tests, dynamic mechanical analysis (DMA), thermogravimetry (TGA) and diferential scanning calorimetry (DSC). The results of tensile tests indicated an increase in tensile strength of the composites after the chemical treatment of the fibers, with best results for the hydrogen peroxide treated fibers, even though the tensile strength of fibers was slightly reduced. This suggests a better interaction fiber/matrix which was also observed by SEM fractographs. The glass transition temperature (Tg) was reduced for all composites compared to the pure polymer which can be attributed to the absorption of solvents, moisture and other low molecular weight molecules by the fibers / O uso de mat?rias-primas de fontes renov?veis para a produ??o de materiais vem sendo objeto de diversos estudos e pesquisas, devido ao seu potencial na substitui??o de derivados petroqu?micos. A adi??o de fibras vegetais a pol?meros representa uma alternativa na substitui??o parcial ou total de fibras de vidro em comp?sitos. Neste trabalho, fibras da folha de carna?ba (Copernicia prun?fera) foram utilizadas na produ??o de comp?sitos biodegrad?veis com matriz de polihidroxibutirato (PHB). Para melhorar as propriedades interfaciais fibra/matriz foram estudados quatro tratamentos qu?micos, para as fibras. O efeito dos diferentes tratamentos qu?micos nas propriedades morfol?gicas, f?sicas, qu?micas e mec?nicas das fibras e dos comp?sitos foram investigados por microscopia eletr?nica de varredura (MEV), espectroscopia no infravermelho, difra??o de raios-X, ensaios mec?nicos de tra??o e flex?o, an?lise din?mico-mec?nica (DMA) e an?lises t?rmicas por termogravimetria (TG) e calorimetria explorat?ria diferencial (DSC). Os resultados dos ensaios de tra??o dos comp?sitos indicaram um acr?scimo de resist?ncia ? tra??o ap?s modifica??o qu?mica das fibras, sendo o melhor resultado obtido com o tratamento de per?xido de hidrog?nio, mesmo havendo uma pequena redu??o na resist?ncia ? tra??o das fibras tratadas. Isto indica uma melhor intera??o entre as fibras e a matriz polim?rica que foi tamb?m observada nas imagens de microscopia eletr?nica de varredura. A temperatura de transi??o v?trea (Tg) foi reduzida para todos os comp?sitos em rela??o ao pol?mero puro o que foi atribu?do a absor??o de solventes, umidade e outras mol?culas de baixo peso molecular pelas fibras

Made available in DSpace on 2014-12-17T14:07:16Z (GMT). No. of bitstreams: 1 EdnaMSC_DISSERT.pdf: 4754889 bytes, checksum: 7ba8ec4a5f3d11921ca74b85b2fe0b3b (MD5) Previous issue date: 2013-07-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This employment has the function the utilization of mango seeds Tommy Atkins, like starch source to obtain biopolymers and fibers source and nanowhiskers cellulose also, that will be use like reinforcing fillers in micro and nanobiocomposites polymeric. The fibers in natura removed from tegument mango seed were characterized, as weel as the treated fibers and nanowhiskers of cellulose extracted from them. The starch extracted from seed s almond showed a good performance (32%) and a high purity. The chemicals analyzes, of crystallinity and morphological of the fibers in natura, treated fibers and nanowhiskers of cellulose confirmed the efficacy of the chemical treatement performed to remove amorphous constituents (hemicellulose and lignina). The thermoplastic starch (TPS) obtained from two sources, corn starch and starchy material mango, was produced in a twin screw extruder with compositon mass of 62,5% of starch, 9,4% of water and 28,1% of glycerol. The starch material mango was the main objective of this work for the production of biodegradable materials, and the starch corn was utilized during the production stage to evaluate the processability of the starch and use as parameter for comparison, according of being a conventional source for obtaining conventional comercial starch. The incorporation of fibers (6% in mass) and nanowhiskers cellulose (1% in mass) in matrix of TPS to obtain composite and nanocomposite, respectively, it was performed in single screw extruder. The biocomposites and bionanocomposites polymeric were obtained and the TPS from starchy material mango presented better results of thermal and mechanicals properties when compared to TPS corn starch. Concludes that the sediment generated of the agroindustrial processing mango used presents potencial to producing of biodegradables materials / Este trabalho apresenta como objetivo a utiliza??o de caro?os da manga Tommy Atkins, como fonte de amido para obten??o de biopol?meros e, tamb?m, como fonte de fibras e nanowhiskers de celulose, que foram utilizadas como cargas refor?antes em micro e nanobiocomp?sitos polim?ricos. As fibras in natura removidas do tegumento do caro?o de manga foram caracterizadas, bem como as fibras tratadas e nanowhiskers de celulose extra?dos a partir delas. O amido extra?do das am?ndoas do caro?o apresentou um bom rendimento (32%) e elevado grau de pureza. As an?lises qu?micas, de cristalinidade e morfol?gicas das fibras in natura, fibras tratadas e nanowhiskers de celulose confirmaram a efic?cia do tratamento qu?mico realizado em remover os constituintes amorfos (hemicelulose e lignina). O amido termopl?stico (TPS) obtido de duas fontes, amido de milho e material amil?ceo de manga, foi produzido em extrusora rosca dupla com a composi??o em massa de 62,5% de amido, 9,4% de ?gua e 28,1% de glicerol. O material amil?ceo de manga foi o objetivo principal deste trabalho para produ??o de materiais biodegrad?veis, e o amido de milho foi utilizado durante a etapa de produ??o para avaliar a processabilidade do amido e utilizar como par?metro de compara??o, em fun??o de ser uma fonte convencional de obten??o de amido comercial. A incorpora??o das fibras (6% em massa) e nanowhiskers de celulose (1% em massa) em matriz de TPS para obter comp?sitos e nanocomp?sitos, respectivamente, foi realizada em extrusora monorosca. Os biocomp?sitos e bionanocomp?sitos polim?ricos foram obtidos e os TPS do material amil?ceo de manga apresentaram melhores resultados de propriedades t?rmicas e mec?nicas quando comparados aos TPS de amido de milho. Concluiu-se que os res?duos gerados do processamento agroindustrial da manga utilizados apresentaram potencial para a produ??o de materiais biodegrad?veis

Made available in DSpace on 2014-12-17T14:16:27Z (GMT). No. of bitstreams: 1 AliceRO_DISSERT.pdf: 2104659 bytes, checksum: 208850f5293dd4764037ec4c490d3636 (MD5) Previous issue date: 2011-12-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Methotrexate (MTX) is a drug used in the chemotherapy of some kind of cancers, autoimmune diseases and non inflammatory resistant to corticosteroids uveits. However, the rapid plasmatic elimination limits its therapeutic success, which leads to administration of high doses to maintain the therapeutic levels in the target tissues, occurring potential side effects. The aim of this study was to obtain spray dried biodegradable poly-lactic acid co-glycolic acid (PLGA) microparticles containing MTX. Thus, suitable amounts of MTX and PLGA were dissolved in appropriate solvent system to obtain solutions at different ratios drug/polymer (10, 20, 30 and 50% m/m). The physicochemical characterizing included the quantitative analysis of the drug using a validate UV-VIS spectrophotometry method, scanning electron microscopy (SEM), infrared spectrophotometry (IR), thermal analyses and X-ray diffraction analysis. The in vitro release studies were carried out in a thermostatized phosphate buffer pH 7.4 (0.05 M KH2PO4) medium at 37?C ? 0.2 ?C. The in vitro release date was subjected to different kinetics release models. The MTX-loaded PLGA microparticles showed a spherical shape with smooth surface and high level of entrapped drug. The encapsulation efficiency was greater then 80%. IR spectroscopy showed that there was no chemical bond between the compounds, suggesting just the possible occurrence of hydrogen bound interactions. The thermal analyses and X-ray diffraction analysis shown that MTX is homogeneously dispersed inside polymeric matrix, with a prevalent amorphous state or in a stable molecular dispersion. The in vitro release studies confirmed the sustained release for distinct MTX-loaded PLGA microparticles. The involved drug release mechanism was non Fickian diffusion, which was confirmed by Kornmeyer-Peppas kinetic model. The experimental results demonstrated that the MTX-loaded PLGA microparticles were successfully obtained by spray drying and its potential as prolonged drug release system. / O metotrexato (MTX) ? um f?rmaco utilizado na quimioterapia de alguns tipos de c?ncer, doen?as autoimunes e uve?tes n?o inflamat?rias resistentes aos corticoster?ides. No entanto, sua r?pida elimina??o plasm?tica limita o sucesso terap?utico, levando ? necessidade de altas doses para manuten??o da concentra??o efetiva no tecido alvo, ocasionando o potencial surgimento de rea??es adversas. O objetivo principal desse estudo foi obter um sistema microparticulado biodegrad?vel ? base de ?cido poli (?cido l?tico-co-?cido glic?lico) (PLGA) por spray drying para libera??o prolongada do MTX. Para isso, quantidades distintas de MTX e PLGA foram dissolvidas em sistema solvente adequado para obter solu??es com diferentes propor??es de f?rmaco em rela??o ao pol?mero (10, 20, 30 e 50% m/m). A caracteriza??o f?sicoqu?mica incluiu an?lise quantitativa do f?rmaco incorporado na matriz polim?rica por espectrofotometria UV-VIS em 303nm previamente validada, microscopia eletr?nica de varredura (MEV), espectrofotometria de infravermelho (IV), an?lises t?rmicas e difra??o de raios-X (DRX). O perfil de libera??o in vitro do f?rmaco nas micropart?culas foi realizado em tamp?o fosfato (0.05 M KH2PO4) em banho termostatizado 37 ?C ? 0.2 ?C. Os dados obtidos do estudo de libera??o in vitro foram submetidos a diferentes modelos cin?ticos de libera??o. As micropart?culas de PLGA contendo o MTX apresentaram a forma esf?rica, uniforme, com superf?cie aparentemente lisa. O n?vel de efici?ncia de encapsula??o foi superior a 80%. A espectroscopia na regi?o do infravermelho demonstrou que n?o ocorreu liga??o qu?mica entre os componentes dos sistemas, no entanto foi observado forte intera??o entre o MTX e PLGA indicando prov?vel ocorr?ncia de pontes de hidrog?nio. An?lise XII t?rmica e DRX demonstraram que o MTX est? distribu?do na matriz polim?rica com a preval?ncia do estado amorfo ou em dispers?o molecular. O estudo de libera??o in vitro confirmou o perfil de libera??o prolongada para as diferentes micropart?culas. O mecanismo de libera??o envolvido foi por difus?o n?o Fickiana, ao qual foi determinado a partir do modelo cin?tico de Kornmeyer- Peppas. Os resultados experimentais demonstraram o sucesso na obten??o das micropart?culas de PLGA contendo o MTX por spray drying e seu potencial como sistema de libera??o prolongada do f?rmaco.