Made available in DSpace on 2014-06-11T19:27:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-06-26Bitstream added on 2014-06-13T18:55:54Z : No. of bitstreams: 1 murakami_ktt_me_araca.pdf: 523881 bytes, checksum: d6fe2b9af367149ccbd1b4521b51f81f (MD5) / Avaliou-se o efeito da utilização de óleo de linhaça na ração de frangos de corte, substituindo o óleo de soja em diferentes períodos, sobre o desempenho, composição de carcaça e características físico-químicas da carne. Foram utilizadas 320 aves, recebendo ração suplementada com óleo de soja ou linhaça, num arranjo fatorial 4x2 (4 períodos crescentes recebendo dieta com óleo de linhaça e dois sexos). O desempenho foi avaliado por pesagens da ração e das aves nos dias 1, 21, 42 e 49, quando as aves foram abatidas. Após o abate, foi avaliado o rendimento de carcaça e a proporção dos principais cortes, vísceras e gordura abdominal. Foram avaliados os teores de lipídeos totais, umidade e colesterol na carne do peito e das coxas com sobrecoxas. A estabilidade da fração lipídica da carne mantida sob congelamento foi avaliada pelo método do ácido 2-tiobarbitúrico (TBA). A textura da carne foi avaliada pela determinação da força de cisalhamento em texturômetro. O óleo de linhaça na ração, de forma geral, prejudicou os parâmetros de desempenho avaliados (P<0,05). As fêmeas apresentaram maior proporção de peito e maior quantidade de gordura abdominal que os machos (p<0,05). As aves alimentadas com ração contendo óleo de linhaça apresentaram menor proporção de gordura abdominal e teores mais baixos de lipídeos totais e colesterol na carne do que aquelas alimentadas exclusivamente com ração contendo óleo de soja (p<0,05). Os resultados observados não permitiram uma avaliação conclusiva quanto à influência do sexo e das fontes de óleo da ração sobre a textura da carne e sua estabilidade à oxidação lipídica. / This work studied the effects of the utilization of linseed oil in broilers feeds as a substituent to soybean oil at different periods on performance and carcass composition of Cobb broilers, well as on the physicalchemical traits of their meat. Three hundred twenty birds were raised with linseed or soybean oil in the feed in a 4x2 factorial arrangement of treatments (4 growing periods receiving the experimental diets and 2 sexes). Performance was evaluated by the weighs of feeds and birds at days 1, 21, 42 and 49 of the experiment. After slaughtering, as the birds were 49 days old, carcass yield and percentages of main cuts, viscera and abdominal fat were quantified. Total lipids, moisture and cholesterol contents in breast and thighs were determined. The stability of the lipidic fraction in frozen meat was determined by the tiobabituric acid (TBA) methodology. Meat shear force was analyzed in a texturometer. In a general sense, linseed oil was harmful to broilers performance (P<0.05). Female broilers had higher breast percentage and more abdominal fat than male broilers (P<0.05). Birds fed linseed oil had less abdominal fat and lower total lipids and cholesterol contents in the meat than those fed soybean oil (P<0.05). Results did not lead to a conclusion about the influence of sex and oil source on meat texture and stability to lipid oxidation.

Made available in DSpace on 2014-12-17T15:01:47Z (GMT). No. of bitstreams: 1 ElisangelaLG.pdf: 1590433 bytes, checksum: 344724364926bacba0bb6a0d130edd0d (MD5) Previous issue date: 2009-05-15 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The aim of the present study was to extract vegetable oil from brown linseed (Linum usitatissimum L.), determine fatty acid levels, the antioxidant capacity of the extracted oil and perform a rapid economic assessment of the SFE process in the manufacture of oil. The experiments were conducted in a test bench extractor capable of operating with carbon dioxide and co-solvents, obeying 23 factorial planning with central point in triplicate, and having process yield as response variable and pressure, temperature and percentage of cosolvent as independent variables. The yield (mass of extracted oil/mass of raw material used) ranged from 2.2% to 28.8%, with the best results obtained at 250 bar and 50?C, using 5% (v/v) ethanol co-solvent. The influence of the variables on extraction kinetics and on the composition of the linseed oil obtained was investigated. The extraction kinetic curves obtained were based on different mathematical models available in the literature. The Mart?nez et al. (2003) model and the Simple Single Plate (SSP) model discussed by Gaspar et al. (2003) represented the experimental data with the lowest mean square errors (MSE). A manufacturing cost of US$17.85/kgoil was estimated for the production of linseed oil using TECANALYSIS software and the Rosa and Meireles method (2005). To establish comparisons with SFE, conventional extraction tests were conducted with a Soxhlet device using petroleum ether. These tests obtained mean yields of 35.2% for an extraction time of 5h. All the oil samples were sterilized and characterized in terms of their composition in fatty acids (FA) using gas chromatography. The main fatty acids detected were: palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2n-6) and &#945;-linolenic (C18:3n-3). The FA contents obtained with Soxhlet dif ered from those obtained with SFE, with higher percentages of saturated and monounsaturated FA with the Soxhlet technique using petroleum ether. With respect to &#945;-linolenic content (main component of linseed oil) in the samples, SFE performed better than Soxhlet extraction, obtaining percentages between 51.18% and 52.71%, whereas with Soxhlet extraction it was 47.84%. The antioxidant activity of the oil was assessed in the &#946;-carotene/linoleic acid system. The percentages of inhibition of the oxidative process reached 22.11% for the SFE oil, but only 6.09% for commercial oil (cold pressing), suggesting that the SFE technique better preserves the phenolic compounds present in the seed, which are likely responsible for the antioxidant nature of the oil. In vitro tests with the sample displaying the best antioxidant response were conducted in rat liver homogenate to investigate the inhibition of spontaneous lipid peroxidation or autooxidation of biological tissue. Linseed oil proved to be more efficient than fish oil (used as standard) in decreasing lipid peroxidation in the liver tissue of Wistar rats, yielding similar results to those obtained with the use of BHT (synthetic antioxidant). Inhibitory capacity may be explained by the presence of phenolic compounds with antioxidant activity in the linseed oil. The results obtained indicate the need for more detailed studies, given the importance of linseed oil as one of the greatest sources of &#969;3 among vegetable oils / O presente trabalho teve como objetivo geral extrair o ?leo vegetal da linha?a (Linum usitatissimum L.) da variedade marrom fazendo uso de di?xido de carbono em condi??es supercr?ticas e de solvente org?nico, avaliar os teores de ?cidos graxos e a capacidade antioxidante do ?leo extra?do e ainda realizar a avalia??o econ?mica r?pida do processo EFS de manufatura do ?leo. Os experimentos foram conduzidos em um extrator de bancada, capaz de operar com di?xido de carbono e co-solventes, obedecendo a um planejamento fatorial 2? com triplicata no ponto central, tendo como vari?vel resposta o rendimento do processo e como vari?veis independentes a press?o, a temperatura e o percentual de co-solvente. Os rendimentos (massa de ?leo extra?do/ massa de mat?ria-prima utilizada) variaram de 2,2 a 28,8%, tendo os melhores resultados sido obtidos a 250 bar e 50?C, com uso do co-solvente etanol a 5% (v/v). A influ?ncia das vari?veis sobre a cin?tica de extra??o e sobre a composi??o do ?leo de linha?a obtido tamb?m foi investigada. As curvas cin?ticas de extra??o obtidas foram modeladas por diferentes modelos matem?ticos dispon?veis na literatura. Os modelos de Mart?nez et al. (2003) e o Simple Single Plate (SSP) de Gaspar et al. (2003) representaram os dados experimentais com os menores erros quadr?ticos m?dios (MSE). O custo de manufatura de 17,85 US$/kg?leo foi estimado para produ??o do ?leo de linha?a utilizando o software TECANALYSIS e a metodologia de Rosa e Meireles (2005). Com o intuito de estabelecer compara??es com a EFS, foram realizados ensaios de extra??o por t?cnica convencional em aparato Soxhlet utilizando ?ter de petr?leo. Estes apresentaram rendimentos m?dios de 35,2 % para um tempo de extra??o de 5h. Todas as amostras de ?leo obtidas foram esterificadas e caracterizadas em termos de sua composi??o em ?cidos graxos (AGs) usando a cromatografia gasosa. Os principais ?cidos graxos detectados foram: palm?tico (C16:0), este?rico (C18:0), ol?ico (C18:1), linol?ico (C18:2n-6) e &#945;-linol?nico (C18:3n-3). Os teores dos AGs obtidos com Soxhlet diferiram daqueles obtidos para a EFS, com percentuais de AGs saturados e monoinsaturados mais elevados para a t?cnica Soxhlet com ?ter de petr?leo. Com rela??o ao teor do ?cido &#945;-linol?nico (componente majorit?rio do ?leo de linha?a) nas amostras, a EFS se mostrou mais vantajosa que a extra??o Soxhlet, apresentando percentuais de 51,18 a 52,71%, enquanto que na extra??o Soxhlet, este foi de 47,84%. A atividade antioxidante do ?leo foi avaliada no sistema de co-oxida??o b-caroteno/?cido linol?ico. Os percentuais de inibi??o do processo oxidativo chegaram a 22,11% para o ?leo da EFS, sendo de apenas 6,09% para o ?leo comercial extra?do a frio, o que sugere que a t?cnica EFS preserva melhor os compostos fen?licos presentes na semente, compostos estes, provavelmente respons?veis pelo car?ter antioxidante do ?leo. Testes in vitro com a amostra de melhor resposta antioxidante foram realizados em homogenato de f?gado de ratos, de forma a investigar a inibi??o da peroxida??o lip?dica espont?nea ou autoxida??o do tecido biol?gico. O ?leo de linha?a se mostrou mais eficiente que o ?leo de peixe (usado como padr?o) na diminui??o da peroxida??o lip?dica do tecido hep?tico dos ratos Wistar, apresentando resultados equivalentes aos obtidos com o uso do BHT (antioxidante sint?tico). A capacidade inibit?ria pode ser atribu?da ? presen?a de compostos fen?licos com atividade antioxidante presentes no ?leo de linha?a. Os resultados obtidos indicam a necessidade de estudos mais aprofundados tendo em vista a import?ncia do ?leo de linha?a como uma das maiores fontes de &#969;3 dentre os ?leos vegetais

Made available in DSpace on 2016-01-26T18:55:32Z (GMT). No. of bitstreams: 1 Marcos_DISSERTACAOCIENCIAANIMAL_29_12.pdf: 1760249 bytes, checksum: 2221031a5e4fc9b1fd527533b56cf561 (MD5) Previous issue date: 2011-12-13 / Keratoconjunctivitis sicca is an ophthalmic disorder that affects the tear. The objective of this study was to evaluate the efficacy of tacrolimus dissolved in almond oil (OA) and linseed (OSL) in the treatment of dry eye syndrome (CCS) induced in rabbits. This study used twenty-five white male rabbits of New Zealand race. The animals were divided into five groups, Group C (control), Group TA (tacrolimus OA), Group TL (OSL tacrolimus), Group A (OA) and Group L (OSL), and were evaluated weekly by Tear Test Schirmer (TLS), Fluorescein Test (TF) and Rose Bengal Test (TRB), monthly by the exfoliative cytology of the ocular surface (CESO), and histopathology at the end of the experiment. The values were significant in TLS with an increase in all treated groups after induction of CCS, featuring improved performance, the group L. In TF, was earlier resolution of corneal ulcers with groups A and L, while in the performance of TRB groups was similar. The TA and TL groups showed less edema and degeneration of the cornea and conjunctiva. Significant increase in the number of goblet cells in all treated groups, especially in groups TA and TL. The evaluation results show that tacrolimus not only with its immunosuppressive effect, but also oily vehicles used for dilution, possibly due to their anti-inflammatory properties, were responsible in improving symptoms of dry eye induced in rabbits / A ceratoconjuntivite seca é um distúrbio oftálmico que afeta a lagrima. O objetivo deste estudo foi avaliar a eficácia do tacrolimus dissolvido em óleo amêndoa (OA) e de semente de linhaça (OSL) no tratamento da ceratoconjuntivite seca (CCS) induzida em coelhos. Neste experimento foram utilizados vinte e cinco coelhos brancos machos da raça Nova Zelândia. Os animais foram alocados em 5 grupos, Grupo C (controle), Grupo TA (tacrolimus em OA), Grupo TL (tacrolimus em OSL), Grupo A (OA) e Grupo L (OSL), sendo avaliados semanalmente pelo Teste de Lágrima de Schirmer (TLS), Teste de Fluoresceína (TF) e Teste de Rosa Bengala (TRB), mensalmente pelo o exame de citologia esfoliativa da superfície ocular (CESO), e análise histopatológica ao final do experimento. Os valores obtidos foram significativo nos TLS com aumento em todos os grupos de tratados após a indução da CCS, apresentando melhor desempenho, o grupo L. No TF, houve resolução mais precoce das úlceras de córnea com os grupos A e L, enquanto no TRB o desempenho dos grupos foi similar. Os grupos TA e TL apresentaram menos edema e degeneração de córnea e conjuntiva. Ocorreu aumento significativo no número de células caliciformes em todos os grupos de tratados, principalmente nos grupos TA e TL. A avaliação dos resultados demonstram que não somente o tacrolimus, com seu efeito imunossupressor, mas também os veículos oleosos utilizados para sua diluição, possivelmente devido às suas propriedades anti-inflamatórias, foram responsáveis na melhora dos sintomas do olho seco induzidos em coelhos.

Made available in DSpace on 2016-07-18T17:53:08Z (GMT). No. of bitstreams: 1 Marcos_DISSERTACAOCIENCIAANIMAL_29_12.pdf: 1760249 bytes, checksum: 2221031a5e4fc9b1fd527533b56cf561 (MD5) Previous issue date: 2011-12-13 / Keratoconjunctivitis sicca is an ophthalmic disorder that affects the tear. The objective of this study was to evaluate the efficacy of tacrolimus dissolved in almond oil (OA) and linseed (OSL) in the treatment of dry eye syndrome (CCS) induced in rabbits. This study used twenty-five white male rabbits of New Zealand race. The animals were divided into five groups, Group C (control), Group TA (tacrolimus OA), Group TL (OSL tacrolimus), Group A (OA) and Group L (OSL), and were evaluated weekly by Tear Test Schirmer (TLS), Fluorescein Test (TF) and Rose Bengal Test (TRB), monthly by the exfoliative cytology of the ocular surface (CESO), and histopathology at the end of the experiment. The values were significant in TLS with an increase in all treated groups after induction of CCS, featuring improved performance, the group L. In TF, was earlier resolution of corneal ulcers with groups A and L, while in the performance of TRB groups was similar. The TA and TL groups showed less edema and degeneration of the cornea and conjunctiva. Significant increase in the number of goblet cells in all treated groups, especially in groups TA and TL. The evaluation results show that tacrolimus not only with its immunosuppressive effect, but also oily vehicles used for dilution, possibly due to their anti-inflammatory properties, were responsible in improving symptoms of dry eye induced in rabbits / A ceratoconjuntivite seca é um distúrbio oftálmico que afeta a lagrima. O objetivo deste estudo foi avaliar a eficácia do tacrolimus dissolvido em óleo amêndoa (OA) e de semente de linhaça (OSL) no tratamento da ceratoconjuntivite seca (CCS) induzida em coelhos. Neste experimento foram utilizados vinte e cinco coelhos brancos machos da raça Nova Zelândia. Os animais foram alocados em 5 grupos, Grupo C (controle), Grupo TA (tacrolimus em OA), Grupo TL (tacrolimus em OSL), Grupo A (OA) e Grupo L (OSL), sendo avaliados semanalmente pelo Teste de Lágrima de Schirmer (TLS), Teste de Fluoresceína (TF) e Teste de Rosa Bengala (TRB), mensalmente pelo o exame de citologia esfoliativa da superfície ocular (CESO), e análise histopatológica ao final do experimento. Os valores obtidos foram significativo nos TLS com aumento em todos os grupos de tratados após a indução da CCS, apresentando melhor desempenho, o grupo L. No TF, houve resolução mais precoce das úlceras de córnea com os grupos A e L, enquanto no TRB o desempenho dos grupos foi similar. Os grupos TA e TL apresentaram menos edema e degeneração de córnea e conjuntiva. Ocorreu aumento significativo no número de células caliciformes em todos os grupos de tratados, principalmente nos grupos TA e TL. A avaliação dos resultados demonstram que não somente o tacrolimus, com seu efeito imunossupressor, mas também os veículos oleosos utilizados para sua diluição, possivelmente devido às suas propriedades anti-inflamatórias, foram responsáveis na melhora dos sintomas do olho seco induzidos em coelhos.

Cette thèse présente l’élaboration de thermodurcissables et de composites biosourcés synthétisés à partir d’huiles végétales époxydées (lin et soja) et d’alcool furfurylique (FA). La première partie de ce travail concerne l’étude de la polymérisation du FA en polyalcool furfurylique (PFA) (i) en solvants protiques polaires, (ii) en combinaison avec le bois et (iii) suivant l’ajout de nouveaux amorceurs. En solvant, les changements de structures observés ont été reliés aux propriétés thermomécaniques. Une autre modification de structure du PFA a été obtenue grâce au 2,5 diméthylfurane. Ce travail a permis d’obtenir une meilleure compréhension de la réactivité du FA au sein du bois et montre que les composites bois/PFA ont une densité et une résistance plus élevées que leurs homologues non modifiés. Enfin, l’amorçage des réactions du FA par l’acide lévulinique ou par le p-toluène sulfonylhydrazine permet de proposer deux nouveaux amorceurs, respectivement biosourcé et « latent ». La seconde partie de ce travail concerne l’élaboration d’une résine époxyde totalement biosourcée et synthétisée à partir d’huiles végétales époxydées. L’huile de lin et de soja ont été chacune copolymérisées avec un acide dicarboxylique. Un premier travail fondamental a consisté à corréler la réactivité de copolymérisation avec les structures des polymères obtenus puis à établir le lien avec les propriétés thermomécaniques. Ensuite, des nanocomposites ont été synthétisés à partir de ces résines époxydes et de sépiolite. Les différentes voies de dispersion et de modification de la sépiolite mises en œuvre conduisent à des niveaux de dispersion différents de la nanocharge au sein de la matrice. / The work presents the elaboration of biobased thermosets and composites synthesized from epoxidized vegetable oils (linseed and soybean) and furfuryl alcohol (FA). A first area of research focused on the study of the polymerisation of FA into polyfurfuryl alcohol (PFA) (i) in protic polar solvents, (ii) in combination with wood and (iii) in the presence of new reaction initiators. In presence of solvents, the observed structural changes have been linked to the thermomechanical properties. Another PFA structure modification was obtained with 2,5 dimethylfuran. This work allowed a better understanding of the reactivity of FA within the wood and shows that the obtained wood/PFA composites have higher density and resistance than their non-modified equivalents. Finally, the initiation of FA polymerization by levulinic acid and p-toluene sulfonylhydrazine, respectively biobased and « latent » initiators has been studied. The second topic of thesis concerns a new type of fully bio-based epoxy resin synthesized from epoxidized vegetable oils. Linseed and soybean oils have both been copolymerized with a dicarboxylic acid as curing agent. A first fundamental work was to correlate the reactivity of copolymerization with the polymer structure and to link them with thermomechanical properties. The obtained thermosets have been used to prepare nanocomposites with sepiolite. Different methods of dispersion and/or modification of sepiolite conduct to diverse morphologies of nanofiller dispersions into the matrix.

Linseed oil has been and is used for vast number of applications, such as in food and paint industry, and wood preservation. It is a good environmental choice, as it originates from renewable sources. Linseed oil is mainly a mixture of triglyceride of fatty acids, both saturated and mono- or polyunsaturated, which allows the oil to oxidize. The oxidation occurs via an auto-oxidation mechanism with the carbon-carbon double bonds and oxygen from the air, reacts to form a polymer. Herein, four different linseed oils (three commercial ones and one industrially available) were analyzed to obtain a better understanding of why different oils provide different protection of wooden materials. This was done by a study of the unoxidized oil, followed by an oxidation time-resolved study of oxidized oil films. The analysis was done by nuclear magnetic resonance, gas chromatography - mass spectrometry and/or inductively coupled plasma atomic emission spectroscopy. This study provided the fatty acid profile of the oils, which were similar for all oils. The unoxidized oils contained some metals ions which probably originate from additives. Aluminum, cobalt, iron, manganese, and zinc was detected in some of the oils at concentrations up to 135 mg/L, but only manganese was detected in all oils and its concentration was much higher than all other metals together. The time-resolved oxidation study had some problems with the solubility of the formed polymers. Several solvents were examined, such as dimethylsulfoxide, alkaline alcohol solutions and toluene, before chloroform-d was chosen as solvent. Though, chloroform-d was not a perfect solvent; it was capable to solve a fraction of the sample, but the fraction decreased with oxidation time. After fifteen days of oxidation, only a few percent of the sample could be dissolved, but for short oxidation times (&lt;48 h) the majority of the samples were dissolved. The oils were analyzed after thirteen different oxidation times. Some structural changes appeared, for example loss of unsaturated protons and some oxidation products arose, such as peroxides and aldyhydes. The diffusion coefficient decreased over the first 3-4 days of oxidation, as expected when the polymerization progressed. After a week of oxidation, the diffusion coefficient increased again, this could possibly be explained by the solubility problem for the large polymer formed. Contrary, at shorter oxidation times this method probably could still be used, as the majority of the sample was dissolved. However, the solubility problem made it impossible to conclude anything about the oxidation rate at longer oxidation times and thus prevented any ranking of the oils. / Linolja har använts och används för många olika tillämpningar, till exempel i mat- och färgindustrin, samt för att bevara trä. Det är klimatmässigt ett bra val, då det kommer från en förnyelsebar källa. Linolja innehåller huvudsakligen en blandning av triglycerider av fettsyror, som både kan vara mättade, enkelomättade eller fleromättade, detta gör att linolja kan oxidera och torka. Oxidationen sker via en auto-oxidation mekanism, med kol-kol dubbelbindningarna och syre från luften som producerar till en polymer. I detta projekt undersöktes fyra olika linoljor (tre kommersiella och en industriell), för att ge en bättre förståelse till varför olika oljor ger olika bra skydd för trämaterial. Detta gjordes genom att undersöka de icke-oxiderade oljorna och sedan göra en tidsstudie på oxiderade oljefilmer. Alla dessa prover analyserades med nuclear magnetic resonance, gas chromatography - mass spectrometry and/or inductively coupled plasma atomic emission spectroscopy. Studien gav resultat på sammansättningen av fettsyror i oljorna, vilken var liknande för alla oljorna. De icke-oxiderade oljorna innehöll ett par metaller, som förmodligen kommer från additiv. Aluminium, kobolt, järn, mangan och zink hittades i några av oljorna i koncentrationer upp till 135 mg/L, men bara mangan var detekterad i alla oljorna och dess koncentration var högre än alla andra metaller tillsammans. Tidsstudien hade problem med lösligheten av proverna. Flertalet lösningsmedel undersöktes, exempelvis dimetylsulfoxid, alkaliska alkohollösningar och toluen, innan kloroform-d valdes som lösningsmedel. Däremot var kloroform-d inte ett perfekt lösningsmedel, den hade förmågan att lösa en del av proverna, men den delen minskade med oxidationstid. Efter femton dagar kunde den bara lösa ett par procent, men efter kortare oxideringstider (&lt;48 h) gick majoriteten av proven att lösa. Oljorna analyserades vid tretton olika oxideringstider. Några strukturella förändringar uppmättes, till exempel minskade mängden dubbelbindningar, och ett par biprodukter från oxideringen detekterades, så som peroxider och aldehyder. Diffusionskonstanterna för oljorna minskade under de första 3-4 dagarna av oxidering, precis som förväntat under polymeriseringen. Efter en vecka av oxidering ökade diffusionskonstanterna igen, det kan förmodligen förklaras av löslighetsproblemen, då diffusionskonstanten är beroende av koncentrationen. Å andra sidan, vid kortare oxideringstider kan denna metod fortfarande användas, eftersom vid denna tidpunkt löste sig fortfarande majoriteten av provet. Dock, löslighetsproblemet gjorde det omöjligt att dra slutsatser kring längre oxideringstider och därmed förhindrades rangordning av oljorna.

Ved består huvudsakligen av tre typer av polymerer, cellulosa, hemicellulosa och lignin. Lignin bildas i naturen genom enzymatiskt initierad oxidativ koppling av tre olika typer av fenylpropan-enheter. Dessa bygger genom olika kol-kol- och kol-syre-bindningar upp en amorf tredimensionell polymer. När kemisk massa tillverkas bryts lignin ner och löses ut i kokluten. Luten innehåller de förbrukade kokkemikalierna och bränns generellt i en sodapanna för att regenerera kemikalierna och producera ånga. Sodapannan är emellertid dyr. Därför har den blivit produktionsbegränsande på många massabruk. Att avlägsna en del av ligninet från avluten vore därför önskvärt och att finna ekonomiskt intressanta produkter baserade på lignin från svartlut är därför ett viktigt forskningsområde . Ett lämpligt område för ligninprodukter vore som tillsatts i oblekt massa. Oblekt massa används till stor del för tillverkning av kraftliner, topp- och bottenskikten på wellpapp. När lådor av wellpapp lagras i containrar som färdas över haven, förändras den relativa luftfuktigheten. Detta gör att lådorna kollapsar lättare än om de skulle ha lagrats vid konstant luftfuktighet, även en hög sådan. Detta är på grund av det så kallade mekanosorptiva- eller accelererade krypfenomenet. Genom tillsatts av våtstyrkemedel till kraftliner eller behandla den med hydrofoba ämnen, finns indikatoner på att mekanosorptiva effekten skulle kunna minska. För att försöka minska den effekten har ett lågmolekylärt kraftlignin, som utvunnits med hjälp av tvärsflödesfiltrering av svartlut och svavelsyrafällning, använts. Genom derivatisering av detta lignin med linolja erhölls ett hydrofobt ligninderivat som uppvisar strukturella likheter med biopolymeren suberin. När detta suberinlika ligninderivat tillsätts till massa verkar det mekanosorptiva krypet minska. När lågmolekylärt lignin används tillsammans med ligninradikalinitiatorerna lackas eller mangan(III) i kraftlinermassa erhålls dessutom en våtstyrka på ca 5% av torrstyrkan. Efter aminering av detta lignin gav en tillsatts till kraftlinermassan en våtstyrka på upp till 10% av torrstyrkan. Det finns indikationer på att det mekanosorptiva krypet samtidigt minskar när dessa behandlingar görs som ger upphov till ökad våtstyrka. / Wood consists mainly of three types of polymers; cellulose, hemi cellulose and lignin. Lignin is formed in nature through enzymatic initiated oxidative coupling of three different kinds of phenyl propane units. These form by various carbon-carbon and carbon-oxygen bonds, an amorphous three-dimensional polymer. As chemical pulp is produced, lignin is degraded and dissolved into pulping liquors. These liquors contain the spent cooking chemicals and are generally burnt in a recovery boiler to regenerate cooking chemicals and produce steam. However, the recovery boiler is expensive. Hence, it has become the bottleneck for production in many pulp mills. Removal of some lignin from the spent cooking liquor would, for that reason, be desired and valuable products based on lignin from cooking liquors are searched for. One suitable area for lignin products would be as additive in unbleached pulp. A major product from unbleached pulp is kraftliner, the top and bottom layers of corrugated board. When boxes of corrugated board are stored in containers travelling overseas the relative humidity is varying. This makes the boxes collapse more easily than if they were stored at constant humidity, even a high one. This is due to the so called mechano-sorptive or accelerated creep phenomenon. By addition of wet strength additive to kraftliner or treating it with hydrophobic compounds there are indications on that the mechano-sorptive effect would decrease. Trying to decrease this effect, low molecular weight kraft lignin has been used. It was obtained by cross-flow filtration of black liquor and precipitation by sulphuric acid. By derivatisation of this lignin by linseed oil, a hydrophobic lignin derivative was obtained, similar in structure to units in the biopolymer suberin. As this suberin-like lignin-derivative was added to pulp the mechano-sorptive creep seemed to be lowered. Furthermore, when the low molecular weight lignin was used together with the lignin radical initiators laccase or manganese(III) in kraftliner pulp, a wet strength of about 5% of dry strength was obtained. An amination treatment of this lignin and addition to kraftliner pulp resulted in a wet strength of up to 10% of dry strength. There are indications of that the mechano-sorptive creep also decreases as these treatments, resulting in increased wet strength, are made. / QC 20101103

Tesis por compendio / [ES] Es evidente cómo el aumento de la concienciación medioambiental respecto al uso de materiales poliméricos de origen petroquímico o plásticos de un único uso ha cambiado por completo el panorama de los materiales poliméricos, desde el punto de vista de su concepción o de su uso. Durante el desarrollo de esta tesis doctoral se ha abarcado varias alternativas con el fin de obtener materiales nuevos, que no tengan solo un bajo impacto ambiental, sino también que posean propiedades competitivas al compararlos con materiales convencionales, además de que su elaboración no conlleve un cambio drástico con respecto a las tecnologías existentes en la actualidad. Es por eso por lo que el objetivo principal de esta tesis doctoral se centra en el desarrollo y caracterización de nuevos materiales con un alto rendimiento medioambiental a partir de matrices termoplásticas como el poli(ácido láctico) (PLA) y matrices termoestables como resinas epoxi con un contenido parcial o total de origen natural. Además del uso de rellenos y fibras de origen natural. / [CA] És evident com l'augment de la conscienciació mediambiental respecte a l'ús de materials polimèrics d'origen petroquímic o plàstics d'un únic ús ha canviat per complet el panorama dels materials polimèrics, des del punt de vista de la seua concepció o del seu ús. Durant el desenvolupament d'aquesta tesi doctoral s'han tingut en compte diverses alternatives amb la finalitat d'obtindre materials nous, que no tinguen només un baix impacte ambiental, sinó també que posseïsquen propietats competitives en comparar-los amb materials convencionals, a més de que la seua elaboració no comporte un canvi dràstic respecte a les tecnologies existents en l'actualitat. És per això, per la qual cosa l'objectiu principal d'aquesta tesi doctoral se centra en el desenvolupament i caracterització de nous materials amb un alt rendiment mediambiental a partir de matrius termoplàstiques com el àcid polilàctic (PLA) i matrius termoestables com a resines epoxi amb un contingut parcial o total d'origen natural. A més de l'ús de reforços i fibres d'origen natural. / [EN] It is remarkable how the increase in environmental awareness regarding the use of polymeric materials of petrochemical origin or single-use plastics has completely changed the scenario of polymeric materials development and use. This doctoral thesis has proposed several alternatives in order to obtain new materials with low environmental impact and competitive properties to conventional materials. In addition to the fact that their elaboration does not entail a drastic change respect to existing technologies. Therefore, the main objective of this doctoral thesis focuses on developing and characterizing new materials with a high environmental performance from thermoplastic matrices such as poly(lactic acid) (PLA) and thermosetting matrices such as epoxy resins with a partial or total content of natural origin. In addition to the use of fillers and fibers of natural origin. / This research work was funded by the Spanish Ministry of Science, Innovation and Universities (MICIU) project numbers RTI2018-097249-B-C21 and MAT2017-84909-C2-2-R. D.L. thanks Universitat Politècnica de València (UPV) for the grant received through the PAID-01-18 program. / Lascano Aimacaña, DS. (2022). Fabricación y caracterización de materiales compuestos de alto rendimiento medioambiental derivados de resinas ecológicas y refuerzos de fibras naturales y estructuras híbridas [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185886 / Compendio