Modeling of Superacid Catalyzed Step‐Growth Polymerization of Isatin and Biphenyl or Terphenyl Monomers

A mathematical model for the kinetics and molecular weight development of superacid catalyzed step‐growth polymerization of isatin and biphenyl or terphenyl monomers is developed. By considering different reactivities among the several types of polymer molecules present in an otherwise conventional A 2 + B 2 step‐growth polymerization system, ultrahigh molecular weights are predicted by the model for superacid catalyzed polyhydroxyalkylation reactions, a result that remains unclear in the literature since it seems to be in disagreement with the classical A 2 + B 2 theory. Three polymerization systems are addressed in this study: (a) polymerization of isatin and biphenyl, (b) modified isatin and biphenyl, and (c) modified isatin and terphenyl. Overall good agreement between calculated and experimental results of polymerization rate, and evolution of number‐ and weight‐average molecular weights ( M n and M w , respectively) is observed. However, some discrepancies for molar mass dispersity ( Ð ) are observed.