Mark-Kuhn-Houwink type equation

Determination of D is the first step in studying macromolecular coils by fractal analysis. D is usually estimated by finding the exponents in the Mark-Kuhn-Houwink type equation, which relate the characteristic viscosity [r ], the translational diffusion coefficient Dq, or the rate sedimentation coefficient Sq) with the molecular weight (M) of polymers [3] ... 

It is natural, that the proposed technique, having no specific suppositions, is true not only for biopol uners, but also for other types of macromolecules in solution. In Ref [5] the values for polyarylates number in different solvents are adduced. This allows calculating Devalue for these polymers according to the Eq. (4). Besides, in the same chapter the values of coefficient in Mark-Kuhn-Houwink equations (the Eq. (1)) for the same polymers and approximate equation are adduced [5] ... 

The power dependence of p on defines the strong dependence of Q on Thus, for twofold increase of Q value for PDMDAAC with AZM=3xl0 D reduction from 1.65 up to 1.50 is required at constant flocculator concentration. As it is known through Ref. [1], the exponent a value in Mark-Kuhn-Houwink equation depends on a type of the solvent, used at measurements, therefore macromolecular coil conformation can be changed by the last suitable choice and this way to control its ability to flocculate admixtures. This ability control can be performed by the exponent variation and measurement—as it follows from the Eq. (4), increasing means reduction. 

Nevertheless, the proposed scheme allows to obtain the relationships, similar to the adduced in Figs. 62 and 63, only for one of some polymers type. As it is known [172], the exponent value a in Mark-Kuhn-Houwink equation for polycarbonate (PC) solution in tetrahydrofuran is equal to 0.70 and, hence, let us obtain D=1.76 according to the Eq. (4). If to proceed from the plots of Figs. 62 and 63, this gives the value T 498 K, whereas it is well-known, that for PC the value T is smaller essentially and equal to 423 K [161]. This apparent disparity is due to the fact, that the parameter df gives only general polymer structure... 

---