The present study aimed to investigate the methane yield from anaerobic digestion of a lignocellulosic substrate subjected to different pretreatments. The lignocellulosic forest residues materials were milled and then pretreated with the organic solvent NMMO (N-Methylmorpholine N-oxide) and/or the lignolytic enzymes laccase and versatile peroxidase at a dosage of 60 U g-1 total solids (TS) substrate. The amount of methane produced was studied in a biomethane potential assay with inocula from a thermophilic biogas reactor treating municipal waste. All samples were run in triplicates. Due to the large amount of samples, two biomethane potential assays were conducted: series 10 & 20 and series 30 & 40. The gas production results show that NMMO-treated forest residues yielded 130 NmL CH4 g-1 volatile solids (VS) substrate and the untreated forest residues yielded 95 NmL CH4 g-1 VS substrate for series 10 & 20. For series 30 & 40, both untreated and NMMO-treated forest residues yielded 140 NmL CH4 g-1 VS substrate. NMMO-treatment appears to be favourable and no advantages from the enzyme pretreatment could be seen in terms of gas yield. An analysis of the reaction fluid after the enzymatic treatment showed presence of phenols, an indication of successful lignin hydrolysis. / Studien avsåg att undersöka metanutbytet från anaerob nedbrytning med förbehandlad lignocellulosa som substrat. Lignocellulosamaterialet, i form av skogsavfall, maldes och förbehandlades därefter med det organiska lösningsmedlet NMMO (N-metylmorfolin-N-oxid) och/eller de lignolytiska enzymerna laccase och versatile peroxidas med dosen 60 U g-1 torrsubstanshalt (TS). Mängden producerad metan undersöktes i en biometanpotentialanalys med inocula från en termofil biogasreaktor, som behandlade hushållsavfall. Triplikat av varje prov användes för att öka den statistiska stabiliteten. På grund av det stora antalet prover genomfördes studien i två omgångar: Serie 10 & 20 samt serie 30 & 40. Resultaten visade att det NMMO-behandlade skogsavfallet gav 130 NmL CH4 g-1 organisk substans (VS) och det obehandlade skogsavfallet gav 95 NmL CH4 g-1 VS i serie 10 & 20. Både obehandlat och NMMO- behandlat skogsavfall gav 140 NmL CH4 g-1 VS i serie 30 & 40. Förbehandling med NMMO verkar vara fördelaktig medan enzymbehandling endast resulterade i en smärre ökning av gasproduktionen. En analys av vätskan efter enzymbehandlingen visade förekomst av fenoler, vilket visar på en lyckad ligninnedbrytning.

A STUDY OF LIGNIN DEPOLYMERIZATION BY SELECTIVE CLEAVAGE OF THE Cα-Cβ LINKAGES IN LIGNIN MODEL COMPOUNDS VIA BAEYER-VILLIGER OXIDATION Lignin is amorphous aromatic polymer derived from plants and is a potential source of fuels and bulk chemicals. Herein, we present a survey of reagents for selective stepwise oxidation of lignin model compounds. Specifically, we have targeted the oxidative cleavage of Cα-Cβ bonds as a means to depolymerize lignin and obtain useful aromatic compounds. In this work, we prepared several lignin model compounds that possess structures, characteristic reactivity, and linkages closely related to the parent lignin polymer. We observed that selective oxidation of benzylic hydroxyl groups using TEMPO/O2, followed by Baeyer-Villiger oxidation of the resulting ketones using H2O2, successfully cleaves the Cα-Cβ linkage in the model compounds. This process was also applied to depolymerization of Organosolv lignin. The deconstructed lignin was analyzed by a number of techniques, including ATR-IR, GPC, and 31P NMR of suitably derivatized samples. AN INVESTIGATION OF THE CHANNELING REACTION IN NITROGEN-DOPED MULTIWALLED CARBON NANOTUBES (N-MWCNTS) The reduction of nitrogen-doped multiwalled carbon nanotubes (N-MWCNTs) with Li/NH3 results in deep longitudinal cuts in the nanotubes structure. As the N-MWCNTs are anisotropic, we were able to investigate whether the unzipping process proceeds with equal efficiency from the tip end or from the root (catalyst) end of the N-MWCNT structure. To accomplish this we prepared polymer filled aligned arrays of N-MWCNTs, then exposed one or the other end. Through this approach we were able to shield the sidewalls and either end of the nanotubes from the Li/NH3 solution We have found that when the top end of the N-MWCNTs array was exposed to the reaction mixture, very few nanotubes suffered significant ‘unzipping’. However, when the root (substrate) side of the array is exposed to the reaction mixture, we observe the features characteristic of nanotubes with longitudinal cuts. Our finding provides some insight into the mechanism of the unzipping process, and provides evidence that the unzipping process has a directional preference-unzipping from the root end towards the tip end. And may provide a method for selective functionalization of the interior of tubes and create a new form of nanotube- based porous membrane.

Orientadores: Lucia Helena Innocentini Mei, Nelson Eduardo Duran Caballero / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-13T07:57:38Z (GMT). No. of bitstreams: 1 Camargo_FranciscoAdaode_D.pdf: 5687735 bytes, checksum: 30f309fc3c8612bce1b126f965cd65a9 (MD5) Previous issue date: 2009 / Resumo: A produção de plásticos sintéticos tem aumentado ano após ano, por ser barato, resistente, etc. Mas, os especialistas advertem que o lucro obtido na industrialização e comercialização dos plásticos não pode por em risco o futuro da humanidade. Os fatos demonstram que o planeta já foi prejudicado, principalmente a fauna e a flora marinha. A solução para este problema é o desenvolvimento de materiais biodegradáveis, que garantam um desenvolvimento sustentável, onde o homem e o meio possam conviver sem causar prejuízos entre si. Com este princípio, buscamos neste trabalho o desenvolvimento de blendas biodegradáveis de polímeros naturais, com potencial para substituir alguns dos plásticos convencionais, contribuindo para o binômio produção versus preservação ambiental. A lignina é uma biomacromolécula, assim como o tanino, os quais são disponíveis em grande quantidade no Brasil. O outro componente da blenda, o copolímero de poli(3- hidroxibutirato-co-3-hidroxivalerato) ou PHBV, é uma biomolécula, termoplástico natural, biodegradável e biocompatível. Foi escolhida esta proporção (50:50)% (m/m), esta proporção foi a proporção estudada anteriormente, para a blenda de lignina de bagaço de cana com o PHBV, no aparelho Haake. Os estudos das propriedades mecânicas mostraram boas características de resistência, sendo processada na extrusora dupla rosca e injetada para a confecção dos corpos de prova. Foi estudada a biodegradação das amostras, em meio sólido, por ação dos fungos e bactérias do solo. As caracterizações das blendas (50:50) %, (m/m), ligninas, taninos, PHBV e PHB foram feitas por: Infravermelho com Transformada de Fourier (FT-IR), Calorimetria Diferencial de Varredura (DSC), Análise Dinâmico Mecânica (DMA), Microscopia Eletrônica de Varredura (MEV), Análise Elementar (CHN), Espectroscopia de Fluorescência, Fluorescência de Raios-X e Ressonância Magnética Nuclear de Hidrogênio (RMN- 1H). / Abstract: The production of synthetic plastics has been increasing year after year, for being cheap, resistant, and soon however, the specialists notice that the profit obtained in the industrialization and commercialization of the plastics should not put in risk the Humanity's future. The facts demonstrate that the planet was already harmed, mainly the fauna and the sea flora. The solution for this problem is the development of biodegradable materials to guarantee a sustained development, where the man and the environment have together without causing damages amongst themselves. With this objective, we decided to study in this work the development of biodegradable blends of natural polymer, with potential to substitute some of the conventional plastics, contributing thus the binomial production versus environmental preservation. The lignin is a biomacromolecule, as well as the tannin, theses components are available in great amount in the tropical countries like Brazil. The other component of the blends, the copolymer of poly(3-hydroxybutirate-co-3-hydroxyvalerate) or PHBV, is a natural biomolecule, thermoplastic, biodegradable and biocompatible. It was chosen this proportion (50:50) % (w/w), also this proportion was studied previously in our research group, for the blend of lignin of sugar cane bagasse with PHBV, in the apparatus Haake. The studies of mechanical properties because showed good resistance characteristics. The blends were processed in the twin screw extruders and injected for the making of the test sample. It was studied the biodegradation of the samples, in solid medium, in presence of the fungi and bacteria of the soil. The characterization of blends (50:50%) (w/w), lignins, tannins, PHBV's and PHB's were made by: Fourier Transform Infrared (FT-IR), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Analysis (DMA), Scanning Microscopy Electronic (SEM), Elementary Analysis (CHN), Spectroscopy of Fluorescence, Fluorescence of ray-X and Nuclear Magnetic Resonance of Hydrogen (NMR -1H). / Doutorado / Ciencia e Tecnologia de Materiais / Doutor em Engenharia Química

O desempenho animal pode ser melhorado pelo incremento na digestibilidade dos alimentos. Um dos elementos neste processo é a acurada caracterização da composição química. Objetivando avaliar quatro métodos para determinar o teor de lignina, foram estudadas cinco gramíneas: Brachiaria brizantha cv. Marandú, Brachiaria brizantha cv. Xaraés (MG-5), Panicum maximum cv. Mombaça, Pennisetum purpureum cv. Cameroon e Pennisetum purpureum cv. Napier. As frações fibrosas da parede celular (PC), fibra em detergente neutro (FDN) e fibra em detergente ácido (FDA) aumentaram conforme as plantas amadureceram, refletindo as mudanças na composição dos componentes da parede celular (celulose, hemicelulose e lignina). Os valores de PC foram superiores aos da FDN indicando solubilização da pectina e outros oligossacarídeos da parede celular na solução de detergente neutro. O método LDA apresentou os menores teores de lignina, evidenciando a solubilização de parte da lignina na solução de detergente ácido. Os resultados de LPer foram maiores que os de LDA, que pode ser devido à oxidação da celulose e pectina pelo permanganato de potássio. Os teores de LK foram maiores que os de LDA possivelmente por contaminação protéica, mas, menores que os de LPer. Os teores de LBA foram maiores que os outros três métodos. A digestibilidade acompanhou, de forma inversa, o estádio de maturidade das plantas. A digestibilidade in vitro apresentou forte correlação negativa com os teores de lignina para todos os métodos, menos para LPer. Encontrou-se um valor de relação de 2,23, entre os métodos LDA e LBA, que, ao ser aplicado, nos teores de LDA, resultou em reta similar ao da LBA. Chama a atenção como este valor de 2,23 é muito próximo ao 2,4 utilizado nas equações B2 e C das frações de carboidratos do \"Cornell Net Carbohydrate & Protein System\" e nas equações do National Research Counsil de 1996, para corrigir o teor de lignina. O método LBA é um método fácil e conveniente para determinar a concentração de lignina em forrageiras e uma boa opção para uso rotineiro nas análises de laboratório. / Animal performance can be improved by enhancing feed digestibility. One of the elements for this process is an accurate characterization of feedstuff chemical composition. With the objective of evaluating four methods used today for lignin determination, five grasses were used: Brachiaria brizantha cv. Marandú, Brachiaria brizantha cv. Xaraés (MG-5), Panicum maximum cv. Mombaça, Pennisetum purpureum cv. Cameroon e Pennisetum purpureum cv. Napier, All fibrous fractions, neutral detergent fiber (NDF), acid detergent fiber (ADF) and cell wall (CW), increased as the plants matured, reflecting the changes in the CW composition (cellulose, hemicellulose and lignin). The values obtained for CW were higher than those obtained for NDF, indicating solubilization of pectin and other cell wall oligosaccharides in the neutral detergent solution. The ADL method produced the lowest lignin values, reflecting lignin solubilization by the acid detergent solution. PerL results were higher than those of ADL, possibly due to hemicellulose and pectin oxidation by potassium permanganate. The values for KL were higher than those of ADL, possibly due to protein contamination, but were lower than PerL values. ABL values were the highest among all methods. Digestibility inversely followed plant maturity throughout the study. In vitro dry matter digestibility showed high negative correlation with lignin contents. A 2,23 ratio between ADL and ABL methods was found, which when applied to ADL values, resulted in a curve similar to ABL method curve. It is interesting to note that, this value of 2,23 is very close to the 2,4 used in carbohydrate fractions B2 and C of the \"Cornell Net Carbohydrate & Protein System\", for the correction of lignin content. The ABL method is easy and convenient for total lignin content determination in forages.

Le cadre industriel de ce projet est de trouver une alternative à la résine phénol-formaldéhyde (RFP) et à son durcisseur, utilisée actuellement en pneumatique pour améliorer les performances aussi bien des compositions de caoutchouc que celles des produits semi-finis. Un des aspects essentiels de la pneumatique est d’augmenter la rigidité à faible déformation des pneus sans augmenter l'hystérésis des élastomères durcis chargés de noir de carbone. Ainsi, l'objectif de ce travail de thèse est de proposer un système thermodurcissable alternatif aux résines RFP actuelles. Ce nouveau système doit être riche en carbone renouvelable et doit être chimiquement modifié au moyen de procédés écologiques. La lignine a été choisie comme source de carbone renouvelable. Une étude préliminaire a souligné les potentialités d'une classe de lignines époxy pour l'application visée. Notre approche consiste en la conception de lignines modifiées par des époxy par une méthode originale évitant l'utilisation de l'épichlorhydrine suivie de son durcissement par des agents de réticulation appropriés. Des tests préliminaires avec un composé modèle de lignine ont donné la gamme des composés époxy et les conditions à tester pour la réaction avec la lignine. Les expériences avec la lignine ont alors confirmé le potentiel de l’ester diglycidylique de l’acide 4, 5-époxytetrahydrophthalique, un composé époxy contenant à la fois un groupement cycloaliphatique et deux types de groupements époxy glycidyliques, comme alternative à l'épichlorohydrine pour la préparation de lignines modifiées. Dans les conditions que nous avons définies, la réaction donne des prépolymères de type lignine-époxy sous forme de poudre avec un niveau d’époxydation de 1,2 mol/kg déterminé par spectroscopie FTIR. La série de tests effectuée sur des mélanges de caoutchouc a montré que la nouvelle lignine époxy associée à la p-xylylènediamine peut être mélangée avec succès avec le caoutchouc naturel et peut atteindre les propriétés de notre mix de référence. / The industrial framework of this project is the substitution of phenol formaldehyde resin (RFP) and its methyl donor hardener currently used for improving the performances of rubber compositions of tires or semi-finished products for tires. A critical aspect is the need for an increase of rigidity at low deformation without enhancement of the hysteresis of the cured elastomers filled with carbon black. The specific aim of this PhD work was to propose an alternative thermosetting system to the current RFP resins. This new system should be rich in renewable carbon and chemically modified by environmentally friendly processes. Lignin was chosen as the source of the renewable carbon. A preliminary study emphasized the potentialities of a class of epoxy-modified lignins for the targeted application. The main approach was the design of epoxy modified lignin to be obtained by an original method avoiding the use of epichlorohydrine and to be subsequently cured by appropriate cross-linkers. A preliminary screening with a lignin model compound gave the range of the epoxy compounds and the conditions to be tested for the reaction with lignin. Then various experiments with lignin confirmed the potential of 4, 5-epoxytetrahydrophthalic acid diglycidylester, an epoxy compound containing both one cycloaliphatic and two glycidyl type of epoxy groups, as an alternative for epichlorohydrine for the preparation of modified lignin. In the conditions we have defined, the reaction yielded epoxy lignin-based prepolymers as a powder with epoxy level as high as 1,2 mol/kg determined by FTIR spectroscopy. The series of evaluation campaigns in rubber blends showed that the new epoxy-modified lignin associated with p-xylylenediamine can be successfully mixed with natural rubber and enable to reach the properties of our reference mix.

The depletion of fossil fuels and the need to deal with climate change lead to an increasing interest in renewable resources. Lignocellulosic biomass in general, and agricultural residues in particular, could serve as an excellent starting material for the production of cellulose, basic chemicals, lignin and bioethanol in a biorefinery framework as they are abundant, do not compete with food production and are distributed worldwide. Two factors considerably influence the composition and properties of biorefinery products: biomass feedstock and pretreatment process. Their influence on the separability of raw material into a carbohydrate and lignin fraction as well as the composition and properties of these products are objectives of this study. Hereby, the focus is on lignin, as its structure is particularly dependent on the aforementioned factors complicating its further utilisation. Different agricultural biomass namely barley straw, coconut shell powder, hemp shives, horse manure, maize straw, miscanthus, oat husk, pretreated alfalfa, rape straw, sunflower stalks, tomato stalks and wheat straw were investigated regarding their suitability for lignocellulose separation using alkaline soda pulping. Best separation into a carbohydrate and lignin fraction was achieved for pretreated alfalfa, miscanthus, wheat and barley straw. The purity of the obtained lignin fractions varied in the wide range of 57% klason-lignin content for sunflower stalks and 81% for pretreated alfalfa prior to further purification by dialysis. Lignin fractions were characterised by means of FTIR spectroscopy, elementary analysis, thioacidolysis, size-exclusion-chromatography, thermodesorption, differential scanning calorimetry and different wet chemical methods for determination of functional groups. Lignins could be classified into groups, within which they show similar characteristics: (A) horse manure, rape straw, (B) sunflower stalks, tomato stalks, (C) barley-, maize- and wheat straw and (D) hemp shives, miscanthus. In addition, promising lignin candidates were found for several applications. Thus, by screening different agricultural residues, it is possible to choose a specific raw material, in order to produce lignin with desired properties and functionalities. The effect of the pretreatment process was studied based on wheat straw. It was subjected to conventional alkaline pulping, microwave-assisted alkaline pulping and organosolv pulping using formic acid and hydrogen peroxide. Pulping parameters were varied in order to attain best possible separation into a carbohydrate and lignin fraction. Of the varied parameters the concentration of both sodium hydroxide and formic acid has the highest impact on yield and purity of the products for alkaline and organosolv pulping, respectively. It additionally influences the content of functional groups of the lignin fraction and is hence, an important parameter for lignin customisation for subsequent utilisation. Furthermore, the possibility of reducing pulping time by using microwave-assisted pulping instead of conventional alkaline pulping is promising, as the obtained carbohydrate fraction has a low intrinsic viscosity, which may enhance enzymatic hydrolysis.

The depletion of fossil fuels and the need to deal with climate change lead to an increasing interest in renewable resources. Lignocellulosic biomass in general, and agricultural residues in particular, could serve as an excellent starting material for the production of cellulose, basic chemicals, lignin and bioethanol in a biorefinery framework as they are abundant, do not compete with food production and are distributed worldwide. Two factors considerably influence the composition and properties of biorefinery products: biomass feedstock and pretreatment process. Their influence on the separability of raw material into a carbohydrate and lignin fraction as well as the composition and properties of these products are objectives of this study. Hereby, the focus is on lignin, as its structure is particularly dependent on the aforementioned factors complicating its further utilisation. Different agricultural biomass namely barley straw, coconut shell powder, hemp shives, horse manure, maize straw, miscanthus, oat husk, pretreated alfalfa, rape straw, sunflower stalks, tomato stalks and wheat straw were investigated regarding their suitability for lignocellulose separation using alkaline soda pulping. Best separation into a carbohydrate and lignin fraction was achieved for pretreated alfalfa, miscanthus, wheat and barley straw. The purity of the obtained lignin fractions varied in the wide range of 57% klason-lignin content for sunflower stalks and 81% for pretreated alfalfa prior to further purification by dialysis. Lignin fractions were characterised by means of FTIR spectroscopy, elementary analysis, thioacidolysis, size-exclusion-chromatography, thermodesorption, differential scanning calorimetry and different wet chemical methods for determination of functional groups. Lignins could be classified into groups, within which they show similar characteristics: (A) horse manure, rape straw, (B) sunflower stalks, tomato stalks, (C) barley-, maize- and wheat straw and (D) hemp shives, miscanthus. In addition, promising lignin candidates were found for several applications. Thus, by screening different agricultural residues, it is possible to choose a specific raw material, in order to produce lignin with desired properties and functionalities. The effect of the pretreatment process was studied based on wheat straw. It was subjected to conventional alkaline pulping, microwave-assisted alkaline pulping and organosolv pulping using formic acid and hydrogen peroxide. Pulping parameters were varied in order to attain best possible separation into a carbohydrate and lignin fraction. Of the varied parameters the concentration of both sodium hydroxide and formic acid has the highest impact on yield and purity of the products for alkaline and organosolv pulping, respectively. It additionally influences the content of functional groups of the lignin fraction and is hence, an important parameter for lignin customisation for subsequent utilisation. Furthermore, the possibility of reducing pulping time by using microwave-assisted pulping instead of conventional alkaline pulping is promising, as the obtained carbohydrate fraction has a low intrinsic viscosity, which may enhance enzymatic hydrolysis.

This work presents the mechanisms of free radicals in a model system between fatty acids oxidation process and wood components. The aim is to create a better understanding of new environmentally friendly materials for exterior wood protection. The drying mechanisms of the unsaturated fatty acids with wood model system in the real time were monitored by using RT-IR. This method together with SEC and NMR are enormously powerful spectroscopy techniques to determine the physical and chemical properties of fatty acids-wood during the oxidation process over time. In the first part of this study the focus was in a molecular level on oxidation of methyl linoleate mixed with lignin model compounds (1 and 20 wt%). The effect of lignin structures on unsaturation fatty acids oxidation was determined with 1 wt% lignin model compounds. The interaction, coupling reaction and new structure formations were analyzed through 20 wt% of same lignin compounds mixed with 80 wt% methyl linoleate. The oil oxidation interaction mechanisms were also evaluated by using methyl linoleate, methyl oleate and Linola® on real/natural wood (Norwegian Spruce). In the second part of this work, FT-IR and different NMR methods were used as characterization techniques. The results showed that the oxidative drying process of unsaturated fatty acids was indeed affected by wood constituents. The most hydrophobic part of the wood; lignin, interacted with the oxidation process and some lignin structures inhibited or retarded the reaction. Not only the oil structures were affected but also the lignins were to some extent oxidized as a competing reaction with the oil oxidation. However, a formation of chemicals bonds between the oil and the lignin structures was not observed, i.e. the oils were not immobilized on lignin by covalent bond formation to any significant extent. Further, the focus was on oils in wood using NMR and FTIR demonstrated that highly reactive linoleic acid did react in wood significantly, while it was not immobilized to the same extent. Oleic acid on the other hand reacted more sluggish but the reactive part was immobilized in the wood structure. According to the results, it can be concluded that the structure of the oil is crucial in the overall protective performance of the system. This study indicated that the oxidation pattern of fatty acids behaved differently on wood surface. The wood model compounds minimize the complexity of all elements that exist normally in the natural wood. It can also be concluded that different wood components e.g. end group structures, affect the oil drying process in different ways. The fatty acids pattern will affect not only the structure of the oil dried itself but also the surrounding wood materials. / Detta arbete beskriver friradikalmekanismerna i ett modellsystem mellan fettsyra oxidation och träs beståndsdelar för att skapa bättre förståelse för nya miljövänliga skyddssystem gällande trämaterial som används utomhus. Torkningsmekanismen av omättade fettsyror med trä modellsystem analyserades med hjälp av RT-IR i realtid. Denna metod tillsammans med SEC och NMR spektroskopier understödjer undersökningen av de fysikaliska och kemiska förändringarna av olja och träkomponenter under oxidationsprocessen. I den första delen av denna studie blandades metyl linoleate med ligninmodellföreningar (1 och 20 vikt%). Effekten av olika ligninstrukturer på omättade fettsyrors oxidation, bestämdes med 1vikt% ligninmodellföreningar. Samverkan och kemiska kopplingsreaktioner analyserades med 20 vikt% ligninföreningar genom att dessa kemikalier blandades med metyl linoleate (80 vikt%). Den andra delen av denna studie genomfördes på oljor som oxiderades på trä (gran). Detta genomfördes med hjälp av metyl linoleate, metyl oleat och Linola® på trä. FT-IR och olika NMR karaktäriseringsmetoder användandes i den sista delen av detta arbete. Resultaten visar ett flertal nya faktorer rörande den kemiska och fysikaliska samverkan mellan impregnerande olja och trä som har betydelse för ett optimalt fungerande skydd. Modellstudier mellan torkande oljor och olika ligninkomponenter visar att det sker en kemisk samverkan mellan ligninet och oljorna under oxidationsprocessen. En mycket viktig faktor är att oljan oxideras men att även en del av ligninstrukturerna förändras kemisk under denna process. Slutsatsen är att ligninet påverkar torkhastigheten hos oljan men att oxidationen av oljan också påverkar nedbrytning av ligninet. Studierna visar dock att ingen mätbar mängd olja reagerar kemisk med lignin dvs. oljan fastnar inte genom en kemisk koppling till lignin. NMR studier visar att olika oljor i trä är olika reaktiva, exempelvis reagerar linolja snabbt men merparten av dessa oxidationsreaktioner leder inte till att oljan immobilseras på en molekylär nivå. Mindre reaktiva oljor å andra sidan (exempelvis oljor med hög oljesyrahalt) torkar långsammare men att detta leder till att en större andel immobiliserad olja. Genom att använda trämodellföreningar minimeras komplexiteten av alla element som normalt finns i trä. Från denna studie kan man dra slutsatsen att olika träkomponenter, t.ex. olika kemiska strukturer påverkar olja torkningsprocessen på olika sätt. Fettsyrans kolkedjor påverkar inte bara oljans struktur under sin torkningsmekanism utan även det omgivande trämaterialet. / QC 20110429

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京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18324号 / 農博第2049号 / 新制||農||1021(附属図書館) / 学位論文||H26||N4831(農学部図書室) / 31182 / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 髙野 俊幸, 教授 西尾 嘉之, 教授 梅澤 俊明 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM