Embodiments of the present disclosure provide for an aromatic dianhydride, a method of making an aromatic dianhydride, an aromatic dianhydride-based polyimide, a method of making an aromatic dianhydride-based polyimide, and the like.

A thermal insulator composition and methods of manufacturing made from an admixture of a molding compound, a fire suppressant, and a bonding agent. Water can be added to the admixture to develop the insulator into different phases such as liquid and semi-liquid. The molding compound may be a co-polymer such as an acrylate, polyethylmethacrylate, benzoyl peroxide, titanium dioxide, and one or more iron oxides. The fire suppressant may be an aqueous acrylic acid and potassium co-polymer combination, cross-linked modified polyacrylamides/potassium acrylate or polyacrylamides/sodium acrylate. The bonding agent may be a composition of ethyl methacrylate, hydroxyproptyl methacrylate, clycerol dimethacrylate, triethylene glycol, dimethacrylate, dimethyltolyamine, benzophenone-3, and hydroquinone.

A chemical reactor including: a plurality of heat exchange plates which between them define reaction compartments, in which reactor each heat exchange plate includes two walls between them defining at least one heat exchange space, the respective walls being fixed together by joining regions, and the reactor also comprises at least one injection device for injecting substance into the reaction compartments, said substance-injection device passing through the heat-exchange plates in respective joining regions thereof. Also, a chemical reaction process that can be carried out in this reactor.

A chemical reactor including: a plurality of heat exchange plates which between them define reaction compartments, in which reactor each heat exchange plate includes two walls between them defining at least one heat exchange space, the respective walls being fixed together by joining regions, and the reactor also comprises at least one injection device for injecting substance into the reaction compartments, said substance-injection device passing through the heat-exchange plates in respective joining regions thereof. Also, a chemical reaction process that can be carried out in this reactor.

The invention relates to a catalyst arrangement for preparing phthalic anhydride by gas-phase oxidation of aromatic hydrocarbons, which comprises a reactor having a gas inlet end for a feed gas and a gas outlet end for a product gas and also a first catalyst zone made up of catalyst bodies and at least one second catalyst zone made up of catalyst bodies, where the first catalyst zone is arranged at the gas inlet end and the second catalyst zone is arranged downstream of the first catalyst zone in the gas flow direction and the length of the first catalyst zone in the gas flow direction is less than the length of the second catalyst zone in the gas flow direction, characterized in that the first catalyst zone has a higher gap content compared to the second catalyst zone.

The present invention relates to a process for preparing phthalic anhydride by gas phase oxidation of aromatic hydrocarbons, in which a gas stream comprising at least one aromatic hydrocarbon and molecular oxygen is passed continuously over a thermostatted catalyst and the supply of the at least one aromatic hydrocarbon to the catalyst is temporarily interrupted after putting the catalyst on stream.

The present invention relates to a process for preparing phthalic anhydride by gas phase oxidation of aromatic hydrocarbons, in which a gas stream comprising at least one aromatic hydrocarbon and molecular oxygen is passed continuously over a thermostatted catalyst and the supply of the at least one aromatic hydrocarbon to the catalyst is temporarily interrupted after putting the catalyst on stream.

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 using a sieve tray extraction column. The aromatic tetraacid salt is converted to the corresponding aromatic dianhydride. Aromatic dianhydrides prepared according to the method are also described.

A method for purification of a biphenol dianhydride composition includes contacting the biphenol dianhydride composition with a halogenated solvent to form a solution, and isolating the purified biphenol dianhydride composition from the solution. A method of making a biphenol dianhydride composition including contacting a first solution including a biphenol tetraacid, and at least one of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, nickel ions, titanium ions, chromium ions, magnesium ions, manganese ions, copper ions, phosphorus ions, phosphate ions, sulfate ions, chloride ions, bromide ions, fluoride ions, nitrate ions, and nitrite ions, with a halogenated solvent to provide a second solution, heating the second solution to form the corresponding biphenol dianhydride, and isolating the purified biphenol dianhydride. The biphenol dianhydride is particularly useful for forming poly(etherimides), which can be used in a variety of articles.

A method for purification of a biphenol dianhydride composition includes contacting the biphenol dianhydride composition with a halogenated solvent to form a solution, and isolating the purified biphenol dianhydride composition from the solution. A method of making a biphenol dianhydride composition including contacting a first solution including a biphenol tetraacid, and at least one of sodium ions, potassium ions, calcium ions, zinc ions, aluminum ions, iron ions, nickel ions, titanium ions, chromium ions, magnesium ions, manganese ions, copper ions, phosphorus ions, phosphate ions, sulfate ions, chloride ions, bromide ions, fluoride ions, nitrate ions, and nitrite ions, with a halogenated solvent to provide a second solution, heating the second solution to form the corresponding biphenol dianhydride, and isolating the purified biphenol dianhydride. The biphenol dianhydride is particularly useful for forming poly(etherimides), which can be used in a variety of articles.