Submitted by VIVIANE ENDO null (endo_vica@hotmail.com) on 2016-03-09T19:43:01Z No. of bitstreams: 1 Tese_Viviane_Endo.pdf: 2381814 bytes, checksum: 1717fe0a2a655707a2aa6da8a9f8467a (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-03-10T19:32:22Z (GMT) No. of bitstreams: 1 endo_v_dr_jabo.pdf: 2381814 bytes, checksum: 1717fe0a2a655707a2aa6da8a9f8467a (MD5) / Made available in DSpace on 2016-03-10T19:32:22Z (GMT). No. of bitstreams: 1 endo_v_dr_jabo.pdf: 2381814 bytes, checksum: 1717fe0a2a655707a2aa6da8a9f8467a (MD5) Previous issue date: 2016-02-16 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A cana-de-açúcar tem papel importante no agronegócio brasileiro para a produção de etanol e açúcar. A palha da cana-de-açúcar é um resíduo orgânico pobre em sacarose para produção de etanol e de baixo valor nutritivo para a alimentação animal. Devido a isso, o processo de queima dos canaviais ocorre em larga escala com intuito de facilitar a colheita da cana-de-açúcar, além de limpar o canavial para a próxima safra. Entretanto, a queima causa danos à saúde e impacto ambiental. No estudo foram avaliados dois fatores da cana-de-açúcar: a influência da palha e a influência dos tempos de preparo da calda de hidróxido de cálcio (Ca(OH)2) antes da hidrólise da cana-de-açúcar. Os parâmetros avaliados neste estudo foram: composição bromatológica, temperatura e pH da cana-de-açúcar, digestibilidade de nutrientes, desempenho de vacas leiteiras e uso de imagens de microscopia eletrônica de varredura (MEV) da cana-de-açúcar antes e após a digestão in vitro. O primeiro estudo foi um arranjo fatorial 2 x 5 [cana-de-açúcar com ou sem palha e cinco tempos de preparo da calda de Ca(OH)2 antes da hidrólise da cana-de-açúcar (72, 48, 24, 0,5 horas e sem preparo)]. No segundo estudo foi avaliado a digestibilidade in vitro dos nutrientes em um delineamento inteiramente casualizado, com cinco tratamentos: cana-de-açúcar fresca sem palha, HPT0,5 (cana-de-açúcar hidrolisada com palha e a calda preparada 0,5 horas antes da hidrólise), HPT72 (cana-de-açúcar hidrolisada com palha e a calda preparada 72 horas antes da hidrólise), HT0,5 e HT72, cana-de-açúcar hidrolisada sem palha usando os mesmos procedimentos de preparo da calda na cana-de-açúcar com palha. Posteriormente, utilizou-se um delineamento em quadrado latino 5 x 5 (cinco vacas em lactação e cinco tratamentos) para estudo de desempenho. Imagens de MEV foram feitas como complemento para visualização da cana-de-açúcar com e sem digestão in vitro. Como resultados, a cana-de-açúcar fresca sem palha e hidrolisada com palha e a calda preparada 72 horas antes apresentou menor teor de fibra em detergente neutro (FDN). O pH da cana-de-açúcar hidrolisada, devido à presença do agente alcalinizante foi maior em comparação à cana-de-açúcar fresca independente da palha. A temperatura foi influenciada pela palha, apresentando-se maior quando esta estava presente. Em relação à digestibilidade dos nutrientes, a cana-de-açúcar hidrolisada com palha, quando comparada à hidrolisada sem palha, apresentou menor digestibilidade in vitro de matéria seca (MS) e maior digestibilidade in vitro da FDN. Para o desempenho das vacas, houve menor consumo de MS para a cana-de-açúcar com palha em comparação à cana-deaçúcar sem palha. A produção de leite manteve-se constante entre os tratamentos, assim como a sua composição. Nas imagens da MEV, algumas pequenas partículas de cana-de-açúcar que foram observadas nas amostras não digerida, após a digestão in vitro parecem ter sofrido alguma digestão. O que permaneceu foram partículas maiores, ou seja, partículas indigestíveis. A utilização da cana-de-açúcar com palha e a calda de Ca(OH)2 preparada 72 horas antes da hidrólise é recomendada devido à melhor eficiência alimentar das vacas, além de facilitar a mão-de-obra. / Sugarcane has an important role in agribusiness because of ethanol and sugar production. Straw of sugarcane is an organic residue, it has low nutritional value to animal feed and a poor sucrose content which is used to produce ethanol. Because of this, burning of the sugarcane is performed on a large scale aiming to facilitate the sugarcane harvest, besides cleaning the sugarcane fields for the next crop. Burning, however, is not safe for health and causes harmful environmental impact. The study evaluated two sugarcane factors: the influence of straw and the time of lime preparation on the sugarcane hydrolysis. The variables analyzed on this study were: chemical composition, temperature and pH of sugarcane, nutrient digestibility, performance of dairy cows and the use of scanning electron microscopy (SEM) images of sugarcane before and after in vitro digestion. First study was arranged as a factorial 2 x 5 [sugarcane with or without straw and five times of the lime preparation before hydrolysis of sugarcane (72, 48, 24, 0.5 hours and no lime used)]. The lime used was calcium hydroxide (Ca(OH)2. In the second study the in vitro digestibility of nutrients was evaluated and arranged as a completely randomized design with five treatments: fresh sugarcane without straw, HST0.5 (hydrolyzed sugarcane with straw and the lime prepared 0.5 hours before the hydrolysis), HST72 (hydrolyzed sugarcane with straw and the lime prepared 72 hours before the hydrolysis), HT0.5 (hydrolyzed sugarcane without straw and the lime prepared 0.5 hours before the hydrolysis) and HT72 (hydrolyzed sugarcane without straw and the lime prepared 72 hours before the hydrolysis). Posteriorly, a Latin square design 5 x 5 five lactating cows and five treatments was arranged for performance of dairy cows. As complement, SEM images of sugarcane before and after the in vitro digestion were done. As results, fresh sugarcane without straw and hydrolyzed with straw and the lime prepared 72 hours in advance presented lower neutral detergent fiber (NDF) content. The pH of hydrolyzed sugarcane was higher compared to fresh sugarcane, due to the presence of the alkalizing agent, regardless of straw. Temperature was higher when the straw was present. Regarding the digestibility of nutrients, sugarcane with straw showed lower in vitro digestibility of dry matter (DM) and higher in vitro digestibility of NDF compared with hydrolyzed sugarcane. For the cow’s performance, a lower DM intake was observed for sugarcane with straw compared with sugarcane without straw. Milk production was similar among treatments, as well as its composition. Providing sugarcane with straw and the lime of Ca(OH)2 prepared 72 hours before hydrolysis of sugarcane is recommended because it provided better feed efficiency to the cows. Additionally, it facilitates the labor. / CNPq: 151452/2012-1

Orientador: Marcos Silveira Buckeridge / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-12T18:38:24Z (GMT). No. of bitstreams: 1 Lisboa_CesarGustavoSerafim_D.pdf: 1945488 bytes, checksum: 831197d663c65044a02bdfd7ba13598f (MD5) Previous issue date: 2008 / Resumo: Aplicações biotecnológicas de polissacarídeos de plantas: uma estratégia sustentável para a produção em demanda. Atualmente, a busca por novas fontes de materiais pode levar ao depósito de patentes. Isto é importante para que novos produtos, que apresentem características inovadoras, potencial de redução de custos, rotas de produção ambientalmente corretas, partição de benefícios e, finalmente, possibilitem a exploração de novos mercados de maneira sustentável. Nesse contexto, o presente trabalho teve como objetivo avaliar o potencial de uso de polissacarídeos de plantas de diferentes fontes nos setores de alimentos, farmacosméticos e papel. Os resultados são apresentados na forma de um artigo e 4 patentes. Os xiloglucanos de sementes de espécies nativas de plantas (Hymenaea courbaril) e de plântulas de eucalipto foram aplicados no processo de confecção do papel, demonstrando que suas propriedades mecânicas podem ser melhoradas. Resultados similares foram obtidos com galactomananos de sementes de Sesbania virgata e Dimorphandra mollis. O xiloglucano de H. courbaril foi estudado mais profundamente e demonstrou-se que pode ser também aplicado em cosméticos, pois não é citotóxico, é capaz de espessar formulações e interfere na produção de colágeno pela pele. As propriedades reológicas do galactomanano de D. mollis foram estudadas em comparação a outros galactomananos já utilizados na indústria. Demonstrou-se que ele é apropriado para várias aplicações em alimentos. Como um todo, nossos resultados indicam que tanto os polissacarídeos de sementes de espécies nativas como o de eucalipto podem ser utilizados em várias aplicações de tal forma que possam fazer parte de programas de uso sustentável da biodiversidade, levando a benefícios tecnológicos e também sociais. / Abstract: Biotechnological applications of plant polysaccharides: a sutainable strategy for production and demand. Nowdays, the search for new sources of materials can lead to new patent deposits. This is important because new products that display innovative features, cost reduction potential, environmentally clean production routes, partition of benefits and finally, may turn possible to explore differential market shares. These may be excellent socio-environmental and market shares for biotechnology companies. In this context, the present work aimed at evaluating the potential of use of plant polysaccharides from different sources in the food, farmacosmetic and paper industrial sectors. In the present work, we present studies that focus on the use of seed polysaccharides on applications on paper, cosmetics and food industries. The results are presented in the form of one article and 4 patents. The xyloglucan from seeds of native tropical tree species (Hymenaea courbaril - jatobá, Copaifera langsdorffii - copaiba) and from seedlings of Eucalyptus grandis (eucalypt) were applied to paper making and we demonstrated that several properties of paper can be improved by using these xyloglucans during preparation. Similar results were obtained with galactomann ans from Sesbania virgata and Dimorphandra mollis, two fast-growing legume trees. The polymers increased paper resistance to mechanical stress so that they can be applied for applications where more resistant papers (such as rapping paper) are used. The xyloglucan from H. courbaril was studied more deeply, demonstrating that it can be applied in cosmetics as it is not cytotoxic and can be used to improve skin biochemistry such as collagen production. Galactomannan from D. mollis was studied from the rheological point of view and its properties were compared with other commercially used galactomannans. Our results showed that D. mollis galactomannan is appropriate to several applications in food industries. As a whole, our results indicate that both, native seeds and seeds of eucalyptus, might be used in several industrial applications so that these might be used as part of programs of sustainable use of biodiversity, leading to social and technological benefits to society. / Doutorado / Biologia Celular / Doutor em Biologia Celular e Estrutural

Cellulose and hemicellulose account for a large portion of the world‘s plant biomass. In nature, these polysaccharides are intertwined forming complex materials that require multiple enzymes to degrade them. Multi-enzyme complexes (MECs) consist of a number of enzymes working in close proximity and synergistically to degrade complex substrates with higher efficiency than individual enzymes. The cellulosome is a cellulolytic MEC produced by anaerobic bacteria that has been studied extensively since its discovery in 1983. The aim of this study was to purify a cellulolytic and/or hemicellulolytic MEC from an aerobic bacterium of the Bacillus genus. Several bacterial isolates were identified using morphological characteristics and 16S rDNA sequencing, and screened for their ability to degrade cellulose and xylan using a MEC. The isolate that produced a high molecular weight protein fraction with the greatest ability to degrade Avicel®, carboxymethyl cellulose (CMC) and birchwood xylan was identified as Bacillus subtilis SJ01. An optimised growth medium, consisting of vitamins, trace elements, birchwood xylan (as the carbon source), and yeast and ammonium sulphate (as the nitrogen sources), increased the production of CMCase and xylanase enzymes from this bacterium. The removal of a competing bacterial strain from the culture and the inhibition of proteases also increased enzyme activities. A growth curve of B. subtilis SJ01 indicated that xylanase production was highest in early stationary growth phase and thus 84 hours was chosen as the best cell harvesting time. To purify the MECs produced by B. subtilis SJ01 size-exclusion chromatography on a Sephacryl S-400 column was used. It was concluded that (for the purposes of this study) the best method of concentrating the culture supernatant prior to loading onto Sephacryl S-400 was the use of ultrafiltration with a 50 kDa cut-off membrane. Two MECs, named C1 and C2 of 371 and 267 kDa, respectively, were purified from the culture supernatant of B. subtilis SJ01. Electrophoretic analysis revealed that these MECs consisted of 16 and 18 subunits, respectively, 4 of which degraded birchwood xylan and 5 of which degraded oat spelt xylan. The MECs degraded xylan substrates (C1: 0.24 U/mg, C2: 0.14 U/mg birchwood xylan) with higher efficiency than cellulose substrates (C1: 0.002 U/mg, C2: 0.01 U/mg CMC), and could therefore be considered xylanosomes. Interestingly, the MECs did not bind to insoluble birchwood xylan or Avicel® and did not contain glycosylated proteins, which are common features of cellulosomes. This study is, therefore, important in revealing the presence of MECs that differ from the cellulosome and that may have particular application in industries requiring high xylanase activity, such as the paper and pulp industry. The abundant genetic information available on B. subtilis means that this organism could also be used for genetic engineering of cellulolytic/hemicellulolytic MECs.

Given the volatile, generally high price of crude oil, as well as environmental concerns associated with its use as a fuel, development of alternative energy sources is currently of considerable interest. Lignocellulose-derived energy has the potential to supplant traditional fossil fuels in the future because of its economic and environmental advantages. Lignocellulosic biomass is abundant and renewable. Lignocellulose is primarily composed of cellulose, hemicellulose and lignin, which can be converted by acid hydrolysis to simple sugars used in fermentation to produce biofuels. In this study, hemicellulose was hydrolyzed with different concentrations of hydrochloric acid at different temperatures. The resulting components were analyzed by high performance liquid chromatography (HPLC). The hydrolysis of cellulose was similarly characterized, with two additional parameters, the degree of polymerization (DP) and the crystallinity index (CrI), which were analyzed by Ubbelohde viscometer and X-ray diffraction respectively. The experimental results indicate that the hydrolysis rate of hemicellulose and the generation rate of furfural and 5-hydroxymethylfurfural (HMF) increased with increasing hydrochloric acid concentrations and reaction temperatures. In the selected five monosaccharides, xylose, glucose, mannose, arabinose and galactose, xylose has the highest hydrolysis rate and the accumulation of furfural during xylose hydrolysis is also the highest. Moreover, the hydrolysis rate of cellulose and the generation rate of glucose also increased with increasing hydrochloric acid concentrations and reaction temperatures. DP and CrI, both decreased when the cellulose was treated in concentrated hydrochloric acid. The rate of change of DP increased with the concentrations of acid and the reaction temperatures. The change rate of CrI increases by increasing concentration of acid and the temperature when it is above 0℃, while the CrI index decrease sharply when the reaction temperature was kept below 0℃. Experimental results also show that the hydrolysis rate of cellulose is much lower than that of hemicellulose.

Orientador: Katia Tannous / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-27T02:38:53Z (GMT). No. of bitstreams: 1 Baroni_EricodeGodois_M.pdf: 4653492 bytes, checksum: abc40b6bb4cc970c83b082daf28c5195 (MD5) Previous issue date: 2015 / Resumo: Este trabalho tem como objetivo realizar o estudo cinético da pirólise do endocarpo do fruto do tucumã mediante termogravimetria em atmosfera de nitrogênio para análise da decomposição térmica, assim como a obtenção dos parâmetros cinéticos, aplicando modelos cinéticos globais e de reações independentes e paralelas. A energia de ativação, fator pré-exponencial e ordem de reação foram calculados utilizando dois conjuntos de experimentos. O primeiro, obtido de Nascimento (2012), utilizando taxas de aquecimento de 5°C/min a 20°C/min e diâmetro médio de 499 µm. O segundo conjunto de dados termogravimétricos foi obtido de modo a avaliar a influência do diâmetro de partícula (de 128,04 µm a 499,55 µm) considerando taxa de aquecimento de 10°C/min e da taxa de aquecimento (de 2,5°C/min a 15°C/min) com diâmetro médio de 128,04 µm. A partir do primeiro conjunto de dados, foram calculados os parâmetros cinéticos por meio de três modelos de reação isoconversionais global (Ozawa-Flynn-Wall, Coats-Redfern modificado e Friedman), em que foram calculadas energias de ativação entre 149 kJ/mol e 159 kJ/mol, fator pré-exponencial de aproximadamente 13 ?1-ns-1 e as ordens de reação de aproximadamente 6. A função de conversão foi definida como correspondente a um mecanismo reacional de n-ésima ordem, baseando-se em onze diferentes equações disponíveis na literatura. Para esse conjunto de dados, o modelo de reações independentes e paralelas (MRIP) foi aplicado considerando reações para hemicelulose, celulose e lignina. Adicionalmente, com o segundo conjunto de dados, o MRIP foi aplicado considerando três e quatro reações, em que foi considerada uma reação adicional associada às reações secundárias de decomposição. A aplicação do MRIP de três reações a partir de dados de Nascimento (2012), gerou desvios relativos próximos aos obtidos com os dados deste trabalho (~4% e ~3%, respectivamente). Entretanto, a aplicação do MRIP de quatro reações gerou desvios relativos ainda menores (~2%), em que energias de ativação, de aproximadamente 128 kJ/mol, 198 kJ/mol, 133 kJ/mol e 150 kJ/mol, foram estimadas para as reações de hemicelulose, celulose, lignina e reações secundárias, respectivamente. As ordens de reação para hemicelulose e celulose foram próximas à unidade, enquanto que para lignina e reações secundárias, variaram de 6 a 8. Com isso, concluiu-se que a aplicação do MRIP de quatro reações descreve favoravelmente o processo de decomposição térmica para cada taxa de aquecimento considerada. Como finalização do trabalho, avaliou-se a capacidade preditiva e descritiva, por meio de curvas simuladas da conversão em função da temperatura. O modelo simulado de quatro reações, utilizando os parâmetros cinéticos com três taxas de aquecimento (5°C/min, 7,5°C/min e 10°C/min), mostrou-se preditivo até a temperatura de 360°C para as taxas de aquecimento de 2,5°C e 15°C/min. Complementarmente, aplicando os parâmetros cinéticos médios com taxas de aquecimento de 2,5°C/min a 15°C/min, a capacidade descritiva demonstrou boa concordância entre dados experimentais e simulados para todo o intervalo de temperatura, denotando a habilidade do modelo em descrever o processo de decomposição do endocarpo do fruto de tucumã / Abstract: This work aims to perform a kinetic study of the pyrolysis of tucumã fruit endocarp by using thermogravimetry in nitrogen atmosphere to analyze the thermal decomposition and to estimate the kinetic parameters through global reaction models and independent parallel reaction models. The activation energy, pre-exponential factor, and reaction order were calculated using two sets of data. The first, obtained by Nascimento (2012), applying heating rates from 5°C/min to 20°C/min and mean diameter of 499 µm. The second thermogravimetry data set was obtained in order to evaluate the influence of the particle diameter (from 128,04 µm to 499,55 µm) considering heating rate of 10°C/min, and heating rates (from 2,5°C/min to 15°C/min) with mean diameter of 128,04 µm. Using the first data set, the kinetic parameters were calculated using three isoconversional global reaction models (Ozawa-Flynn-Wall, modified Coats-Redfern, and Friedman), in which were found activation energies between 149 kJ/mol and 159 kJ/mol, pre-exponential factor of about 13 ?1-ns-1 and reaction orders of about 6. The conversion function was defined, corresponding to an nth order reaction mechanism, based on eleven different equation available in the literature. For this data set, the independent parallel reaction model (IPRM) was applied considering reaction for hemicellulose, cellulose, and lignin. Additionally, with the second data set, the IPRM was applied considering three and four reactions, in which an additional reaction was associated to the secondary decomposition reactions. By the application of the three reactions IPRM from the data of Nascimento (2012), close relative deviations were obtained with the data from this work (~4% and ~3%, respectively). However, the application of the four reactions IPRM, relative deviations even lower were obtained (~2%), in which activation energies of about 128 kJ/mol, 198 kJ/mol, 133 kJ/mol, and 150 kJ/mol were estimated for the reactions hemicellulose, cellulose, lignin, and secondary reactions, respectively. The reaction orders for hemicellulose and cellulose were close to unit, while for lignin and secondary reactions varied from 6 to 8. Therewith, it was observed that the application of the four reactions IPRM describes favorably the thermal decomposition process for each heating rate considered. For this work¿s completion, the predictive and descriptive capacity were evaluated using simulated curves of conversion as a function of temperature. The four reactions simulated model using the kinetic parameters with three heating rates (5°C/min, 7,5°C/min, and 10°C/min) was predictive up to 360°C for the heating rates of 2,5°C/min and 15°C/min. Complementarily, using the mean kinetic parameters obtained at heating rates from 2,5°C/min to 15°C/min, the descriptive capacity showed a good agreement between experimental and simulated data for the whole temperature interval, denoting the model¿s ability in describing the decomposition process of tucumã fruit endocarp / Mestrado / Engenharia Química / Mestre em Engenharia Química

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23395号 / エネ博第422号 / 新制||エネ||80(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 河本 晴雄, 教授 亀田 貴之, 教授 杉山 淳司 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

>Magister Scientiae - MSc / Lignocellulose has a complex structure composed mainly of lignin, hemicellulose and cellulose. Several enzymes are needed for the degradation of lignocellulose into simple sugars. Actinomycetes are known to produce laecases which are able to degrade lignin. Laccase activities were detected in actinomycete strains MS26 isolated from soil collected from the Zambian Copperbelt and DFNR17 isolated from soil collected from a New Zealand farm. Morphological .studies showed that the strains produced extensively branched substrate mycelia and aerial hyphae. Micromorphological characteristics were consistent with the assignment of these strains to the genus Streptomyces. Isolates were found to be mesophiles, with growth occurring in a temperature range of 16 and 45°C. Optimal growth occurred at temperatures between 30 and 37°C. Analysis of the 16S rRNA gene sequences of the strains showed that strain MS26 had the highest sequence similarity (99%) to Streptomyces atrovirens strain NRRLB-16357 and Streptomyces viridodiastaticus strain IFO 13106. Strain DFNR17 had the highest 16S rRNA gene sequence similarity (99%) to Streptomyces althioticus strain KCTC9752. The strains shared several physiological and biochemical characteristics with their closest neighbours which, along with 16S rRNA gene sequences analysis, confirmed that the strains were members of the genus Streptomyces. Attempts to identify the laecase genes from these isolates by screening a fosmid library failed. Subsequently isolates were screened by PCR using laccase-like cooper oxidase degenerate primers designed from several Streptomyces strains. A 300 bp amplicon was obtained from both isolates. Phylogenetic analysis was performed and both amplicons from strains MS26 and DFNR17 had the highest similarities with the copper oxidase gene from Streptomyces griseoflavus strain Tu4000. Therefore it is probable that the laecase activity observed for these strains is due to the activity of copper oxidase gene products.

Die Festigkeitseigenschaften des Papiers hängen vom Gehalt und der Verteilung der Hemicellulosen über den Querschnitt der Faserwand ab. Hemicellulosen werden durch verschiedene Bleichverfahren unterschiedlich stark angegriffen und herausgelöst. Durch Untersuchungen an einem Fichtensulfitzellstoff ist es gelungen, die Auswirkungen einzelner Bleichstufen [Peroxidverstärkte Sauerstoffstufe (EOP), Ozonstufe (Z) und Peressigsäurestufe (PAA)] und Bleichsequenzen (EOP-Z-P, EOP-PAA-P) auf Faseroberfläche, Hemicellulosenzusammensetzung und -verteilung sowie auf die optischen und mechanischen Eigenschaften des daraus gebildeten Papiers aufzuzeigen. Um die Verteilung der Hemicellulosen über den Querschnitt der Faser zu beschreiben, wird das Verfahren des chemischen Abschälens verwendet und schrittweise die Faserwand entfernt. Der gebleichte bzw. abgeschälte Zellstoff wird rasterelektronenmikroskopisch untersucht, hydrolysiert und anschließend die Hemicellulosenzusammensetzung quantitativ mittels Hochdruckflüssigkeitschromatographie (HPLC) unter Nutzung eines Flüssigkeitsmassenspektrometers (LCMS) als Detektor bestimmt. Zusätzlich erfolgt die Bestimmung der Papiereigenschaften. Diese Untersuchungen bestätigen, dass die verschiedenen Hemicellulosengehalte nach den Bleichstufen Unterschiede bei den Festigkeitseigenschaften bewirken. Die Untersuchungen zeigen den positiven Effekt der Peressigsäurestufe für die Papierherstellung im direkten Vergleich zur Ozonstufe. Zusätzlich wurde auch der Einfluss des Aufschlusses geprüft. Hierzu wurden die endgebleichten Sulfitzellstoffe mit einem endgebleichten Sulfatzellstoff verglichen. / The mechanical strength of paper pulp depends strongly on the hemicellulose content and the hemicellulose distribution across the cell wall layers. Hemicelluloses get differently attacked and dissolved by different bleaching methods. The investigations with a paper grade sulphite pulp show the influence of the separate bleaching steps [hydrogen peroxide reinforced oxygen stage (EOP), ozone (Z) und peracetic acid (PAA)] and bleaching sequences (EOP-Z-P, EOP-PAA-P) of the fibre surface, hemicellulose content and distribution as well as the optical and mechanical characteristics of paper. To describe the hemicellulose distribution across the cell wall layers a procedure of a precise chemical peeling was used in order to remove stepwise the cell wall. The bleached and peeled pulp was investigated by scanning electronic microscope (SEM) to get more information about the penetration of the bleaching chemicals into the fibre surface. The hemicelluloses were determined by high performance liquid chromatography (HPLC) using a liquid chromatography mass spectrometer (LCMS) after hydrolysing polysaccharides to monosaccharides. In addition to this paper properties were analysed. This research confirms the effect of different hemicellulose compositions of the mechanical strength. The analyses represent the positive effect for paper production of the peracetic acid step in contrast to the ozone step. Additional the influence of the pulping process was determined by a sulphate pulp comparing with the sulphite pulp.

A strategic research area today is development of polymericproducts made from renewable sources. The ways of utilizingrenewable sources studied in this thesis are using 1)prepolymers obtained by steam treatment of wood and 2) monomersobtainable by fermentation of agricultural products. Novel hemicellulose-based hydrogels were prepared by usingprepolymers obtained from steam treatment of spruce.Hemicellulose was first modified with well-defined amounts ofmethacrylic functions. Hydrogels were then prepared by radicalpolymerization with 2-hydroxyethyl methacrylate orpoly(ethylene glycol) dimethacrylate to form hydrogels. Theradical polymerization reaction was carried out in water usinga redox initiator system. The hydrogels were in generalelastic, soft and easily swollen in water. Frequency sweeptests indicated that the hydrogel system displayed prevailingsolid-like behavior. Comparison of the hemicellulose-basedhydrogels with pure poly(2-hydroxyethyl methacrylate)-basedhydrogels showed that it was possible to preparehemicellulose-based hydrogels with properties similar to thoseof pure poly(2-hydroxyethyl methacrylate)-based hydrogels. Polyester-based materials were prepared by using themonomers 1,3- propanediol and succinic acid obtainable byfermentation. α,ω-Dihydroxyterminatedoligomeric polyesters produced by the thermal polycondensationof 1,3-propanediol and succinic acid were chain-extended toobtain sufficiently high molecular weight. Depending on thechain-extension technology adopted, poly(ester carbonate)s orpoly(ester urethane)s were obtained. In the case of poly(estercarbonate)s, the chain-extended products ofα,ω-dihydroxyterminated oligomeric copolyesters werealso produced using 1,3-propanediol/1,4-cyclohexanedimethanol/succinic acid mixtures toimprove thermal and mechanical properties. Segmented poly(esterether carbonate)s fromα,ω-dihydroxyterminated oligo(propylenesuccinate)s and poly(ethylene glycol) were also synthesized toincrease the hydrophilicity. Molecular weights and polydispersity were analyzed by SECfor all materials. Their structures were also identified by NMRspectroscopy (1H NMR and 13C NMR). All characterizations werein agreement with the proposed structures. Thermal parameterswere characterized by DSC. Tensile testing anddynamic-mechanical tests were performed and in additionpreliminary processing trials were carried out in some cases.The results demonstrate the feasibility of using monomersderived from renewable sources to build up new polymericstructures endowed with a variety of physical and mechanicalproperties.

<p>A strategic research area today is development of polymericproducts made from renewable sources. The ways of utilizingrenewable sources studied in this thesis are using 1)prepolymers obtained by steam treatment of wood and 2) monomersobtainable by fermentation of agricultural products.</p><p>Novel hemicellulose-based hydrogels were prepared by usingprepolymers obtained from steam treatment of spruce.Hemicellulose was first modified with well-defined amounts ofmethacrylic functions. Hydrogels were then prepared by radicalpolymerization with 2-hydroxyethyl methacrylate orpoly(ethylene glycol) dimethacrylate to form hydrogels. Theradical polymerization reaction was carried out in water usinga redox initiator system. The hydrogels were in generalelastic, soft and easily swollen in water. Frequency sweeptests indicated that the hydrogel system displayed prevailingsolid-like behavior. Comparison of the hemicellulose-basedhydrogels with pure poly(2-hydroxyethyl methacrylate)-basedhydrogels showed that it was possible to preparehemicellulose-based hydrogels with properties similar to thoseof pure poly(2-hydroxyethyl methacrylate)-based hydrogels.</p><p>Polyester-based materials were prepared by using themonomers 1,3- propanediol and succinic acid obtainable byfermentation. α,ω-Dihydroxyterminatedoligomeric polyesters produced by the thermal polycondensationof 1,3-propanediol and succinic acid were chain-extended toobtain sufficiently high molecular weight. Depending on thechain-extension technology adopted, poly(ester carbonate)s orpoly(ester urethane)s were obtained. In the case of poly(estercarbonate)s, the chain-extended products ofα,ω-dihydroxyterminated oligomeric copolyesters werealso produced using 1,3-propanediol/1,4-cyclohexanedimethanol/succinic acid mixtures toimprove thermal and mechanical properties. Segmented poly(esterether carbonate)s fromα,ω-dihydroxyterminated oligo(propylenesuccinate)s and poly(ethylene glycol) were also synthesized toincrease the hydrophilicity.</p><p>Molecular weights and polydispersity were analyzed by SECfor all materials. Their structures were also identified by NMRspectroscopy (1H NMR and 13C NMR). All characterizations werein agreement with the proposed structures. Thermal parameterswere characterized by DSC. Tensile testing anddynamic-mechanical tests were performed and in additionpreliminary processing trials were carried out in some cases.The results demonstrate the feasibility of using monomersderived from renewable sources to build up new polymericstructures endowed with a variety of physical and mechanicalproperties.</p>