Anionic Polymerization of Styrene in Trimethylamine

Abstract

The polymerization of styrene with metallic sodium as a catalyst in trimethylamine was carried out.
The rate of polymerization was proportional to catalyst concentration and monomer concentration. The overall activation energy was 5.3kcal/mole. The molecular weight of polymers obtained was proportional to monomer concentration, inversely proportional to catalyst concentration and was independent to polymerization temperature. The molecular weight increased with increasing conversion. As the result of measurement of molecular weight distribution, molecular weight distribution wa srather sharp although this reaction has been carried out in heterogeneous system using metallic sodium. For instance, M_w/M_n (molecular weight 200000) was 1.24. The relation of the degree of polymerization vs. monomer concentration and catalyst concentration was represented by the following equation:
and the formation of living polystyrene was suggested.