Can anyone help me to find out the k & a values (for Mark–Houwink equation) of an alternate co-polymer of maleic acid -sodium salt & di-isobutylene (DIBMA-Na) in 1:1 methanol:0.1N Na2SO4 solution at 25oC or 30oC?
The M-H eqn is Eta (Intrinsic viscosity) = K[M]a . You have to plot intrinsic viscosity of all the copoymers (synthesized using various mole ratio) in solubilizing solvent at particular temperature and separately measure corresponding molecular weight. Plot Eta vs. M. Find K as intercept in Y-axis and slope as a.
Dear Samui,
Thanks for your respond. I have plotted the graph, eta,sp /C vs C & got the Intrinsic viscosity of the sample. The solvent is 1:1 methanol:0.1N Na2SO4 aqueous solution, which I got from available literature. I do not have the K & a values of the same to find the Mv. Can you or someone else help me on finding the same.
Dear All;
I am not sure you will find the "a" and "k" values for such I think special polymer, however if you have different MWs of this block copolymer you can dermine them experimentally. The attached file shed some light on the equation and how to use it. Regards
Dear Abdelkader, thanks for your information. I know it is very specific.
[η]= KMαv
where K and α are two parameters that depend on
the solvent, polymer, and temperature. Values of these
coefficients for several polymers and solvents are presented
in Table in the book chapter attached. More complete tables are reported in different
polymer handbooks [39]. Thus, given an experimental measurement of the intrinsic viscosity in the laboratory,and the values of K and α reported in tables from the
literature, one can obtain the viscosity-average molar mass of a polymer.
find the attached book chapter. which you can find atable of K values fro different solvents.
you can find complete tables in the following handbook.
Brandrup J, Immergut EH, Grulke EA, editors. Polymer
Handbook. 4th ed. New York: Wiley; 1999.
Thnkn you Mr. Ahmed Mahmoud. I will go through the same & revert you back. I have already gone through Brandrup book, but could not find the required one.
FOR rubber polymer how to calculate K and Alpha value . we found that it i soluble in hexane, toluene i need your suggestions
Dear Venkateskumar,
First collect the standard molecular weight samples of the said rubber. Then for every known molecular weight sample put the values in M-H eqn, which is Eta (Intrinsic viscosity) = K[M]a . You have to measure the intrinsic viscosity of all the rubbers in solubilizing in a particular solvent at particular temperature. Now, plot Eta vs. M. Find K as intercept in Y-axis and slope as a for that particular solvent at that particular temperature.
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