Mark–Houwink equation

https://doi.org/10.1351/goldbook.M03706
The equation describing the dependence of the @I03140@ of a polymer on its @R05271@ (@M04000@) and having the form: \[[\eta] = K\cdot M_{\text{r}}^{a}\] where \([\eta]\) is the intrinsic @V06627@, \(K\) and \(a\) are constants the values of which depend on the nature of the polymer and solvent as well as on temperature and \(M_{\text{r}}\) is usually one of the @R05271@ averages.
Notes:
  1. The use of this equation with the @R05271@ (@M04000@) is recommended, rather than with molar mass (which has the dimension of mass divided by @A00297@), since in the latter case the constant \(K\) assumes awkward and @V06600@ dimensions owing to the fractional and @V06600@ nature of the exponent \(a\).
  2. Kuhn and Sakurada have also made important contributions and their names are sometimes included, as, for example, in the Kuhn–Mark–Houwink–Sakurada equation.
Source:
Purple Book, 1st ed., p. 64 [Terms] [Book]