Description:
<jats:title>Abstract</jats:title><jats:p>A general solution is presented for the kinetics of an A–A plus B–C step polymerization. B and C are the same type of functional group but with different reactivities (<jats:italic>k</jats:italic><jats:sub>1</jats:sub> and <jats:italic>k</jats:italic><jats:sub>2</jats:sub>, respectively) toward A groups. The decay of the concentrations of B, C, and A groups and the increase in the degree of polymerization with time are described for various values of the ratio <jats:italic>k</jats:italic><jats:sub>2</jats:sub>/<jats:italic>k</jats:italic><jats:sub>1</jats:sub>.</jats:p>