Cellulose polymer series

Table VI. Michaelis Constants for Cellulose Polymer Series Endo and Exoglucanases of Tricbodertna viride...

L. Segal, in N. M. Bikales and L. Segal, eds.. Cellulose and Cellulose Derivatives, High Polymers Series, Vol. V, Wiley-Interscience, New York, 1971,... 

Fig. 141.—Double logarithmic plot of [77]0 against M for several polymer series polyisobutylene in benzene at 24°C, O polystyrene in cyclohexane at 34°C, cellulose tricaprylate in T-phenylpropyl alcohol at 48 C, Q and...

The more fundamental aspects of fiber constitution and behavior are dealt with in Astbury s Fundamentals of Fibre Structure 27) and Textile Fibres under the X-Rays 28), Hermans Contributions to the Physics of Cellulose Fibres 39), and Physics and Chemistry of Cellulose Fibres (40 Marsh s Textile Science (40 Preston s Fibre Science 59) and the High Polymers series of monographs, three of which are concerned with natural fibers—Volume IV, Natural and Synthetic High Polymers, by Kurt H. Meyer 53), Volume V, Cellulose and Cellulose Derivatives, edited by Emil Ott 56), and Volume VI, Mechanical Behavior of High Polymers, by Turner Alfrey, Jr. 21 ... 

A single cellulosic polymer chain is built up by a series of anhydroglucose units, which are linked together via the beta 1,4 position. Each unit contains three hydroxyl groups, which can be made available for substitution by etherification (Fig. 3). The resulting cellulose-ether within the various substituent types is characterized by... 

The results of sorption experiments on virgin hair are presented in Figures 4 and 5. Though uptake rates and amounts sorbed are lower than those observed by Woodard for PEI 60,000, the pattern shown by these cationic cellulosic polymers is qualitatively similar. Some uptake occurs almost immediately, but it is again evident that sorption continues to increase over a period of minutes, hours, or even days. Within the cellulosic series there is a distinct trend of uptake decreasing as molecular weight increases. 

Emil Ott was universally recognized as the Cellulose Man. He was the one chosen to edit the Interscience book Cellulose and Cellulose Derivatives , Volume V in the High Polymers Series [1]. And he was chosen to talk on Cellulose in the Western Reserve lecture series in 1942 [2] (Fig. 5.1). 

Another activation treatment, suitable for most celluloses (although with great variation of the time required, 1 to 48 h) is polar solvent displacement at room temperature. The polymer is treated with a series of solvents, ending with the one that will be employed in the derivatization step. Thus, cellulose is treated with the following sequence of solvents, before it is dissolved in LiCl/DMAc water, methanol, and DMAc [37,45-48]. This method, however, is both laborious, needs ca. one day for micro crystalline cellulose, and expensive, since 25 mL of water 64 mb of methanol, and 80 mb of DMAc are required to activate one gram of cellulose. Its use may be reserved for special cases, e.g., where cellulose dissolution with almost no degradation is relatively important [49]. 

The results of intrinsic viscosity measurements for four polymer-solvent systems made at the -temperature of each are shown in Fig. 141. The four systems and their -temperatures are polyisobutylene in benzene at 24°C, polystyrene in cyclohexane at 34°C, poly-(di-methylsiloxane) in methyl ethyl ketone at 20°C, and cellulose tricapry-late in 7-phenylpropyl alcohol at 48°C. In each case a series of poly-... 

Through 1959 there existed only one large concentration of polymer chemists in academia (at the Polytechnic Institute of Brooklyn) with several smaller academic centers featuring concentrations in textiles, celluloses and wood, rubber and coatings. Series of short courses, seminars, journals, monograms and textbooks had been established and were to grow through the 60 s to the present. 

The series of degradation steps comprising mineralization is similar, whether the carbon source is a simple sugar (e.g., glucose), a plant polymer (e.g., cellulose), or a pollutant molecule [49,50,62 - 64,72,73]. Each degradation step in the pathway is facilitated by a specific catalyst (i. e., an enzyme) made by the degrading cell. Enzymes are found mostly within a cell (i. e., internal enzymes),... 

It has been stated mat me reactivity of the wood cell wall polymers to acetic anhydride decreases in me order lignin > hemicelluloses > cellulose, both within me wood cell wall (Rowell, 1982) and with me isolated polymers (Callow, 1951 Rowell etal., 1994 Efanov, 2001). A comprehensive series of NMR studies has been performed investigating me substitution of me cell wall polymeric OH groups at various WPGs (Ohkoshi and Kato, 1992, 1993, 1997a,b). These have shown that not all of me lignin OH groups are... 

In contrast, other natural polymers, such as natural rubber (NR), cellulose, and most synthetic polymers, consist of mixtures of many members of a homologous series. These homologues contain varying numbers of units and thus have different molecular weights, and hence the polymers are said to be polydisperse or polymolecular. 

At this point it seems of interest to include a graph obtained on a quite different polymer, viz. cellulose tricarbanilate. Results from a series of ten sharp fractions of this polymer will be discussed in Chapter 5 in connection with the limits of validity of the present theory. In Fig. 3.5 a double logarithmic plot of FR vs. is given for a molecular weight of 720000. This figure refers to a 0.1 wt. per cent solution in benzophenone. It appears that the temperature reduction is perfect. Moreover, the JeR-value for fiN smaller than one is very close to the JeR value obtained from Figure 3.1 for anionic polystyrenes in bromo-benzene. As in the case of Fig. 3.1, pN is calculated from zero shear viscosity. The correspondence of Figs. 3.1 and 3.5 shows that also the molecules of cellulose tricarbanilate behave like flexible linear chain molecules. For more details on this subject reference is made to Chapter 5. 

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