You usually have to do a series of experiments - run the copolymerization at different feed ratios of the comonomers, usually stop the polymerization at low conversion, then analyze the resulitng copolymers for incorporation of the co-monomers. That dataset will allow you to calculate the parameters for reactivity ratios.

Dear all, there are many methods to perform such calculations, where the Kelen-Tudos method is the most recommanded. Just seach for it, if it is impossible to get it, please feel free to contact me via email. Regards

Reactivity ratio of two monomer in copolymer can be determined by preparation a different monomers feed ratio under low conversion then chose an element in one of two monomer which this element is characteristic to this monomer, then use fine man rose or Kelen-Tudos method to find the reactivity ratio