| Abstract: | The kinetics of the free radical terpolymerization of diethyl maleate (DEM) (M1) with methyl methacrylate (MMA) (M2) and styrene (M3) was investigated at 60°C with AIBN as initiator. The analysis of the dependence of the terpolymer composition on the feed composition was difficult due to the similar chemical and physical properties of diethyl maleate and methyl methacrylate and also by the low content of the former monomer in the terpolymers. Finally, the terpolymer composition could be determined by means of microanalyses of carbon and hydrogen content. The results of these determinations were confirmed by 13C NMR spectroscopy. The initiation rate constant of AIBN was studied at different feed compositions by means of the inhibition method. For the study of the over-all polymerization kinetics of this ternary system it was necessary to take into account the dependence of the termination rate on the feed composition. It was found that not only the viscosity of the solution, but also the properties of the polymer segment next to the radical site have to be considered. Containing only parameters and constants measured independently from terpolymerization, the kinetic equation obtained described satisfactorily the initial over-all rates. |
