The polyamide-imide block copolymer according to the present invention makes it possible to provide a polyamide-imide film having excellent thermal stability and chemical resistance and, at the same time, having excellent mechanical properties.

A photosensitive resin composition including a polyimide resin (A) having a specific structure and a weight average molecular weight of 70000 or less is provided.

A branched polyimide of the formula (I) wherein G is a group having a valence of t, present in an amount of 0.01 to 10 mol %, or 0.05 to 5 mol %, or 0.1 to 4 mol %, or 0.1 to 3 mol %, each of Q, M, D, V, and R are as defined herein, q is 0 or 1, m is 0 or 1, d is 0 or 1, p is 1 or 2, t is 2 to 6, preferably 2 to 4, and each n is independently the same or different, and is 1 to 1,000, provided that the total of all values of n is greater than 4, wherein the branched polyimide has a zero-shear viscosity in a range from 500 to 15,000 Pa.Math.s, a rheology ratio of 1.1 to 5, and a strain hardening ratio of 1 to 6. ##STR00001##

Provided are a compound represented by formula (Ia) below, a polymer obtained by using the compound as a synthesis raw material, a gas separation membrane having a gas separation layer including the polymer, and a gas separation module and a gas separation apparatus that have the gas separation membrane.

##STR00001##

R.sup.A and R.sup.B represent a hydrogen atom, an alkyl group, or a halogen atom.

L.sup.A represents —CF.sub.2—, —CF(CF.sub.3)—, —C(═O)—, —CH.sub.2—, —CH(CH.sub.3)—, or —CH(CF.sub.3)— or a group obtained by combining the foregoing groups. L.sup.A has 4 or less carbon atoms.

An oligomer including two ends and a main chain located between the two ends, a group represented by Chemical Formula 1 at one end and a structural unit represented by Chemical Formula 2 or Chemical Formula 3 in the main chain: ##STR00001## wherein, in Chemical Formulae 1 to 3, R.sup.1, Ar.sup.1, and Ar.sup.2 are the same as defined in the detailed description.

The present invention provides an electrochromic polyamic acid material, a preparation method thereof and a display device, wherein the molecular structure of the electrochromic polyamic acid material includes oligoaniline and carbazolyl triphenylamine. The oligoaniline serves as an electrochemically sensitive group, and the carbazolyl triphenylamine serves as a fluorescence emitting group. The electrochromic polyamic acid material is an electrically controlled fluorescent polymer. Fluorescence intensity of the electrochromic polyamic acid material undergoes reversible fluorescence conversion with a change of an applied voltage, due to a redox reaction of the oligoaniline at different voltages, resulting in an interchange between a benzene ring and an anthracene ring in a molecular structure, and an electron/energy transfer path with the fluorescence emitting group are generated or eliminated, thereby realizing the electrically controlled fluorescent properties of the electrochromic polyamic acid material.

A cross-linked polyimide of the reaction product of a crosslinking agent and a polyimide. The cross-linking agent having at least two cross-linking moieties and the polyimide has a plurality of polyimide chains having an aryl constituent with a moiety comprised of a reactive substituent. The polyimide has crosslinks from the reaction of the reactive substituent of the aryl constituents of the polyimide chains and the cross-linking moieties of the cross-linking agent. The cross-linking may be induced by thermally treating a mixture of the polyimide and crosslinking agent above about 150° C. to a temperature where the polyimide begins to decompose under an inert atmosphere. The membrane can be used for separations involving gases such as hydrogen and light hydrocarbons.

A graphene-based membrane and a method of producing the same are disclosed. The graphene-based membrane may include a graphene-polymer composite, wherein the graphene-polymer composite may consist of an amine functionalized graphene and a polymer containing an anhydride group as a linker for linking the amine functionalized graphene to the polymer. The graphene-based membrane may be constructed of a single-layer. A method may include reacting a polymer containing an anhydride with an amine functionalized graphene in presence of a solvent to form an intermediate product; and thermal imidizing the intermediate product to form a graphene grafted polymer composite for use in fabricating a graphene-based membrane.

The present invention discloses a polyimide material, a preparation method thereof, and an electrochromic device, wherein the polyimide material has a polyhedral oligomeric silsesquioxane (POSS) as an end capping group. The present invention has the beneficial effects that the polyimide material, the preparation method thereof, and the electrochromic device of the present invention use an oligoaniline and a fluorescent triphenylamine fragments as raw materials to prepare a polyamic acid solution, and then introducing the polyhedral oligomeric silsesquioxane (POSS) as the end capping group of the polyimide material to give an electrochromic ability and stable electroluminescence to the polyimide material, which provides directional guidance for subsequent fluorescent displays and electrochromic devices.

Provided is a composition, with which it is possible, by means of a simple application process, to form an organic film that has excellent performance, such as optical and electrical properties, and exhibits optical anisotropy. This composition, which exhibits lyotropic liquid crystallinity, contains: a polymer (P) having an acidic functional group; water; and a compound (A) that is at least one selected from the group consisting of a basic monomer and a base-generating agent. The composition contains: a polymer (P) having a partial structure shown in formula (0); water; and a compound (A) that is at least one selected from the group consisting of a basic monomer and a base-generating agent. Formula (0) has at least one acidic functional group.