Degree of carboxylation

Lignins are most usually employed as various types of sodium lig-nosulfonate and are products of sulfite pulping. (Kraft lignins from the Kraft pulping process are also available.) They are used as dispersants, binders, sequestrants, and emulsifiers. Sodium lignosulfonate product variables include color, MW, and the degree of carboxylation and sulfonation on the lignin backbone. 

The dispersions prepared in the first five experiments listed in Table IV were very stable. The settling data of these samples are plotted in Figure 5. The amount of adsorbed block copolymer in the treatment at room temperature is in about the same range as the pick-up previously obtained with the heat treatment methods, and the total settling times of the best dispersions in Table IV are even somewhat higher than the values previously obtained. At very high degrees of carboxylation (ex-... 

The authors are grateful to W. Reifschneider and R. A. Hickner for their suggestions on the thioglycolic acid addition reaction, to D. L. Schechter for his permission to use his data on fatty acid adsorption, and O. U. Anders for determining the degrees of carboxylation by neutron activation analysis. 

A segment factor / related M to the constant ratio between the carboxyl group and the monomer. With specific reference to pectin, a second factor (/") was later postulated to account for the degree of carboxylation.7 Subsequently, a series of pectins determined to have an anhydrogalacturo-nan content of 68-96% (/" = 0.68-0.96) did not always change the exponent of M. A CMC sample with a 0.75 degree of carboxylation, making /" = 0.25, increased the exponent by 1. 

The effect of the maleic anhydride content in the copolymerization reaction mixture on the degree of carboxylation is illustrated by the data in Table I. Carboxylation of kraft lignin and ligninsulfonates may easily reach levels of 0.7 to 0.8 maleic anhydride units per lignin-building Cg-unit, if the lignin to maleic anhydride ratio in the reactor increases to 2 1. 

Sulfone, carboxylated Single Tg hansparency II had degree of carboxylation 0.43-1.93 Goh et al. (1992d)... 

In practice, the existence of both UCST and LCST has been established for polymer-solvent systems. About 10 years ago, Schmitt discussed UCST, LCST and combined UCST and LCST behavior in blends of poly(methyl methacrylate) with poly(styrene-co-acrylonitrile) (PMMA-PSAN), Ueda and Karasz reported the existence of UCST in chlorinated polyethylene (CPE) blends using DSC, Inoue found that elastomer blends of cis-l,4-polybutadiene and poly(styrene-co-butadiene) exhibit both UCST and LCST behavior and Cong et al. (72) observed that blends of polystyrene and carboxylated poly(2,6-dimethyl-l,4-phenylene oxide) copolymers with a degree of carboxylation between molar fraction 8% and 10% exhibit both UCST and LCST behavior. They used DSC to establish the phase diagram. 

Investigation of the desorption of copper(II) salts of polyacryhc acid showed that at the high saturation degree of carboxyl groups, the salt does not dissolve in water. Therefore, the new phase of unsolved polymer particles appears at the latest stage of adsorption. 

Density of the eured matrix of epoxy resin and GMAEVC with different degrees of carboxyl group substitution was measured using a NaBr solution method in a density measurement column of Techne Inc. [32]. 

Figure 1 DSC scans for mixture of epoxy resin and GMAEVC with different degree of carboxyl group...

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