Patent ID: 7705190

Claim:
A method for making an aromatic polyether sulfone, said method comprising contacting in a reaction mixture the disodium salt of bisphenol A with bis(4-chlorophenyl)sulfone, said contacting being carried out in the presence of a phosphazenium salt having structure I wherein n is an integer from zero to about 10, R 1 and R 2 are independently selected from the group consisting of C 1 -C 20 aliphatic radicals, C 3 -C 20 cycloaliphatic radicals, and C 4 -C 20 aromatic radicals, and wherein said R 1 and R 2 may be linked together form a cyclic structure comprising at least one nitrogen atom, and wherein X is selected from the group consisting of monovalent inorganic anions, monovalent organic anions, polyvalent inorganic anions, polyvalent organic anions, and mixtures thereof, said contacting being carried out at a temperature in a range between about 200° C. and about 250° C., said contacting being carried out in the presence of orthodichlorobenzene.