A method for manufacturing a poly(imide) prepolymer powder includes combining a bisanhydride powder or organic diamine and a solvent comprising an alcohol, a water-soluble ketone or water to form a mixture, adding an organic diamine or bisanhydride powder to the mixture to form a poly(imide) prepolymer, and removing the solvent to provide the poly(imide) prepolymer powder. A method for manufacturing a poly(imide) prepolymer varnish includes combining a bisanhydride powder or organic diamine and a solvent comprising an alcohol, a water-soluble ketone or water to form a mixture, and adding an organic diamine or bisanhydride powder to the mixture to form a poly(imide) prepolymer. The method of manufacturing the varnish further includes at least one of adding an effective amount of a secondary or tertiary amine to solubilize the poly(imide) prepolymer powder, heating the mixture to a temperature effective to provide the varnish, or agitating the mixture to provide the varnish. The poly(imide) prepolymer powder and varnish can have a residual organic diamine content of less than or equal to 1000 ppm. A poly(imide) polymer prepared from the prepolymer powder or varnish is also disclosed.

Provided are a polyamic acid solution that can be formed into a film without peeling even when the film is thick and can be stably stored at room temperature, and a laminate that can be suitably used for production of a flexible device. In the alkoxysilane-modified polyamic acid solution according to the present invention, an additive amount of an alkoxysilane compound that contains an amino group is more than 0.050 parts by weight and less than 0.100 parts by weight.

A method for producing a polyimide resin powder, which involves reacting a tetracarboxylic acid component containing a tetracarboxylic dianhydride and a diamine component containing an aliphatic diamine in the presence of a solvent containing an alkylene glycol solvent of formula (1). In formula (1), Ra.sub.1 represents a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms, Ra.sub.2 represents a linear alkylene group having from 2 to 6 carbon atoms, and n represents an integer of 1 to 3. The reacting produces a solution containing a polyimide resin precursor. This solution is then heated at an average heating rate of 0.5 to 8? C./min in a temperature range of 70 to 130? C. to imidize the polyimide resin precursor to produce the polyimide resin powder in the solution with a solid content concentration of 15 to 25% by mass.

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The present disclosure relates to a polyimide-based block copolymer film. The polyimide-based block copolymer film according to the present disclosure exhibits excellent an ultraviolet shielding property to be suitably used for substrates for displays, protective films for displays, touch panels, and the like.

A polyimide-forming composition includes a particulate polyimide precursor composition having an average particle size of 0.1 to 100 micrometers wherein the polyimide precursor composition comprises a substituted or unsubstituted C.sub.4-40 bisanhydride, and a substituted or unsubstituted divalent C.sub.1-20 diamine; an aqueous carrier; and a surfactant. A method of manufacturing an article including a polyimide includes the steps of forming a preform comprising the polyimide-forming composition; and heating the preform at a temperature and for a period of time effective to imidize the polyimide precursor composition and form the polyimide. An article prepared by the method, and a layer or coating including a polyimide and a surfactant are also described.

A method for producing an aromatic bisimide includes reacting a dialkali metal salt of a dihydroxy aromatic compound with a reactive substituted phthalimide under conditions effective to form a product mixture, introducing the product mixture to a liquid-liquid extraction column including an aqueous alkali metal hydroxide solution, and recovering from the liquid-liquid extraction column a purified aromatic bisimide having less than 500 ppm of residual dialkali metal salt of the dihydroxy aromatic compound, the corresponding dihydroxy aromatic compound, the corresponding mono-substituted salt of the dihydroxy aromatic compound, or a combination including at least one of the foregoing. A method for the manufacture of a polyetherimide from an aromatic bisimide prepared by the above method is also disclosed. A polyetherimide having less than 100 ppb of residual bisphenol A and an article made therefrom are also described.

A treatment fluid and a plurality of proppant particles, which comprise a cross-linked polyimide aerogel, are provided for use in the fracking of subterranean formations. The cross-linked polyimide aerogel can have a porosity above about 80% and a compressive strength in the range from about 10,000 psi to about 50,000 psi. The cross-linked polyimide aerogel can be derived by cross-linking oligomers, wherein each oligomer comprises a base unit of one or more dianhydrides and one or more diamines.

Novel aromatic polyimides are disclosed with sufficient physical properties to be useful in 3D printing.

A fast-response thermoplastic shape-memory polyimide and a preparation method thereof, related to a polyimide and a preparation method thereof. The present invention aims to solve the problem in high-temperature conditions of slow shape recovery poor stability, and poor mechanical properties of a shape-memory polymer prepared by utilizing an existing method. The structural formula of the polyamide of the present invention is as represented by formula (I). The preparation method is: 1. preparation of a diamine solution; 2. preparation of an anhydride-terminated high molecular weight polyamic acid; 3. preparation of a viscous sol-gel; and, 4. preparation of the thermoplastic shape-memory polyimide. The thermoplastic shape-memory polyimide prepared per the present invention is provided with a very fast shape recovery rate and improved shape-memory effect. The present invention is applicable in the field of polyimide preparation.

Laser fabricated graphene fiber which can be prepared from a fluorinated polyimide fiber is disclosed. The graphene fiber exhibits an ultrahigh specific surface area, facilitating excellent electrochemical properties, useful for example in tranducers, capacitors, and micro-supercapacitors.