Complexation of chitosan with maleic acid copolymers

The complexation of chitosan with alternating copolymers of maleic acid with N-vinylpyrrolidone, ethylene, or styrene is studied. It is found that the process is of a cooperative character and that the binding constants and the Hill parameters are dependent on the nature of a nonionogenic comonomer maleic acid in the synthetic polyanion and on the conditions of complexation. The data of atomic force microscopy and turbidimetric titration confirm the effect of temperature on the conformation of interacting macromolecules and the size of macromolecular aggregates. It is shown that the composition and yield of insoluble interpolyelectrolyte complexes at constant pH are determined by the reactant ratio, the temperature, and the initial concentration of polyelectrolytes.