Introduction to Cellulose

Cellulose is typically obtained from wood, but is also produced in other plants such as hemp, flax, jute, ramie and cotton. In addition to its production in plant cell walls, it is made by microorganisms such as bacteria. 

There are two forms of cellulose, cellulose I and cellulose II. Cellulose 1 is found in nature and is composed of parallel chains [16]. Cellulose II, the more stable form, is composed of antiparallel chains. There are two distinct allomorphs of cellulose I, 1 and I [17]. The crystal structures of these molecules have been determined [18, 19]. The allomorph I has 1-chain triclinic xmit cell and 1 has 2-chain monoclinic unit [20]. Cellulose I is metastable and is readily converted to 1. The ratio of cellulose I and 1  

Transmission electron microscopy (TEM) of cellulose-producing bacterial cells shows the presence of pores in the outer membrane of these cells. It is believed that bacterial cellulose is produced from uridine diphosphate (UDP)-glucose (its immediate 

There are a number of common techniques that researchers use to characterize bacterial cellulose. Whilst this is by no means a comprehensive list, these techniques do provide a good indication of alterations that may have occurred during the cultivation of the bacteria, as cellulose polymerization and crystallization are closely coupled processes, and changes to the cultivation conditions can change the structure and morphology of the resulting cellulose [35]. 

Nuclear magnetic resonance (NMR) and Fourier transform-infra red (FTIR) spectroscopy have been common techniques used to confirm that the material produced in bacterial culture is bacterial cellulose and to determine the content of the sample. In addition, Yamamoto et at [37] used NMR results to determine that the cellulose content be calculated by the relationship between the FTIR absorbance at peaks 750 and 710 cm The stretching of peaks and additional peaks can indicate the presence of changes or additional materials within the cellulose. 

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M. Sain, and K. Oksman, Introduction to cellulose nanocomposites, in Cellulose nanocomposites Processing, characterization, and properties, K. S. M. Oksman (Ed.), pp. 2. American Chemical Society, Washington, DC. (2006). 

Ciechanska, D., Wesolowska, E., Wawro, D., An Introduction to Cellulosic Fibres , in Handbook of Textile Fibre Structure, Volume II Natural, Regenerated, Inorganic and Specialist Fibres, editors Eichhom, S.J., Heaiie, J.W.S., Jaffe, M., and Kikntani, T., Woodhead Pubhshing Limited, 2009. 

The rapid acceptance of the association theory was accompanied by an equally rapid dropping of the high molecular weight or polymer concept. Olby (31) has stated that three developments made the theory attractive as an explaination for the behavior of polymers. First, he sates, was Alfred Werner s introduction of the concept of two kinds of combining forces—Hauptvalenzen or primary valence forces, and Nebenvalenzen or secondary forces (32). When applied to cellulose, proteins, or rubber, the mole-... 

Bast or Bass is the fibrous inner bark of linden, lime and some milkweed trees. It is used for ropes, mats, peasant shoes(such as Rus"lapti"). The term blast fiber is applied to fibers obtained from the inner bark of flax, hemp, jute, ramie, etc. They contain a considerable amt of cellulose and can be nitrated to NC. However, these substances are more valuable as fabric materials than as sources of NC. Ramie has been used in France for prepn of pure NC Ref J.T.Marsh F.C.Wood, "An Introduction to the Chemistry of Cellulose",Chapman Hall, London( 1945), 1,3 12... 

Both 2 1 chromium and cobalt complex azo dyestuffs have little or no affinity for cellulosic fibres and until the early 1960s their use was restricted to wool and nylon. With the introduction by ICI of their Procion range of fibre-reactive dyes, however, their use was extended to cellulosic fibres on which they give prints having excellent fastness to light and wet treatments. Before that time the development of metal complex dyes for cellulose had followed a similar pattern to that of the development of such dyes for wool but, in this case, the most important metal was copper. Early work in this field has been reviewed by several authors.1 The after-treatment of dyeings on cotton obtained from dyestuffs such as (11) with copper salts was used for many years to improve fastness... 

F.C.Wood, "Introduction to the Chemistry of Cellulose," Chapman Hall, London (1945), 104 3)US Specifics-... 

In contrast to cellulose, which is crystalline, strong, and resistant to hydrolysis, hemicellulose has a random, amorphous structure with little strength. It is easily hydrolyzed by dilute acid or base, but nature provides an arsenal of hemicellulase enzymes for its hydrolysis. Hemicellulases are commercially important because they open the structure of wood for easier bleaching and thus support the introduction of ECF or TCF methods. Many different pentoses are usually present in hemicellulose. Xylose, however, is always the predominating sugar. The pentoses are also present in rings (not shown) that can be five- or six-membered. 

Attempts to get away from paper as a supporting medium, while using some chemically better defined form of cellulose, led to the use of ethanol-treated cellulose powder, packed in columns, and more recently to the introduction of cellulose acetate sheets. 

The introduction of a glutamic acid (E bold), after each RADI 6 repeat was made to allow cleavage by endoproteinase Glu-C, which cleaves C-terminal to glutamate. A cellulose binding domain (CBD) (Table 1) was selected as the affinity tag, as CBDs bind strongly and specifically to cellulose which is a relatively cheap and abundant purification matrix. The main problem encountered was the low level of peptide recovered. Theoretically, 1 g of fusion protein should give 267mg of peptide, but only 10.1 mg of peptide was recovered after RP-HPLC. 

When increasing demands for papermaking fibers in the 19th century led to introduction of cellulose fibers from wood as a more abundant source, it became evident that the wood fibers did not possess all the qualities of cotton fibers. For many years, cotton was considered the first choice for fibers in the manufacture of permanent papers, whereas wood fibers were considered less suitable. It was observed that many papers (particularly book papers) of relatively recent manufacture deteriorated so rapidly as to be useless after no more than a few decades. 

In his introduction to the Lehrbuch, Heuser states objectively Even the methods of treatment adopted by Schwalbe and by Heuser seem to be fundamentally unprofitable, because they do not lead to definite results. These authors have divided the subject along the lines of the various derivatives of cellulose, such as cellulose hydrate, hydrocellulose, oxycellulose, etc. Such discussions are of little value because the substances to which the above names have been applied are not homogeneous chemical individuals, but are mixtures of the most varied degradation products of cellulose and may react very differently under apparently similar conditions. Cross and Bevan have also made the same unfruitful and dangerous mistake of trying to build a system of cellulose chemistry on the basis of such mixtures.. . ... 

Horlick G (1968) Introduction to Fourier transform spectroscopy. Appl Spectrosc 22 617-626 Kawamura L, Higuchi T (1964a) Comparative studies of milled wood lignins from different taxonomical origins by infrared spectroscopy. In Grenoble Symposium 1964, Chimie et biochimie de la lignine, de la cellulose et des hemicelluloses. Lcs Imprimeries Reunies de Chambery, Chambery, 439-456... 

The aim of this paper is to present the different properties of polysaccharide composites obtained by the introduction of cellulose fibres, varying in length and content, into plasticized wheat starch. We have used LDPE-based composites as reference, because without compatibilizer, the LDPE-fibres interactions are usually considered as very poor. To highlight the interactions developed between cellulose and starch, we have compared both kinds of composites. Finally, we have evaluated the post-processing ageing of TPS compared to some other systems. 

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