Viscosity average degree of polymerization

By methylation end-group assay. 1 Number-average degree of polymerization of methylated polysaccharide by id (isothermal distillation) or op (osmotic pressure) methods. c Viscosity-average degree of polymerization. 

Viscosity Determination. Viscosities were measured in 0.5 M cupriethylene-diamine (CED) at 25 °C with a Cannon-Fenske viscometer, size 100 (7). From these measurements, the intrinsic viscosity was determined according to the American Society for Testing and Materials (ASTM) Standard D1795. Values for the viscosity-average degree of polymerization were obtained by multiplying the intrinsic viscosity by 190. 

Effects of emuls If ler, Ini tiator and monomer concentration on the viscosity-average degree of polymerization. 

Weight increase after extractnn expressed in percent of the woght of the starting cellulose. Viscosity-average degree of polymerization. 

Figure 5. Viscosity average degree of polymerization of cellulose heated in air or nitrogen at 150, 170, and 190 °C.

Figure 20-4. Variation in the viscosity-average degree of polymerization with conversion in the bulk polymerization of styrene at 50 C. The same initiator concentrations as in Figure 20-4 were used. (According to data of G. Henrici-Olive and S. Olive.)...

Figure 8-5. Integral mass distribution for a Wesslau distribution. The viscosity-average degree of polymerization (X,), and the mass fraction were measured. The viscosity-average degree of polymerization of the original material with the already known exponent the median value Xjvf, and equation (8-23) and (8-24) were used to calculate the number- and weight-average molecular weights.

Figure 3.18 Stress-strain curve of cellulose nanopaper from wood pulp with different viscosity average degree of polymerization P. ...

Autoacceleration, Glass and Zutty (S) and Burnett and Melville 9) reported an increase in the rate and average degree of polymerization with increasing solution viscosity, heterogeneous conditions and chain coiling for free radical, vinyl polymerizations. Autoacceleration is also called Trommsdorff. (10) effect. 

In the above-mentioned example of the polymer-analogous saponification of poly(vinyl acetate) the reactant and the product differ in their properties, for example, in their solubility however, both compounds have the same average degree of polymerization. The poly(vinyl alcohol) obtained by saponification can, in principle, be esterified back to poly(vinyl acetate) with the original molecular weight the reacetylated polymer then has the same properties as the original material. The viscosity number may be used to check whether in fact any chain scission has occurred during the reaction sequence of saponification and reacetylation (see Example 5-1). 

According to the results acquired through the study of the intrinsic viscosities of the polymer, we have assumed that the reciprocal of the number average degree of polymerization is represented by the relationship ... 

Average Degree of Polymerization of Cellulose by GPC without Viscosity Measurements... 

Figure 17. Relationship between the decrease in the average degree of polymerization and the increase in reducing sugar during the degradation of absorbent cotton by Ex-1, S-I, and F-l, Reaction mixture contained 30 mg absorbent cotton and 10 mL O.IM sodium acetate buffer, pH 4.0, containing enzyme solution. The residual cotton was dissolved in cupram-monium solution and its relative viscosity was measured at 30°C under a nitrogen atmosphere. Final enzyme concentrations 3.0 X 10 2%, 2.2 X 10 2%, and 3.7 X 10 2% for Ex-1, S-l, and F-l, respectively.

A detailed characterization of the physical and chemical properties of (1) chicory inulin, (2) a high-DP fraction of inulin, and (3) fructooligosaccharides (oligofructose) is presented in Table 5.6. A similar assessment for Jerusalem artichoke inulin is not currently available. Due to the lower average degree of polymerization of Jerusalem artichoke inulin, the properties will differ somewhat from those for chicory. As the percent inulin in water increases (Table 5.7), the viscosity increases, which affects the physical properties of the product in which it is an ingredient. 

Finally, the question of the average degree of polymerization (d.p.) of the gluean chains must be considered. Determinations of the d.p. of polysaccharides are usually made by viscosity measurements, but native cellulose, being highly insoluble and often in close association with other cell-wall polysaccharides and lignin, presents special prob-... 

From the solution viscosities number average degrees of polymerization were calculated according to (6) ... 

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