Patent ID: 6265521
Filing Date: 2001-07-24
Classification: C08G

Abstract:
A method for preparing a desired aromatic polyether polymer having a predetermined molecular weight which comprises:(A) contacting, at a temperature and sufficiently dry state effective to promote a polymer-producing condensation reaction, at least one alkali metal salt of a dihydroxy-substituted aromatic hydrocarbon with at least one substituted aromatic compound of the formulaZ(A.sup.1 --X.sup.1).sub.2, (I)wherein Z is an activating radical, A.sup.1 is an aromatic radical and X.sup.1 is fluoro, chloro, bromo or nitro, the proportion of said alkali metal salt being less than the total amount calculated to produce said desired polymer, thereby producing an intermediate low molecular weight polymer;(B) determining the molecular weight of said intermediate polymer; and(C) adding a further portion of at least one alkali metal salt, said further portion being calculated to produce said desired polymer and being in the range of between about 0.2 and about 8.0 mole percent of total alkali metal salt, and continuing said condensation reaction to produce said desired polymer.