Patent ID: 6906168
Filing Date: 2005-06-14
Classification: C08G,C08J

Abstract:
1. A method for reducing the polydispersivity of a high molecular weight polyetherimide resin comprising: forming a polyetherimide solution using a solvent selected from the group consisting of o-dichlorobenzene and anisole; contacting the polyetherimide solution with an anti-solvent selected from the group consisting of toluene, ketones, acetone, tetrahydrofuran, xylenes, and dioxane wherein the anti-solvent is capable of dissolving low molecular weight species but not the high molecular weight polyetherimide; allowing phase separation to occur to obtain a light phase and a heavy phase; and recovering the desired polyetherimide from the heavy phase, wherein the resulting polyetherimide possessed a polydispersivity ranging from about 1.5 to about 2.5.