83 results about "BPDA" patented technology

The invention discloses a dimensionally-stable polyimide film and a preparation method thereof. According to the weight percentage, the polyimide film is manufactured by evenly mixing 40 to 80 percent of component A, 0 to 60 percent of component B and 0 to 60 percent of component C and then conducting slobbering and imidization according to a conventional process, wherein the component A is polyamide acid resin solutions obtained after 2-(4-aminophenyl)-5-amido-benzimidazole reacts with pyromellitic dianhydride (PMDA) or biphenyltetracarboxylic acid dianhydride (BPDA); the component B is polyamide acid resin solutions obtained after p-phenylenediamine (PDA) reacts with the PMDA; and the component C is polyamide acid resin solutions obtained after 4,4'-diaminodiphenyl ether (ODA) reacts with the BPDA and the PMDA. The polyimide film provided by the invention has the advantages of lower thermal shrinkage rate, lower thermal expansion coefficient, higher elastic modulus and higher tensile strength and reflects better dimensional stability. The whole preparation method is simple and is easy to operate.

A novel polyimide resin consisting essentially of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,4,3′,4′-biphenyltetracarboxylic dianhydride (BPDA), 2,2 bis (3′,4′-dicarboxy phenyl) hexafluoro propane dianhydride (6FDA), 2-(3,4-dicarboxyphenyl)-1-phenylacetylene anhydride (4-PEPA) and an aromatic diamine.

The invention belongs to the field of high polymer material, and in particular relates to a few kinds of polyimide with lower glass transition temperature as well as good mechanical properties, thermal stability and high UV transmittance and a method for preparing the same. The method comprises the steps of adding diamine 1,3-bis (3-amino phenoxy-4'-benzoyl) benzene, dianhydride (s-BPDA, a-BPDA, i-BPDA, BTDA, PMDA, ODPA, BPADA or 6FDA) into an organic solvent (DMF, DMAc or NMP ) to react for 2 to 24 hours in an ice-water bath at room temperature under nitrogen protection, or adding end-capping agent aniline or phthalic anhydride so as to obtain polyamic acid solution; then pouring the polyamic acid solution onto a clean glass sheet to remove the organic solvent in an oven after even scrapping; and then performing imidization on the polyamic acid solution in a vacuum oven to obtain a polyimide polymer film of no-sealed end, aniline sealed end, phthalic anhydride sealed end or dianhydride sealed end.

The invention discloses thermoplastic polyimide resin powder and a preparation method thereof. The preparation method comprises the steps that a low-temperature polymerization reaction is performed by adopting s-BPDA, BAPP and 2-(4-aminophenyl)-5-aminobenzimidazole as raw materials under protection of nitrogen in non-proton organic solvent to prepare a polyamic acid solution; organic solvent capable of co-boiling with water and the non-proton organic solvent are added, and a high-temperature polymerization dehydration reaction is performed under the refluxing temperature condition to prepare a polyamide acid-polyimide mixed solution; imidization is performed to obtain the thermoplastic polyimide resin powder. The glass-transition temperature of the finally obtained thermoplastic polyimide resin powder can reach about 330 DEG C and can reach about 280 DEG C if the thermoplastic polyimide resin powder is used for a long term.

The invention discloses thermoplastic polyimide resin and a preparation method thereof. According to the thermoplastic polyimide resin, 1, 2, 3, 4--biphenyl-tetracarboxylic acid dianhydride (BPDA) is reacted with other mixed dianhydride formed by common tetracarboxylic acid dianhydride, diamine and phthalic anhydride or aniline to polymerize the mixed dianhydride with the diamine, and the phthalic anhydride or the aniline serves as a blocking agent to control molecular weight, thus obtaining the polyimide resin with good thermal stability and excellent thermoplastic processability. The inherent viscosity of the polyimide resin can reach 0.22dL/g to 0.90dL/g, and the glass-transition temperature of the polyimide resin ranges from 220 DEG C to 420 DEG C, therefore, the polyimide resin has wide application in the preparation of materials such as thermostability engineering plastics, thin films, adhesives and the like.

The invention discloses a method for preparing biphenyltetracarboxylic dianhydride (BPDA). The method comprises the following steps: carrying out a reaction on tetramethyl biphenyls and gases containing molecular oxygen to obtain biphenyltetracarboxylic acid by taking acetic acid as a solvent, cobalt source compounds as catalysts and a bromine source compound as a promoter; and then carrying out dehydration on biphenyltetracarboxylic acid to obtain BPDA. Under the catalytic actions of the cobalt source compounds and the bromine source compound, the gases containing molecular oxygen are used as oxidants, tetramethyl biphenyls and the gases containing molecular oxygen are subjected to an oxidation reaction and BPDA is obtained after dehydration. Compared with the prior art, the method has the following beneficial effects: the gases containing molecular oxygen are used as oxidants; the oxidants have low cost and are environmentally-friendly; therefore the environment is protected while the cost is lowered; and the experimental results show that BPDA is obtained by the preparation method.

The invention provides a europium-terbium co-doped luminescent material. The material comprises one or more of the chemical compound as shown in the formula I, hydrates of the chemical compound as shown in the formula I and solvated compounds of the chemical compound as shown in the formula I, and the formula I is shown as Zn8 (Adenine)4(BPDA)6O EuxTb1-x I, wherein x is greater than 0.1 and less than 0.25, Adenine refers to adenine, and BPDA refers to 4,4'-biphenyldicarboxylic acid. Metal-organic frameworks with a porous structure serve as carriers, and the europium-terbium co-doped luminescent porous material is obtained through ion exchange with europium terbium rare earth. The co-doped luminescent porous material can efficiently transfer energy from terbium to europium, so that the material has changes of ratio fluorescence to a bacillus anthraci biomarker, and reduces possible measuring errors caused by changes of single fluorescence intensity. Moreover, the co-doped luminescent porous material can further concentrate molecules of the bacillus anthraci biomarker in the environment, and improve the detection limit of the bacillus anthraci biomarker.

The invention discloses a preparation method of a thin electronic polyimide film. The method comprises the following specific steps of 1) performing methyl esterification on 3,4'-BPDA and 4-PEPA to prepare white and yellowish esterification powder (PDE and PEPE), adding BPDE, PEPE and diamine to a solvent at a certain ratio, and performing heating and reflux stirring for 2h to obtain a red-brown synthetic polyamide acid solution, 2) performing filtration, vacuum defoamation, cast film forming, two-way stretch, high-temperature thermoforming treatment, corona treatment and reeling on the synthetic polyamide acid solution to prepare the electronic polyimide film with excellent physical and mechanical properties, and 3) allowing a surface organification modified superfine inorganic crystal whisker and/or a nano particle material and multi-polyamide acid to form in-situ micro-nano compounding to imidize the polyimide film by virtue of crushing and cavitation of high-energy density ultrasonic.

The invention belongs to a preparation method of a polyimide aerogel adsorption material. A sol-gel method is adopted, and a mixed diamine component of conventional polyimide aerogel is changed. Aromatic oxydianiline (ODA) and aliphatic 1,3-propane diamine are used as mixed diamine, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) is used as a dianhydride, 1,3,5-tris(4-aminophenoxy)benzene (TAB) is used as a cross-linking agent, acetic anhydride and pyridine are used as imidization reagents, and polyimide hydrogel is synthesized at normal temperature; replacing and aging is carried out onthe solution, and then CO2 supercritical drying is carried out to obtain the complete block-shaped polyimide aerogel. The polyimide aerogel prepared by the method has relatively low heat conductivityand good mechanical properties, and meanwhile, a flexible structure is obtained. Experiments prove that the polyimide aerogel can be used for adsorbing CO2. The density of the polyimide aerogel adsorption material is 0.08-0.11 g/cm<3>, the compression modulus is 2.03-3.26 MPa, and the CO2 adsorption amount is 8.2-11.5 cm<3>/g.

The invention provides a carbon fiber honeycomb reinforced polyimide foam material and a preparation method thereof. The foam material is obtained through a reaction of polyimide prepolymer powder and a carbon fiber honeycomb material. A preparation method of the polyimide prepolymer powder comprises the steps that BTDA and methyl alcohol are reacted for 1.5-2.5 h in a backflow state to prepare a 3,3',4,4'-benzophenone tetramethyl acid dimethyl ester solution, BPDA and methyl alcohol are reacted for 10-11 h in a backflow state to obtain a 3,3',4,4'-biphenyl tetracarboxylic acid dimethyl ester solution, the obtained 3,3',4,4'-benzophenone tetramethyl acid dimethyl ester solution and the obtained 3,3',4,4'-biphenyl tetracarboxylic acid dimethyl ester solution are mixed, MDA is added into the mixture, stirring is performed at room temperature for 0.5-1 h, a foam stabilizer is added, stirring continues to be performed for 0.5-3 h, a polyimide prepolymer solution is prepared, and the polyimide prepolymer solution is dried to obtain the polyimide prepolymer powder, wherein the mole ratio of the BTDA to the BPDA is (6-8):(2-4). The carbon fiber honeycomb reinforced polyimide foam material has uniform foam holes and quite high mechanical property and is low in production cost.

Disclosed is an organic-solvent-soluble, heat-resistant polyimide that comprises (a) a pyromellitic dianhydride (PMDA), (b) a biphenyl tetracarboxylic dianhydride (BPDA), (c) a bicyclooctene tetracarboxylic dianhydride (BCD), and (d) a diaminodiphenyl ether (DADE) as components. The organic-solvent-soluble, heat-resistant polyimide has a thermal decomposition initiation temperature in the range of 530 DEG C to 570 DEG C and is synthesized by means of a three-step hydrogenation reaction: in the first step, a low molecular weight imide compound is generated by the reaction of an acid dianhydride and an aromatic diamine; in the second step, a low molecular weight imide compound is generated by further reacting an acid dianhydride and an aromatic diamine with the low molecular weight imide compound generated in the first step; and in the third step, a polycondensation reaction is performed.

This invention relates to a polyamide-imide precursor, a polyamide-imide obtained by imidizing the same, a polyamide-imide film, and an image display device including the film. The polyamide-imide precursor includes, in a molecular structure thereof, a first block, obtained by copolymerizing monomers including dianhydride and diamine, and a second block, obtained by copolymerizing monomers including an aromatic dicarbonyl compound and aromatic diamine. The dianhydride includes biphenyltetracarboxylic acid dianhydride (BPDA) and 2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride (6FDA), and the diamine includes bistrifluoromethylbenzidine (TFDB).

Provided is a polyimide film having a non-thermoplastic polyimide layer, wherein: the non-thermoplastic polyimide constituting the non-thermoplastic polyimide layer preferably contains at least one ofa biphenyl-tetracarboxylic dianhydride (BPDA) residue derived from 3,3',4,4'-BPDA and a phenylenebis(trimellitic monoester) dianhydride (TAHQ) residue derived from 1,4-TAHQ, as well as at least one of a pyromellitic dianhydride (PMDA) residue derived from PMDA and a napthalenetetracarboxylic dianhydride (NTCDA) residue derived from 2,3,6,7-NTCDA, the total amount of these residues being at least80 mol parts with respect to 100 mol parts of a tetracarboxylic acid residue; and the dielectric loss tangent (Df) is preferably 0.004 or less.

The invention discloses a solid-phase extraction column which has a sulfonate functionalized covalent organic polymer (COPTPBA-BPDA@SA) as a filler, and a preparation method and application of the solid-phase extraction column. The preparation method of the solid-phase extraction column comprises the following steps: firstly, preparing a matrix covalent organic polymer (COPTPBA-BPDA) from 1,3,5-tri(4-ammonia phenyl) benzene (TPBA) and 4-biphenyldicarboxaldehyde (BPDA) as reaction raw materials; further enabling COPTPBA-BPDA to react with sulfanilic acid so as to obtain COPTPBA-BPDA@SA; and putting the COPTPBA-BPDA@SA into a stainless steel hollow column tube, so as to obtain the solid-phase extraction column. As the solid-phase extraction column filled with the COPTPBA-BPDA@SA is adopted as an extraction medium, an on-line solid-phase (micro) extraction-high performance liquid chromatography combined system is established, and thus enrichment extraction and purification on a nonpolar or weak-polarity analysis target or a positive ionized analysis target can be achieved. The solid-phase extraction column is simple in process, simple and convenient to operate, easy to popularize, wide in applicable analysis target and wide in application prospect.

An electric motor assembly configured for use in a downhole pumping system includes a number of electrically conductive components that are insulated from fluids, mechanical abrasion, electrical current and electrical grounds using an advanced polyimide film. Preferred polyimide films include poly(4,4′-oxydiphenylene-pyromellitimide) and biphenyl-tetracarboxylic acid dianhydride (BPDA) type polyimide films. Magnet wire, stator laminates, stator coil end turns, motor leads and power cables can all be insulated with the selected polyimide film.

A process for producing BPDA by which high productivity is attained while maintaining a high purity. The process for biphenyltetracarboxylic acid dianhydride production comprises heating biphenyltetracarboxylic acid to produce biphenyltetracarboxylic acid dianhydride, wherein the heat treatment is conducted at a pressure of 1*10²-1.1*10⁵ Pa to a maximum temperature in the range of 210-250 DEG C in such a manner that at least 1/4 the period used for heating from 60 DEG C to 210 DEG C has a heating rate of 50 DEG C/Hr or higher and that the acid is held at 150-250 DEG C for 0.5-10 hours.

Disclosed is a process for producing a polyimide film, which comprises applying a polyamic acid solution composition to a base material to form a coating film, and subsequently heating the coating film, wherein the polyamic acid solution composition comprises a mixed solvent of two or more solvents selected from N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone and 1,3-dimethyl-2-imidazolidinone (wherein each of the solvents is contained in an amount of 7 to 93 mass% relative to 100 mass% of the total amount of the solvents) and a polyamic acid mainly composed of s-BPDA and PPD. The process enables to produce a polyimide film having a film thickness of more than 40 [mu]m without the need of expanding the film.

The invention discloses a g-C3N4-doped polyimide composite material which is prepared by the following steps: polymerizing a diamine monomer ODA (diaminodiphenyl ether) and another dianhydride monomer PMDA (pyromellitic dianhydride) or BPDA (3,3',4,4'-biphenyl dianhydride) to form polyamic acid, wherein graphite carbon nitride (g-C3N4) is added before the polyamic acid solution formation process; and after the system is imidized, carrying out hot pressing to form the g-C3N4-doped polyimide composite material. The g-C3N4 is doped into the polyimide system under the physical action. The g-C3N4-containing polyimide film material obtained by the method has favorable thermal neutron shielding property. The invention also discloses a preparation method of the g-C3N4-doped polyimide material and application of the g-C3N4-doped polyimide material in neutron radiation shielding.

A high-strength high-modulus polyimide fiber and its preparation method pertain to the technical field of high-performance organic fiber. This fiber includes the polyimide (PI) fiber made from 3,3′,4,4′-biphenyl tetracarboxylic diandhydride (BPDA), p-phenylenediamine (pPDA) and 2-(4-aminophenyl)-1H-benzimidazol-5-amine (BIA), wherein the molar ratio between PPDA and BIA is 1:10˜3:1. During the synthesis, other diamine and diandhydride monomers may also be added. In the preparation process, the gradient temperature reaction method and one-step continuous preparation method are adopted, the synthesis and processing difficulty caused by the increase of the content of BIA is overcome, the problem of poor uniformity and stability of fiber is solved and PI fiber with high strength and high modulus is obtained. Its strength may reach 4.5 GPa and modulus may reach 201 GPa. Moreover, the sources of the raw materials are extensive, the spinning process is continuous, the cost is low, the efficiency is high and industrial production may be realized.

The invention discloses a method for improving a polyimide-based carbon fiber microstructure and belongs to the technical field of carbon fibers. The method comprises that BPDA, p-PDA and ODA monomers are synthesized into polyamic acid solutions with different molecular chain plane regularities, through a wet spinning technology and gradient heating heat amidation, polyimide fibers are prepared from the polyamic acid solutions, the polyimide fibers are fixed into a vacuum tube furnace and are heated for carbonization to a temperature of 1500 DEG C in a N2 protective atmosphere, and then the carbonization product is naturally cooled so that the polyimide-based carbon fibers are obtained. The polyimide fiber chemical structure has high plane regularity. The polyimide-based carbon fiber has a perfect microstructure. The invention provides the method for improving a polyimide-based carbon fiber structure. The prepared polyimide-based carbon fiber retains polyimide base fiber morphology characteristics, and has good compactness, less defects, high carbon content and conductive characteristics.