3results about How to "Good dimensional stability at high temperature" patented technology

The present invention discloses a type of high specific surface area, low shrinkage, lightweight cross-linked polyimide aerogel material, and a preparation method and application thereof. The structure of the cross-linked polyimide aerogel is shown below, and the preparation method thereof is to carry out a condensation reaction of a material containing an aromatic dianhydride and an aromatic diamine containing a trifluoro group to obtain a polyamic acid oligomer, and then carry out a cross-linking reaction with the aromatic amine, and then dry and imidize to obtain an aerogel. The raw material of the present invention is a commercial product; the synthesis route is simple, the yield is high, and the synthesis method has universal applicability. The polyimide aerogel of the present invention has a high specific surface area, a shrinkage rate as low as 5%, very good dimensional stability, and good application prospects in extreme environments.

The application belongs to the technical field of thermoplastic polyester imides, and particularly relates to a biphenyl-bridged thermoplastic polyester imide, a preparation method thereof, a biphenyl-bridged thermoplastic polyester imide film and application. The biphenyl-bridged thermoplastic polyester imide is polymerized from biphenyl diphenylate-3,3',4,4'-tetracarboxylic dianhydride, 3,3',4,4',-biphenyl tetracarboxylic dianhydride and 2-(4-aminobenzoate)-5-aminobiphenyl. The biphenyl-bridged thermoplastic polyester imide provided by the application has a linear thermal expansion coefficient close to that of copper foil, and excellent thermoplasticity, high-temperature dimensional stability and dielectric properties.

The invention discloses an alumina vacuum ceramic sucker and a preparation method thereof, the preparation method comprises the following steps: mixing ceramic powder, carbon fiber, paraffin, polyethylene, polypropylene and stearic acid to obtain a feed; then, the feed is subjected to FDM 3D printing, a printed green body is cut into sheets, and a porous ceramic green body is obtained through solvent degreasing; and covering the surface of a porous ceramic body with the granulation powder, and carrying out dry pressing molding, isostatic pressing molding and sintering to obtain the alumina vacuum ceramic sucker. The alumina vacuum ceramic sucker has the advantages of high bonding strength, large air flux, excellent high-temperature dimensional stability and the like.