Cyclic ureas as solvents for poly(aryl ether) synthesis

The synthesis of various poly(aryl ethers) and related small molecule compounds were examined using the cyclic urea 1,3-Dimethyl-3,4,5,6-tetrahydro-2(IH)-pyrimidinone (N,N′-dimethylpropylene urea, DMPU) as the solvent. The results showed that generally higher molecular weight or yields were obtained under less stringent conditions, as compared to other common polymerization solvents. The enhancement was most notable for polymerizations involving aryl fluorides with a lower reactivity than conventionally activated dihalide monomers, e.g. ketones, sulfones. Poly(aryl ethers) displayed excellent solubility in DMPU, which was beneficial in the cases where more rigid heterocyclic-aryl ether polymers are formed. © 1993 Springer-Verlag.