Cellulose polymerization degree

Recently, we have shown that non-isothermal chemiluminescence measurements for oxidized cellulose provide the same rate constants of cellulose degradation as may be measured from experiments on the decay of polymerization degree determined by viscometry. This may be also taken as indirect evidence that the light emission is somehow linked with the scission of polymer chains [29]. 

The cellulose formula in this equation is simplified by assuming the polymerization degree n = 1. 

Polymerization degree of cellulose (determined by measuring the viscosity of cuprammonium solution) 76 186 254 450 720 1540 2550... 

Effect of the degree of polymerization on the viscosity. It has been made clear by the experiments of many authors that operations leading to the degradation of cellulose prior to nitration contributes to the production of a less viscous nitrocellulose. Moreover, the degree of polymerization of cellulose before nitrating depends upon the origin of the cellulose the type of plant, its age and so on. The properties of the cellulose, such as polymerization degree, are passed on to the nitrocellulose, as already stressed (p. 246), to exert an influence on the viscosity of the product. Hence cotton yields nitrocellulose solutions more viscous than these from wood... 

Figure 11. Effect of Cx enzyme components of T. koningii cellulase on the degree of polymerization of HsPO -swollen cellulose. The degree of polymerization was determined by viscometry after dissolution in Cadoxen...

Hemicellulose (or polyose) is primarily composed of xylan, a branched polymer composed of five-carbon sugar, xylose. Typical polymerization degree of hemicellulose is 50 - 200, which is shorter than the cellulose molecules. The acid hydrolysis of hemicellulose, (C6H10O5)n, produces mainly xylose (C6H10O5), which can be converted to furfural, a chemical feedstock, or can be fermented to ethanol. 

Figure IS- Effect of monomer concentration on the yield of copolymer and apparent number of grafted chains in the pMMA-grafted regenerated cellulose using a quartz tube. Conditions cellulose, 0.3 g HsO, (12 — monomer) mL at 50°C for 6.25 h. Degree of cellulose polymerization 0,95 A, 145 and 0,162.

Polymerization, degree of, of cellulose on heating, 430,435 Polymers, starchlike, 368 Polyoxin C, 116... 

The polymerization degree of native cellulose ranges from 400 to 500 glucose units and the hbers are shorter (2-20 /tm) than those in paper chromatography, preventing the instantaneous spreading of solutes. The specific surface area is about 2 m /g. 

CM-HEC = carboxymethyl-hydroxyethyl cellulose DP = degree of polymerization DS = degree of substitution f = charge density parameter Ap/10 4 m2ft 1 monomoU1, at C = 2 monomol irT3. 

These authors determined crystallinity (and thus S ) from x-ray diffraction data molecular accessibility and surface area of variously milled samples were obtained from iodine adsorption and BET measurements. Degree of cellulose polymerization was determined from viscometry of cadoxen-dlssolved solutions, with the specific viscosity extrapolated to zero concentration to obtained the intrinsic viscosity, [ri], from which in turn the viscosity average molecular weight M was estimated from the Mark-Houwlnk equation ... 

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