I have measured specific, relative and inherent viscosity of series of polymers I want to report but I want to know do I need to calculate intrinsic viscosity in each case to follow Mark-Houwink equation? Is there any easier method for series calculation of same kind of polymer?
Hello Aniruddha,
If you have access to GPC, it would be an easier method to directly calculate the MW. however, if you want to measure the viscosity average molecular weight using Mark-Houwink equation then you need intrinsic viscosity and better to measure it using capillary viscometer. given you have specific, relative and inherent viscosity, then the double extrapolation plots of specefic viscosity against concentration and inherent viscosity against concentration is plotted by calculating the corresponding specific viscosity and inherent viscosity. The intrinsic viscosity would be the intercept of these graphs.
If you want to measure the molecular weight of polymer you can measure the vicozity and then recalculate it to Mw. I am working with siloxane polymers, so for these polymers I use the special equation for recalculation viscozity to molecular mass. For your polymer the equation may differ. But you also can use chromatography method like SEC/GPC for molecular mass determination.
Dear Iryna, thank you for your answer. But I am here talking about insoluble polymers in normal solvents. Only strong acids like: TFA, H2SO4 can dissolve them. GPC characterization will be impossible for me. Can you please explain me that which equation you use to calculate viscosity from molecular mass.Which kind of viscosity(intrinsic or inherent) you usually determine to calculate the molecular mass.
Dear Amin Shavandi sir, thank you for answering my question. Polymer is very reluctant to soluble in any solvent so GPC technique is not useful in my case. For the series of polymer it is difficult to calculate intrinsic viscosity in each case. So I was looking for some alternative way out.
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