Description:
<jats:title>Abstract</jats:title><jats:p>Georgiev and Shirota's simplified terminal complex model was applied to the dilatometrically measured initial rate of copolymerization of sytrene (ST) with maleic anhydride (MA) in methyl ethyl ketone (MEK) at 50°C. The rate was maximum at the feed MA mole fractions of 0.752, 0.769, and 0.806 at the total monomer concentrations of 2<jats:italic>M</jats:italic>, 1.5<jats:italic>M</jats:italic>, and 0.5<jats:italic>M</jats:italic>, respectively. Shirota's method gave the following ratios of propagation rate constants: β<jats:sub>A</jats:sub>=<jats:italic>k</jats:italic><jats:sub>AC</jats:sub>/<jats:italic>k</jats:italic><jats:sub>AD</jats:sub> = 8.25 and β<jats:sub>D</jats:sub> = <jats:italic>k</jats:italic><jats:sub>DC</jats:sub>/<jats:italic>k</jats:italic><jats:sub>DA</jats:sub> = 2.70. Georgiev's method gave β<jats:sub>A</jats:sub> = 14, β<jats:sub>D</jats:sub> = 2.7, and α = <jats:italic>k</jats:italic><jats:sub>AD</jats:sub>/<jats:italic>k</jats:italic><jats:sub>DA</jats:sub> = 22. The equilibrium constant of the donor‐acceptor complexation between ST and MA in MEK was measured to be 0.045 dm<jats:sup>3</jats:sup>/mol at room temperature.</jats:p>