The present invention relates to a pickering emulsion composition using polyimide particles and a method for preparing the same. The pickering emulsion stabilized by the polyimide particles according to the present invention has a very stable dispersed phase and does not cause flocculation, creaming, coalescence and phase separation even after a long time, and has an advantage of being capable of forming both an oil-in-water type emulsion and a water-in-oil type emulsion. Further, the polyimide particles used in the present invention can be synthesized in a simple manner and have partial wettability without the surface treatment and pH control so that they can be easily used for the emulsion stabilization.

In a first aspect, a single layer polymer film includes 60 to 99 wt % of a crosslinked polyimide, having a gel fraction in the range of from 20 to 100% and a refractive index of 1.74 or less, and 1 to 40 wt % of a colorant. A surface of the single layer polymer film has been textured and has a maximum roughness (S.sub.pv) of 6 μm or more, an L* color of 30 or less and a 60° gloss of 15 or less. In a second aspect, a coverlay for a printed circuit board includes the single layer polymer film of the first aspect. In third and fourth aspects, processes are disclosed for forming a single layer polymer film including a crosslinked polyimide film including a dianhydride and a diamine.

The present disclosure provides a thin film material and a manufacturing method thereof. The manufacturing method of the thin film material comprises: a compound A and a first reactant reacting to form a compound B; the compound B and a second reactant reacting to form a compound C; the compound C and a third reactant reacting to form a polymer D; the polymer D reacting to obtain a mixture including a polymer F or a polymer H; and a solution including the polymer F or the polymer H forming the polymer F or the polymer H on a substrate.

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.

The present invention discloses a modified bismaleimide resin and preparation method thereof; under conditions of N,N-dimethylformamide serving as a catalyst, biomass-based 2,5-furandicarboxylic acid and thionyl chloride are acylated to obtain 2,5-furan diformyl chloride, which is then dissolved in dichloromethane with a biomass-based eugenol; under tertiary amine conditions an esterification reaction takes place, and a fully biomass-based bis(4-allyl-2-methoxyphenyl)furan-2,5-dicarboxylic acid ester is thus obtained; same is used for preparing a modified bismaleimide resin. The bismaleimide resin prepared by the present invention has excellent thermal properties and rigidity; the preparation method uses 2,5-furandicarboxylic acid from biomass as well as eugenol; the raw materials are green and environmentally friendly and renewable; the invention also has the feature of a simple production process, and has broad prospects for application in such fields as aeronautics and astronautics, electronic information, electrical insulation.

A method for manufacturing a poly(imide) prepolymer varnish includes combining a bisanhydride powder or organic diamine and a solvent 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 varnish can have a residual organic diamine content of less than or equal to 1000 ppm. A poly(imide) polymer prepared from the prepolymer varnish is also disclosed.

In a first aspect, a polyimide film includes a dianhydride and a diamine. The dianhydride, the diamine or both the dianhydride and the diamine include an alicyclic monomer, an aliphatic monomer or both an alicyclic monomer and an aliphatic monomer. The polyimide film has a b* of 1.25 or less and a yellowness index of 2.25 or less for a film thickness of 50 m. The polyimide film is formed by: (a) polymerizing the dianhydride and the diamine in the presence of a first solvent to obtain a polyamic acid solution; (b) imidizing the polyamic acid solution to form a substantially imidized solution; (c) casting the substantially imidized solution to form a film; and (d) drying the film.

In a first aspect, a polyimide film includes a dianhydride and a diamine. The dianhydride, the diamine or both the dianhydride and the diamine include an alicyclic monomer, an aliphatic monomer or both an alicyclic monomer and an aliphatic monomer. The polyimide film has a tensile modulus of 5.5 GPa or more, a b* of 1.4 or less and a yellowness index of 2.25 or less for a film thickness of 50 m. In a second aspect, an electronic device includes the polyimide film of the first aspect.

A method of preparing a polyimide film, comprising: dissolving an aromatic diamine monomer in a solvent, adding a silane coupling agent, stirring uniformly, and further adding a dianhydride monomer to carry out polycondensation to obtain a polyamic acid solution; oating the polyamic acid solution on a glass substrate, followed by drying, and then carrying out a thermal imidization under vacuum, and naturally cooling to room temperature to obtain the polyimide film. As such, adhesion between the polyimide and the substrate can be enhanced, thereby improving a problem of separation of the two substrates due to poor adhesion.

Boron nitride nanotube (BNNT)-polyimide (PI) and poly-xylene (PX) nano-composites, in the form of thin films, powder, and mats may be useful as layers in electronic circuits, windows, membranes, and coatings. The processes described chemical vapor deposition (CVD) processes for coating the BNNTs with polymeric material, specifically PI and PX. The processes rely on surface adsorption of polymeric material onto BNNTs as to modify their surface properties or create a uniform dispersion of polymer around nanotubes. The resulting functionalized BNNTs have numerous valuable applications.