Studies on Carbamoylation Reactions of Polyethylenimine and Its Low Molecular Weight Analogues with Cyanate Ions

Garbamoylation reaction of ions of polyethylenimine and its low molecular weight analogues, i.e., ethyl-enediamine, triethylenetetramine, and tetraethylenepentamine, with cyanate ions are investigated in the presence of simple-, micelle-, and poly-electrolytes and in their absence. The rate constants are practically independent of the valency of the cations and are much larger than that previously found for the ammonium cyanate reaction. Both of the activation enthalpy and entropy decrease with increasing valency of the cations. Added electrolytes are found to decelerate the reactions. The reactions of poly cations are retarded more strongly by simple cations than by catalyst polycations, whereas those of simple cations are decelerated more effectively by polycations than by simple cations. The kinetic data are discussed thermodynamically in terms of the Bronsted theory and the activity coefficients of the reactant ions. The interaction parameters between reactant electrolyte and added electrolyte are also derived thermodynamically and discussed.