Thesis (Ph.D) - University of Birmingham, Birmingham Carbohydrate and Protein Technology Group, Scool of Chemistry, Faculty of Science, 1996.
|Statement||by Remy Jean-Sebastien Pons.|
Book Description. Completely revised and expanded to reflect the latest advancements in the field, Polysaccharides: Structural Diversity and Functional Versatility, Second Edition outlines fundamental concepts in the structure, function, chemistry, and stability of polysaccharides and reveals new analytical techniques and applications currently impacting the cosmetic, medicinal, chemical, and. In order to obtain information about the crystallinity and polymorphs of cellulose and the occurrence of hemicelluloses in pulp fibers, wood cellulose, bacterial cellulose, cotton linter, viscose and celluloses in different pulps were investigated by solid state 13 C CPMAS NMR spectroscopy. A mixed softwood kraft pulp and a dissolving pulp were. The opening chapter is concerned with the major classifications of polysaccharides, such as homoglycans and diheteroglycans. The succeeding five chapters discuss the occurrence, usage, structural studies, conformation, and derivatives of specific carbohydrate group, including cellulose, plant, algal, bacterial, and fungal polysaccharides. A study was made of polysaccharide distribution in the cell walls of both hardwood fibers and conifer tracheids by means of analysis of fractions obtained through microdissection. Radial sections of about 50 μ in thickness were made through the cambium and the .
Introduction. Dissolving pulps with high alpha cellulose content was obtained by treating the bleached pulp with concentrated sodium hydroxide solution at room temperature (cold refining) or with more diluted sodium hydroxide solution at higher temperature (hot refining) such treatments raised the alpha-cellulose content in the pulp as they dissolved the hemicellulose. Studies of the mobilities of polysaccharides or parts of polysaccharides in a cell-wall preparation may give clues Part of the Methods in Molecular Biology book series () Carbon NMR evidence for cocrystallization of cellulose as a mechanism for hornification of bleached kraft pulp. Cellul 45– CrossRef. The structure of the polysaccharide chains in cellulose in its morphological, supramolecular and molecular level is well described by Krässig (Krässig ), whereas much information on the composition of wood and the wood chemistry containing cellulose can be found in a recent book . Introduction. Cellulose is the most abundant organic compound in the planet and the main structural component of plant cells. It is a linear polysaccharide formed by β-D-glucopyranose units linked by β-1,4-glycosidic covalent bonds (Sjöström ).Native cellulose is formed by two crystalline allomorphs, Iα and Iβ, demonstrated by cross-polarization magic angle spinning (CPMAS) 13 C.
The aim of this work was to study the impact of cellulose depolymerisation on the beating potential and handsheet properties of the portuguese E. globulus kraft pulp. A homogeneous sample of eucalypt wood chips was cooked using different kraft pulping conditions (cooking temperatures and times, and sodium hydroxide and sodium sulphide concentrations) in order to obtain a wide variation for. Soluble saccharides (e.g., polyoses) can be hydrolyzed with diluted TFA, while cellulose, pulp, and wood need treatments with concentrated TFA in homogeneous solution. The presence of lignin impedes the hydrolysis of polysaccharides; thus, especially for wood samples, an intensive treatment with TFA is necessary, and correction values have to. Previous studies have described the formation of strong hydrogen bonds in cellulose systems, especially for cotton linters and sulfite pulps, which result in molecular aggregates. The aggregates exhibit a decreased surface area and pore volume, resulting in decreased pulp reactivity to esterification agents (El-Din and El-Megeid, ). A major step came in with the discovery that celluloses in delignified wood pulp, flax, ramie, and cotton showed practically the same x-ray pattern. Such studies would do much eventually to clarify the structure of cellulose, the mechanical properties of fibers, and the physical basis for the fiber-forming properties of polymeric systems.