Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent in a first extractor for a first time period, at a first extraction temperature and subsequent to the first time period, extracting the aqueous reaction mixture with an organic solvent in a second extractor for a second time period, at a second extraction temperature. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: A method for preparing a poly(phenylene ether) includes feeding air to a continuous flow reactor that contains a reaction mixture including a phenol, a transition metal catalyst, and an organic solvent; and oxidatively polymerizing the reaction mixture at a specified temperature and pressure to form a poly(phenylene ether). The reaction mixture has a residence time in the continuous flow reactor of less than or equal to 30 minutes. Poly(phenylene ether)s prepared by the method and articles including the poly(phenylene ether)s are also described.

Abstract: A method for producing an aromatic dianhydride includes reacting an aromatic diimide with a substituted or unsubstituted phthalic anhydride in an aqueous medium in the presence of an amine exchange catalyst to provide an aqueous reaction mixture including an N-substituted phthalimide, an aromatic tetraacid salt, and at least one of an aromatic triacid salt and an aromatic imide diacid salt. The method further includes removing the phthalimide from the aqueous reaction mixture by extracting the aqueous reaction mixture with an organic solvent in a first extractor for a first time period, at a first extraction temperature and subsequent to the first time period, extracting the aqueous reaction mixture with an organic solvent in a second extractor for a second time period, at a second extraction temperature. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

Abstract: A method for preparing a poly(phenylene ether) includes feeding air to a continuous flow reactor that contains a reaction mixture including a phenol, a transition metal catalyst, and an organic solvent; and oxidatively polymerizing the reaction mixture at a specified temperature and pressure to form a poly(phenylene ether). The reaction mixture has a residence time in the continuous flow reactor of less than or equal to 30 minutes. Poly(phenylene ether)s prepared by the method and articles including the poly(phenylene ether)s are also described.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: A method of preparing a polyetherimide and an improved polyetherimide are disclosed. Low color polyetherimides are disclosed along with process improvements which produce the reduced color of the final product polymers.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: A method of manufacturing polyimide particles includes combining a polyimide solution including a polyimide and an organic solvent with an aqueous solution including water in the presence of an emulsifying surfactant at a shear rate from 1,000 to 3,000 revolutions per minute to form an emulsion. The method further includes removing the organic solvent to form an aqueous polymer dispersion including polyimide particles, and recovering the polyimide particles. The polyimide particles have a spherical morphology and a volume based D10 diameter from 3 to 50 micrometers, a volume based D90 diameter from 3 to 80 micrometers, and a volume based D100 diameter from 3 to 100 micrometers.

Abstract: A method of manufacturing polyimide particles, including: combining a polyimide solution including a polyimide and an organic solvent with an aqueous solution including water in the presence of an emulsifying surfactant at a shear rate from 1,000 to 3,000 revolutions per minute, from 1,000 to 2,500 revolutions per minute, or from 1,500 to less than 2,500 revolutions per minute to form an emulsion; removing the organic solvent to form an aqueous polymer dispersion including polyimide particles; and recovering the polyimide particles, which have a spherical morphology, and a volume based D10 diameter from 3 to 50 micrometers, preferably from 3 to 45 micrometers and a volume based D90 diameter from 3 to 80 micrometers, from 3 to 75 micrometers, or from 3 to 45 micrometers and a volume based D100 diameter from 3 to 100 micrometers, from 3 to 75 micrometers, or from 10 to 75 micrometers.

Abstract: A polyetherimide of improved color and processes for preparing the polyetherimide are disclosed.

Abstract: A method of preparing a polyetherimide and an improved polyetherimide are disclosed. Low color polyetherimides are disclosed along with process improvements which produce the reduced color of the final product polymers.

Abstract: A method of manufacture of a bis(phthalimide) composition includes reacting, in the presence of a solvent and a catalytically active amount of an imidization catalyst selected from quaternary ammonium salts, quaternary phosphonium salts, and combinations thereof, a substituted phthalic anhydride with an organic diamine, wherein conversion to the bis(phthalimide) is 99% complete in less than 6 hours.