Abstract: A process for making ultra-fine particles of a high performance polymer in a yield greater than 90%, which includes dissolving the high performance polymer in an organic solvent capable of dissolving the polymer to form a solution; emulsifying the solution by combining the solution with water and a surfactant to form an emulsion; transferring the emulsion into a receiving water containing a surfactant to remove the organic solvent and form a slurry; and recovering particles of less than 75 microns in diameter in a yield greater than 90%.

Abstract: A process for making ultra-fine particles of a high performance polymer in a yield greater than 90%, which includes dissolving the high performance polymer in an organic solvent capable of dissolving the polymer to form a solution; emulsifying the solution by combining the solution with water and a surfactant to form an emulsion; transferring the emulsion into a receiving water containing a surfactant to remove the organic solvent and form a slurry; and recovering particles of less than 75 microns in diameter in a yield greater than 90%.

Abstract: A method for preparing a polymer-organoclay composite composition comprises combining a solvent and an unexfoliated organoclay to provide a first mixture, wherein the unexfoliated organoclay comprises alternating inorganic silicate layers and organic layers, and has an initial spacing between the silicate layers; exposing the first mixture to an energized condition of a sufficient intensity and duration to increase the initial spacing of the inorganic silicate layers, to provide a second mixture; contacting the second mixture with a polymer composition so that the polymer composition fills at least one region located between at least one pair of silicate layers, wherein the polymer composition is at least partially soluble in the solvent; and removing at least a portion of the solvent from the second mixture, wherein the inorganic silicate layers remain separated by the polymer after removal of the solvent.

Abstract: Disclosed herein is a method for purification of dianhydrides comprising a substantial amount (10000 ppm or more) of at least one metal salt. In one aspect the method is useful for the purification of dianhydrides prepared by the reaction of a halophthalic anhydride with a metal carbonate and may be optionally catalyzed by a phase transfer catalyst. The purification of the dianhydrides may be accomplished by hydrolyzing the dianhydride metal salt mixture directly to a tetraacid with an inorganic acid, followed by separating the impurities from an aqueous phase, and subsequently heating the tetraacid to effect ring closure to form a purified dianhydride having less than 50 parts per million metal halide and lower levels of other residual impurities. In one aspect the method is highly effective in removing phase transfer catalyst impurities such as hexalkylguanidinium halides initially present in the dianhydride undergoing purification.

Abstract: A method for purifying bisimides is provided. In one aspect, purified oxybisphthalimides, intermediates useful in the preparation of polyetherimides are provided. In one embodiment, a first solution containing a bisimide compound, a solvent, and a phase transfer catalyst is contacted with a solid inorganic adsorbent material having a total pore volume of about 0.5 milliliters/gram or greater and a cumulative pore volume distribution of about 20 percent or greater of particles having a pore diameter in a range between about 3 nanometers and about 20 nanometers. The solution containing the bisimide compound is then separated from the solid inorganic adsorbent material to provide a purified bisimide compound which is substantially free of the phase transfer catalyst. The purification technique is especially valuable for preparing high purity oxybisphthalimides, such as 4,4?-oxybis(N-methylphthalimide), which are substantially free of residual phase transfer catalyst.

Abstract: A method for purifying dianhydrides is provided. In one aspect, purified oxybisphthalic anhydrides, intermediates useful in the preparation of polyetherimides are provided. In one embodiment, a first solution containing a dianhydride compound, a solvent, and a phase transfer catalyst is contacted with a solid inorganic adsorbent material having a total pore volume of about 0.5 milliliters/gram or greater and a cumulative pore volume distribution of about 20 percent or greater of particles having a pore diameter in a range between about 3 nanometers and about 20 nanometers. The solution containing the dianhydride compound is then separated from the solid inorganic adsorbent material to provide a purified dianhydride compound which is substantially free of the phase transfer catalyst. The purification technique is especially valuable for preparing high purity oxybisphthalic anhydrides, such as 4,4?-oxybisphthalic anhydride (4,4?-ODPA), which are substantially free of residual phase transfer catalyst.

Abstract: A method for making polyetherimides is provided by reacting a high purity dianhydride with an aromatic diamine under condensation polymerization conditions. The dianhydrides employed are purified by a method comprising contacting a first solution containing a dianhydride compound, a solvent, and a phase transfer catalyst, with a solid inorganic adsorbent material having a total pore volume of about 0.5 milliliters/gram or greater and a cumulative pore volume distribution of about 20 percent or greater of particles having a pore diameter in a range between about 3 nanometers and about 20 nanometers. The solution containing the dianhydride compound is then separated from the solid inorganic adsorbent material to provide a purified dianhydride compound which is substantially free of the phase transfer catalyst. The purified dianhydrides are then condensed with aromatic diamines to provide polyetherimide compositions which are substantially free of residual phase transfer catalyst.

Abstract: A method for purifying oxybisphthalic anhydrides is provided. A first mixture comprising at least one oxybisphthalic anhydride, at least one solvent, and at least one inorganic salt is diluted with a solvent such that the concentration of oxybisphthalic anhydride is less than 25 weight percent. This second mixture is then heated to dissolve the oxybisphthalic anhydride thereby providing a third mixture. The third mixture is then filtered at a temperature above the crystallization temperature of the oxybisphthalic anhydride. The oxybisphthalic anhydride present in the filtrate is then crystallized to provide a purified oxybisphthalic anhydride as a slurry. Also included within the scope of the present invention are a method for preparing oxybisphthalic anhydrides and a method for preparing polyetherimides comprising structural units derived from the oxybisphthalic anhydride purified by the method of the present invention.

Abstract: A process for preparing polyimide resins comprises stirring a diamine and a dianhydride in a solvent to form a slurry; heating the slurry to a temperature sufficient for the diamine and dianhydride to react wherein the temperature is below the melting point of the dianhydride, below the melting point of the diamine, or below the melting points of the dianhydride and diamine; and reacting the diamine and dianhydride to form a polyimide having sufficient molecular weight to precipitate from the solvent.