Kinetic features of an intraresin reaction

The kinetic features of the intraresin displacement by pendant ammonium acetate groups on chloromethylated polystrene have been investigated as a function of temperature, swelling solvent, and cross-link density. In all cases, intraresin displacement proceeds with a rapid initial rate followed by a very slow stage; the latter represents that fraction of reactants which become ''kinetically isolated''. The free energy of activation for the first stage, under the various swelling conditions used, lies in the range 24.4-26.8 kcal mol/sup -1/, which is similar to that found for analogous homogeneous reactions. The absolute rates measured for the homogeneous and the initial intraresin displacement in dioxane were similar; with n-hexane and toluene as solvents, polymeric rates were considerably slower than those of their homogeneous counterparts. Intraresin displacement was rapid even when a poor swelling solvent (n-hexane) was used. As the rate of intrapolymeric reaction decreased (through a decrease in temperature, increase in cross-link density, or change in solvent), the percent of ''kinetical isolated'' sites increased.