Thesis (Ph. D.)--Institute of Paper Chemistry, 1963. / Includes bibliographical references (p. 70-73).

A β-1,4-glucan 4-glucanohydrolase or 3.2.1.4. from Trichoderma viride was purified 39-fold over the crude enzyme and completely freed of hydrocellulase, β-1,4-exoglucanase, and aryl-β-D-glucosidase activities by the application of Avicel column adsorption chromatography, alkali swollen cellulose column adsorption chromatography, precipitation with ammonium sulfate, rechromatography on alkali swollen cellulose column, and glass paper electrophoresis at pH 4 in that order. The optimum temperature was 60°C. for the action of this purified enzyme on both amorphous cellulose and CMC for a period of 1 hour incubation. An activation energy of 5.1 Kcal per mole for amorphous cellulose and 6.4 Kcal per mole for CMC between 40° to 60°C. was observed. The optima pH appeared to be 4.2 for amorphous cellulose and 5.0 for CMC. The purified enzyme involved neither activator nor cofactor nor inhibitor in its action, and it was found to be stable at pH 6 to 7 at room temperature for a period of two hours. The sedimentation coefficient of this purified enzyme was 3.5S. It contained no cysteine and only a trace of methionine. From K_m determinations, cellulodextrins with DP above 6 and amorphous cellulose appeared to be the optimum substrates for this purified enzyme, but it did not attack hydrocellulose. A more or less random attack was indicated from the study of mode of action on reduced cellopentaose. Evidence that medium-size chain oligosaccharides might be intermediates in the decomposition of amorphous cellulose by the purified enzyme was obtained. Cellotriose in addition to cellobiose and glucose was found among the principal products from the hydrolysis of both G₅H and amorphous cellulose. The difference in the role of three main cellulase components obtained from T. viride was discussed in connection with the concept of the complete decomposition of cellulose by a multiple enzyme system, and a scheme of the possible mechanism of decomposition of cellulose by the cellulase system of T. viride was proposed. / Ph. D.

All entirely new method had previously been perfected (1) for the determination of molecular weight of cellulose acetate in solution. The applicability of the dielectric dispersion method to other cellulosics was the next step in the development of this new procedure. Ethyl celluloee fractions were refractionated by a fractional precipitation procedure in order to obtain fractions that were homogeneous with respect to chain length. Ethyl acetate and acetone were used in the ratio of three to one (3:1) as solvents, and water acetone in the ratio of ninety-five to five (9515) was employed as a precipitating agent. The homogeneous ethyl cellulose fractions were investigated in a number of solvents – dioxane, benzene, toluene, carbon tetrachloride and n-butyl acetate. This was done in order that the applicability of different solvents could be observed as well as the relation between the viscosity and the critical frequency. The critical frequency is defined as the frequency at which the dispersion is fifty percent completed. 1. Havkine, M. C., Master of Science Thesis, Virginia Polytechnic Institute, 1956. / Ph. D.

Cellulose nitrate does not react with diphenyl or diethyl zinc dissolved in toluene, nor does it react with diethyl tin in liquid ammonia solution. In the latter case the cellulose nitrate is converted to cellulose amine by the ammonolytic effect of the ammonia. Powdered sodium borohydride added to a dilute solution of cellulose nitrate in acetone causes immediate gelation of the ester. The gel is presumed to be formed by the reaction of the hydride with the nitrate groups of cellulose nitrate. Hydrolysis of the complex with water or glacial acetic acid yields a boron and nitrogen free derivative the nature of which is unknown. Cellulose nitrate reacts with ammonia either in the gaseous or liquid state to form cellulose monoamine. The mechanism of the process is the same in all reactions and is independent of the experimental conditions. When the reaction is carried out in the presence of ammono bases such as sodium amide the cellulose amine is considerably degraded and is soluble in water; in all other cases the amine is water insoluble. Cellulose amine in glacial acetic acid solution may be diazotized and coupled with aromatic intermediates to form stable mono-azo derivatives whose properties are independent of the physical properties of the amine. Cellulose amine is deaminated by the action of hypophosphorous acid on the cellulose diazonium salt to a desoxy cellulose containing between one and two per cent amino nitrogen. Several theories are advanced to account for the fact that complete deamination is not realized. The reaction between cellulose nitrate and di-n-butyl amine yields a cellulose di-n-butyl amine of degree of substitution between one and two. The mechanism of the reaction is presumed to be the same as that for the formation of cellulose amine. The cellulose di-n-butyl amine could not be dealkylated. / Ph. D.

M.S.

Due to the increasingly detrimental impacts of the global fossil fuel-driven energy economy, technological solutions that can mitigate the deleterious emissions from fossil fuel conversion or that can lessen societal dependence on fossil fuels are urgently required. The conversion of biomass, a renewable energy feedstock, into energy and fuels that are fungible with those derived from fossil fuels would help supplant some of the global fossil fuel consumption with sustainable energy generation. However, one of the main disadvantages of biomass as an energy feedstock when compared to fossil fuels is its low energy density. The majority of thermochemical biomass conversion technologies therefore focus on converting a low energy density feedstock in biomass to a higher energy density end product. Due to the operating parameters involved in these processes, they are typically accomplished on larger and more centralized scales by skilled operators. Few technologies exist that utilize biomass in a sustainable manner under a distributed energy framework, which would allow energy consumers to use locally available resources and waste material to generate energy. The alkaline thermal treatment of biomass has recently been proposed as a novel method for producing high purity H₂ with suppressed COₓ formation under moderate reaction conditions (i.e., 573 K and ambient pressure). Essentially, biomass, which in this study were the model compounds of glucose and cellulose, is reacted with an alkali metal hydroxide, such as NaOH, in such a molar proportion that all of the carbon and oxygen embodied in the reactants is fixed as an alkali metal carbonate, while all of the elemental hydrogen is released as pure H₂ gas. Thus, fuel cell ready H₂ can be produced from biomass in a single reactor. This technology has great potential for sustainable bioenergy production since it can handle a wide range of feedstocks including biomass and biogenic wastes with high water content. In addition to having the potential to be a distributed energy generation technology, the alkaline thermal treatment of biomass could help meet increasing industrial demand for H₂ in a more sustainable manner, as 96% of current H₂ generation is derived from fossil fuels. The alkaline thermal treatment technology is also relatively unexplored; thus, the effects of parameters such as feedstock type, reaction temperature, heating rate, NaOH:Biomass ratio, method of reactant mixing, flow of steam, and concentration of steam flow, on the gaseous and solid products formed are not fully understood. This study was undertaken to quantify the effects of these non-catalytic variables on the alkaline thermal treatment reaction and to elucidate potential reaction pathways in order to better evaluate the potential of the alkaline thermal treatment technology as a viable biomass conversion technology. In the study of the alkaline thermal treatment of glucose, NaOH did play an important role in suppressing COₓ formation while facilitating H₂ production and promoting CH₄ formation. The non-catalytic alkaline thermal treatment of glucose in the absence of steam flow resulted in a maximum H₂ conversion of about 27% at 523 K with a stoichiometric mixture of NaOH and glucose. The solids analysis confirmed the presence of Na₂CO₃ in the solid product, indicating the inherent carbon management potential of the alkaline thermal treatment process. The addition of steam flow increased conversion to H₂ from 25% to 33%, while decreasing total CH₄ formation 5 fold. After the investigation of the alkaline thermal treatment applied to glucose, cellulose was studied as a feedstock because it is the predominant component of lignocellulosic biomass, the target feedstock source for second generation biofuels. Like in the glucose study, it was found that H₂ and hydrocarbon formation occurred with the addition of NaOH to cellulose under thermal treatment, while the further addition of steam enhanced H₂ production and suppressed hydrocarbon formation. Both the enhancement of H₂ conversion and the suppression of hydrocarbon formation with the addition of steam flow was found to be more significant for cellulose than it was for glucose, with in the cellulose case H₂ conversion doubling from 25% to 48%, and CH₄ formation falling 35 times from the no steam flow case. Also like the glucose study, much of the carbon and oxygen present in the reactants were converted to Na₂CO₃. With the knowledge gained about the effects various reaction parameters had on the alkaline thermal treatment reaction, a study of the reaction pathways of the alkaline thermal treatment of cellulose reaction was undertaken. Compounds formed at intermediate temperatures were identified, tested for gaseous production when reacted with NaOH, and the gas product formation rate trends of these reactions were compared with those trends observed from the alkaline thermal treatment of cellulose reaction. The intermediates identified included sodium carboxylate salts, namely sodium formate, sodium glycolate, and sodium acetate, among others. The reactions of these compounds with NaOH were found to yield H₂ and CH₄, with the gaseous formation rate trends being similar to trends observed for the alkaline thermal treatment reaction for cellulose in certain temperature regions. Particular focus was placed on sodium glycolate, which was an intermediate found in high concentration and that reacted with NaOH to produce both H₂ and CH₄. The formation of Na₂CO₃ at intermediate temperatures was also studied, and the comparison of Na₂CO₃ conversion to H₂ conversion at intermediate temperatures revealed that H₂ and Na₂CO₃ formation do not always occur at the 2:1 H₂:Na₂CO₃ molar ratio implied by the proposed stoichiometry of the alkaline thermal treatment reaction for cellulose. The aforementioned studies were conducted both in the presence and absence of steam flow to study its influence on the reaction. Finally H₂ formation kinetic studies were performed on the alkaline thermal treatment of cellulose system as well as the H₂-producing sodium carboxylate salt reaction systems. Sodium formate and sodium oxalate were found to have better selectivity toward H₂ formation and their reactions were more kinetically favored than sodium glycolate with NaOH. A comparison of the isothermal H₂ kinetics between the cellulose and sodium glycolate systems at higher temperatures, however, revealed that H₂ conversion in the alkaline thermal treatment of cellulose appeared to be limited by the rate of conversion of sodium glycolate. From the results of these studies, recommendations are made for future research directions aimed at improving the alkaline thermal treatment of cellulose reaction.

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Orientador: Claudio Airoldi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-11T15:31:53Z (GMT). No. of bitstreams: 1 SilvaFilho_EdsonCavalcanti_D.pdf: 2613904 bytes, checksum: d11afdfd88c2cca6c7defe5b058e97bd (MD5) Previous issue date: 2008 / Resumo: Dentre agentes usados para clorar a celulose, o cloreto de tionila apresentou melhor resultado com grau de substituição 1,00 na hidroxila primária. Esse intermediário reagiu para incorporar as moléculas 1,2-etilenodiamina, 1,4-butilenodiamina, acetilacetona e 2- aminometilpiridina. Na reação com etilenodiamina foram otimizadas as condições de síntese variando a quantidade e os solventes água ou N-N¿-dimetilformamida, demonstrando que quanto menor o volume de solvente 10,0 cm, maior a incorporação. Na ausência de solvente a quantidade incorporada foi maior, com 3,03±0,01 mmol de grupos pendentes por grama de celulose. Com 1,4-butilenodiamina não houve sucesso na ausência de solvente, porém, com a quantidade mínima de solvente foi 0,66±0,04 mmol g. A acetilacetona não reagiu com a celulose clorada, mas apenas após ser modificada com etilenodiamina e 5,70±0,22 mmol de nitrogênio ficou pendente por grama de celulose, após a formação da base de Schiff em ligações cruzadas. A molécula 2-aminometilpiridina foi incorporada na ausência de solvente, conseguindo 0,10±0,01 mmol g. Esses materiais foram caracterizados e aplicados na remoção de metais divalentes em meio aquoso, com as capacidades de adsorção: a) etilenodiamina 1,32±0,07; 1,91±0,07; 1,08±0,04 e 1,31±0,02, b) etilenodiamina/acetilacetona 2,32±0,06; 1,85±0,02; 1,70±0,04 e 1,65±0,02, c) butilenodiamina 0,32±0,03; 0,29±0,01; 0,26±0,03 e 0,25±0,02 e d) 2-aminometilpiridina 0,100±0,012, 0,093±0,021, 0,074±0,011 e 0,071±0,004 mmol g, para cobre cobalto, níquel e zinco, respectivamente. Foram determinadas as interações cátion-centro básico através de titulação calorimétrica em meio heterogêneo com valores exotérmicos de entalpia. A espontaneidade das reações é expressa pelos valores negativos da energia livre de Gibbs. Com exceção do cobre na celulose modificada com etilenodiamina, do cobalto, níquel e zinco com a celulose modificada com a 2-aminometilpiridina, todos os outros valores de entropia foram positivos, havendo assim um favorecimento entrópico / Abstract: Among the agents used to chlorinate cellulose, thionyl chloride gave better results with a degree of substitution 1.00 on primary hydroxyl group. This intermediate reacted to incorporate the molecules 1,2-ethylenediamine, 1,4-butylenediamine, acetylacetone and 2- aminomethylpyridine. For the reaction with 1,2-ethylenediamine the synthetic conditions was optimized, by varying the amounts and the solvents water or N,N¿-dimethylformamide, demonstrating that the lower the volume of solvent 10 cm, the higher is the incorporation. The absence of solvent yielded the highest amount incorporated, 3.03±0.01 mmol of pendant groups per gram of cellulose. For 1,4-butylenediamine the reaction in absence of solvent failed, however, with a minimum amount of solvent, it gave 0.66±0.04 mmol g. Acetylacetone did not react directly with the chlorinated cellulose, but when the precursor was chemically modified with 1,2-ethylenediamine to give 5.70±0.22 mmol of pendant nitrogen atom per gram of cellulose, Schiff base formation with crosslinking bonds was observed. Aminemethylpyridine was incorporated in the absence of solvent to give 0.10±0.01 mmol g. These materials were characterized and applied for divalent cations removal in aqueous solution. The adsorption capacities gave for: a) 1,2-ethylenediamine 1.32±0.07; 1.91±0.07; 1.08±0.04 and 1.31±0.02, b) 1,2-ethylenediamine/acethylacetone 2.32±0.06; 1.85±0.02; 1.70±0.04 and 1.65±0.02, c) butylenediamine 0.32±0.03; 0.29±0.01; 0.26±0.03 and 0.25±0.02 and d) 2-aminemethylpyridine 0.100±0.012, 0.093±0.021, 0.074±0.011 and 0.071±0.004 mmol g, for copper, cobalt, nickel and zinc, respectively. The cation-basic center interactions determined through calorimetric titration in heterogeneous conditions gave exothermic values, with spontaneity of reactions through all negative free Gibbs energies. With the exception of copper with cellulose chemically modified with 1,2-ethylenediamine, cobalt, nickel and zinc with cellulose modified with 2- aminemethylpyridine, all entropy values were endothermic, to give a favorable entropic conditions / Doutorado / Quimica Inorganica / Doutor em Quimica

Four samples of cellulose acetates having degrees of combined acetic acid between 50.8 - 55.8% were fractionated to obtain sharp fractions or approximately the same degree of polymerization. About 2000 grams starting material of each sample of cellulose acetate were needed to obtain approximately 50 grams or sharp fraction for testing the mechanical properties of their films. Fractionation of the cellulose acetate was from an acetone-water mixture, by addition of n-heptane to precipitate a certain traction. After a series of refractionations, a sharp fraction of each of the four cellulose acetates was obtained. These fractions had different degrees of acetylation but approximately the same degrees of polymerization. These fractions were then dissolved in acetone and cast into films which were conditioned for three days and their mechanical properties were determined in an attempt to determine the effect of degree of acetylation on the mechanical properties. It was found that the degrees of acetylation of the various sharp tractions of cellulose acetates had no appreciable effect on the mechanical properties of their films. It was concluded that the degrees of polymerization of the various fractions were so high that the effect of the degree or acetylation on the mechanical properties could not be detected. The degrees of polymerization of the various samples were determined by the viscosity method using acetone and cupriethylenediamine as the solvents, It was found that the degrees of polymerization of the various samples of cellulose acetates determined by the cupriethylenediamine viscosity method were almost four times greater than the degrees of polymerization of the same samples determined by the acetone viscosity method using constants obtained from the literature. / Ph. D.