Abstract: This application provides a polyimide fiber and a preparation method thereof. This method comprises first subjecting a dianhydride compound and a diamine compound to a polymerization reaction in a solvent to obtain a polyamic acid solution, wherein said diamine compound comprises a diamine having a structure of Formula 12 or Formula 13, wherein A is S or O; said dianhydride compound comprises one or more of dianhydrides having structures of Formula 14 and Formula 15; and t is 0 or 1; then subjecting said polyamic acid solution to spinning to obtain a polyamic acid fiber; and sequentially subjecting said polyamic acid fiber to imidization and thermal drawing to obtain a polyimide fiber. The polyimide fiber having the above structure has a higher rigidity and can introduce a hydrogen bond to provide an interaction between molecular chains so as to influence the arrangement of the molecular chain in the polymer and the crystallinity, which imparts more excellent mechanical properties to the polyimide fiber.

Abstract: This disclosure provides a polyimide fiber prepared from a dianhydride compound and a diamine compound, wherein said diamine compound is selected from one or more of the compounds represented by the following formulae (I), (II), (III) and (IV). A polyimide fiber is prepared by using a polyimide polymer system having a specific hydroxyl heterocyclic diamine copolymerization structure, and the prepared polyimide fiber has relatively high strength and modulus and is resistant to high temperature. Furthermore, the polyimide fiber prepared by this disclosure is provided with an active group on its surface, thus being easily adhered to various resin matrices, and the composite material prepared has good mechanical properties.

Abstract: The present invention belongs to a bonding technical field of biochips or micromechanical electrical devices, more specifically, to a novel method for bonding two solid planes containing silicon, oxygen, metal or other elements at a moderate temperature via surface assembling of active functional groups. The method includes the steps of: (1) cleaning and hydroxylating solid planes of silicon plate, quartz or glass; (2) aminating a hydroxylated surfaces of the substrate; (3) forming a mono-layer or multi-layer assembled film with compound monomers having an active bi-functional or multi-functional group on an aminated substrate surface; and (4) contacting two solid planes with a assembled film having the same or different active functional groups on its surface tightly, and forming covalent bonds at an appropriate temperature, pressure and a vacuum degree.

Abstract: The present invention discloses a process for preparing dibasic salt of bisphenol from bisphenol and alkali, wherein the bisphenol and the alkali are reacted in a reaction medium consisting of an organic solvent or an aqueous inorganic salt solution, and then through filtration, a highly pure dibasic salt of bisphenol is directly obtained at a yield of higher than 90%.