The replacement of Br- by trimethylamine for the synthesis of anion exchange adsorbent particles by surface functionalization of polystyrene-divinylbenzene based spherical porous particles was studied experimentally and theoretically. The calculated values of the kinetic parameters indicate that the net rate of the replacement of Br- by trimethylamine is dominated by the kinetic mechanism involving the formation and opening of an epoxide, [GRAPHICS] where P represents the polymeric backbone. The theoretical results obtained from the solution of the equations of the mathematical model that describes the dynamic behavior of the kinetic mechanisms, clearly indicate that the highest concentration of the desired product, [GRAPHICS] on the surface of the pores of the particles, is obtained when the initial concentration of trimethylamine is highest. The equilibrium adsorption of bovine serum albumin (BSA) into the anion exchange adsorbent particles produced in this work was also studied, and the results indicate that the maximum value of the concentration of BSA in the adsorbed phase is a weak function of the concentration of the desired product, [GRAPHICS] on the surface of the pores of the particles.