Fikentscher constant

One often makes do with a viscosity measurement at a single concentration (usually 0.5%) to give what is called the inherent viscosity 17)0 = (lni7rei/c)c for this concentration. Fikentscher constants K are also used, particularly in the German literature, to characterize the classic polymers such as poly (styrene) and poly (vinyl chloride). [The K here is not to be confused with the K, defined by Equation (9-151), of the modified Staudinger equation.] K is evaluated from the relative viscosity at relatively high concentrations from tabular data and the equation... 

Hydroxyethyl starch Hydroxyethylsulfoethyl cellulose International Organization for Standardization International Union of Pure and Applied Chemistry Constant, constant of the capillary viscosimeter, constant of the Hoppler viscosimeter, Fikentscher constant Known capillary constant Fuoss constant... 

The intrinsic viscosity [17] (dl/g or ml/g) is an important physico-chemical constant of polymers estimated by extrapolation to an infinite dilution, that is to a zero concentration of the polymer. (For the Fikentscher function k — Eigenviscositat — see p. 278). If the intrinsic viscosity were in fact a measure of the length of the polymer chain molecules, then it would be expected not to vary as a result of changing the solvent. Dobry [59] has determined the viscosities of 0.04% solutions of nitrocellulose (11.4% N) in different solvents and calculated the intrinsic viscosity by means of extrapolation. The results are collected in Table 43. The changes in the... 

It suffices to say that, in whatever direction this field develops, a series of empirical constants, e.g. the characteristic viscosity of Fikentscher or the intrinsic viscosity of Kraemer are already serving a useful purpose in industry as a means of testing solutions used in manufacturing processes. 

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