1257 results about "Polyamic acid" patented technology

The invention belongs to the technical field of gel materials, and particularly relates to aerogel powder for polyolefin modification and a preparation method and application thereof. The preparation method of the aerogel powder comprises the following steps: (1) preparing aramid nanofiber dispersion liquid; (2) preparing a polypyrrole coated aramid nanofiber dispersion liquid; (3) mixing polyamide acid and the polypyrrole coated aramid nanofiber dispersion liquid, and then carrying out partial imidization and solvent exchange to prepare hydrogel; and (4) carrying out freeze drying, thermal imidization and crushing to obtain the aerogel powder for polyolefin modification. The aerogel powder is a porous solid material formed by forming one-dimensional composite fibers from aramid nanofibers and polypyrrole and combining the one-dimensional composite fibers with polyimide resin. The aerogel powder and polyolefin resin are compounded to obtain the polyolefin resin composite material with high strength and antistatic property, and the polyolefin resin composite material can be widely applied to the fields of pipes, plates, grouting equipment parts, grouting bags and the like.

The invention discloses a preparation method and application of a water-based polyamide acid sizing agent, and belongs to the technical field of sizing agents. The method comprises the following steps: synthesizing polyamic acid in an organic solvent by adopting dianhydride and diamine in a polymerization manner, after the reaction is finished, cooling a polyamic acid solution to room temperature, transferring into a dropping funnel, dropwise adding into a solvent of which the volume is 10-25 times that of the solution, separating, completely dropwise adding, collecting a precipitate, and drying to obtain solid polyamic acid; and adding a low-grade ester or low-grade ketone solvent into the deionized water, adding the polyamide acid powder into the mixed solvent according to the solid content of 1-20wt.%, stirring at room temperature until the solid disappears, and standing for liquid separation to obtain a lower layer which is the polyamide acid water-based sizing agent. The sizing agent disclosed by the invention shows excellent dispersity and long-term stability. After sizing, polyamide acid on the surface of the carbon fiber is converted into polyimide through a thermal imidization reaction, so that the carbon fiber has high thermal stability and excellent compatibility.

The invention provides a preparation method of an h-BN / PI high-temperature-resistant anticorrosive coating, and relates to the technical field of polymer composites.The preparation method of the h-BN / PI high-temperature-resistant anticorrosive coating comprises the steps that under the protection of inert atmosphere, aromatic diamine containing impurity element five-membered rings and aromatic dianhydride containing ether bonds are taken and subjected to a polymerization reaction in a polar aprotic solvent, and the h-BN / PI high-temperature-resistant anticorrosive coating is obtained. A polyamide acid solution is obtained; performing ultrasonic-assisted liquid phase stripping on the micron-sized hexagonal boron nitride to obtain single-layer hexagonal boron nitride; adding the single-layer hexagonal boron nitride into the polyamide acid solution for multiple times, and uniformly stirring to obtain a hexagonal boron nitride / polyimide composite solution; and coating the hexagonal boron nitride / polyimide composite liquid on a to-be-coated surface, and carrying out gradient heating curing to obtain the h-BN / PI high-temperature-resistant anticorrosive coating. The h-BN / PI high-temperature-resistant anticorrosive coating based on interaction of multiple hydrogen bonds has relatively good high temperature resistance, relatively good resistance mechanical property and excellent corrosion resistance.

The invention discloses CPVC (Chlorinated Polyvinyl Chloride) modification-based high-wear-resistance antistatic plastic and a preparation method thereof, belongs to the technical field of composite CPVC preparation, and aims to solve the technical problem that the wear resistance and the antistatic property of CPVC-based plastic in the prior art need to be further improved. The high-wear-resistant antistatic plastic based on CPVC modification comprises the following raw materials in parts by weight: 80-100 parts of modified CPVC, 6-8 parts of a modified heat stabilizer and 8-16 parts of an auxiliary material, the amino group on the surface of the prepared antistatic filler participates in the ammoniation process of the prepared CPVC, a large number of amino groups hybridize the chain segment structure of the CPVC and introduce tertiary amino groups, and an ion structure is introduced into the hybridized CPVC through quaternary ammonium salinization to obtain the modified CPVC. The CPVC-based plastic is obtained by mixing, melting and extruding the CPVC-based plastic, the prepared polyamide acid-based modified heat stabilizer and auxiliary materials.

The invention discloses liquid crystal polyimide aerogel with excellent shape memory performance and a preparation method of the liquid crystal polyimide aerogel, and belongs to the field of polymer aerogel materials. According to the liquid crystal polyimide aerogel with the excellent shape memory performance, the shape fixing rate is larger than or equal to 99%, and the shape recovery rate is larger than or equal to 97%; the heat conductivity at the room temperature is larger than or equal to 0.09 W m <-1 > K <-1 >; specifically, liquid crystal diamine, flexible diamine, a liquid crystal dianhydride monomer and a thermal curing agent are subjected to a reaction and solvent replacement, and polyamide acid dry filaments are obtained; and forming an aqueous solution from the dry polyamide acid filaments, injecting the aqueous solution into a silica gel mold, carrying out directional freezing casting on a customized freezing circulating device with a copper plate at the top, and carrying out freeze drying, thermal imidization and curing after molding, so as to obtain the liquid crystal polyimide aerogel with excellent shape memory performance.

The invention discloses an ionic liquid modified polyimide nanofiber film and an air purification filter screen based on the ionic liquid modified polyimide nanofiber film, and belongs to the technical field of film filtering materials. The preparation method comprises the following steps: firstly, selecting a diamine monomer and a dianhydride monomer to carry out low-temperature polycondensation reaction, and then carrying out solvent replacement and freeze drying to obtain polyamide acid powder; dissolving the powder to obtain a polyamide acid spinning solution, preparing an ionic liquid / polyamide acid spinning solution on the basis, and carrying out electrostatic spinning to obtain an ionic liquid / polyamide acid nanofiber membrane; and finally, carrying out high-temperature thermal imidization treatment to prepare the ionic liquid / polyimide nanofiber membrane. The method is simple and efficient, the problems of low resistance, high pressure drop and the like of a traditional nanofiber film in air filtration are solved, development and application of the nanofiber film in the field of air filtration are further widened, and the nanofiber film has important scientific significance and application value in the fields of high-temperature filtration, gas adsorption and the like.

The present application belongs to the field of polymer material technology, and in particular, relates to a polyimide composite material, a preparation method thereof, and an application thereof. The preparation method of the polyimide composite material comprises the steps of: preparing a polyamic acid slurry from a diamine monomer, a dianhydride monomer, and an organic solvent; preparing a mixed slurry from the polyamic acid slurry and a nanomaterial, and then performing a spinning imidization treatment to obtain a polyimide composite material; wherein the nanomaterial comprises at least one of nano silicon carbide, aluminum nitride, carbon nanotubes, graphene, and nano silicon dioxide. By blending polyimide with other nanomaterials having high thermal conductivity to improve its thermal conductivity, the thermal conductivity of the polyimide composite material is optimized and improved, and its heat dissipation capacity in a high temperature working environment is enhanced, while having high tensile strength and thermal conductivity. The service life of the polyimide composite material is extended, and its application range can be further expanded, such as in the back panel assembly of a smartphone.

The invention relates to a fluoride-free polyimide-based film and a preparation method thereof. The method comprises the following steps: S1, preparing a polyamide acid solution; s2, fluorine-free organic silicon serving as a modifier is added into the polyamide acid solution and dispersed, a blended spinning solution is formed, and the solubility parameter difference value of the fluorine-free organic silicon and polyamide acid is 2.0 (MPa) 1 / 2 or below; s3, carrying out electrostatic spinning on the blended spinning solution to form a polyamide acid-based nanofiber layer; and S4, carrying out thermal imidization on the polyamide acid-based nanofiber layer to obtain the fluoride-free polyimide-based film. The film has a structure formed by three-dimensional cross-linking and winding of polyimide-based nanofibers, and the polyimide-based nanofibers are composed of a polyimide base material and fluorine-free organic silicon dispersed in the polyimide base material. The method does not involve fluorine-containing raw materials, and is environment-friendly and high in process compatibility. The film provided by the invention has excellent waterproofness, air permeability and mechanical properties at the same time.

The invention belongs to the technical field of aerogel, and particularly relates to high-conductivity aerogel powder as well as a preparation method and application thereof. The preparation method comprises the following steps: firstly preparing a graphene / polypyrrole nanosheet composite material with a three-dimensional structure, and then preparing the polyimide / graphene / polypyrrole ternary hybrid conductive aerogel by taking a polyamide acid solution as a precursor through a solution dipping and freeze drying process. Polyimide is used as a framework of high-conductivity aerogel powder, excellent mechanical strength and structural integrity are provided, the common brittleness problem of a pure graphene carbon material or polypyrrole conductive polymer aerogel is solved, and the three-dimensional graphene / polypyrrole nanosheet composite material has excellent elasticity and toughness and can be used for preparing a composite material with high conductivity. The polyimide aerogel prepared by the method can be dispersed in a polyimide matrix as a nano reinforcement, can effectively transfer stress and prevent crack propagation, and endows the aerogel with higher mechanical properties.

The invention relates to the technical field of sizing agents, in particular to a water-based sizing agent for fibers as well as a preparation method and application of the water-based sizing agent for the fibers, the water-based sizing agent for the fibers comprises a component 1, a component 2 and water, the component 1 is polyamide acid salt, and the component 2 is at least one of sulfonated polyamide and lignosulfonate; the water-based sizing agent for the fibers comprises the following components in parts by weight: 0.1-15 parts of a component 1, 0.1-15 parts of a component 2, 0.1-15 parts of a component 3, 0.1-15 parts of a component 4, 0.1-15 parts of a component 5, 0.1-15 parts of a component 5 and 0.1-15 parts of a component 6, 0.1 to 15 parts of a component 2; and 70 to 99.8 parts of water. According to the water-based sizing agent for the fibers, the interface bonding strength of the fibers and a polyamide matrix can be high.

The invention discloses a high-cohesiveness polyimide composite film capable of being used for a flexible copper-clad plate and a preparation method of the high-cohesiveness polyimide composite film. The polyimide composite film is composed of a thermosetting polyimide supporting layer and a thermoplastic polyimide bonding layer arranged on at least one face of the thermosetting polyimide supporting layer. An interface layer formed by reacting amino-terminated hyperbranched polyamide grafted silicon dioxide particles with thermosetting polyamide acid is embedded between the thermosetting polyimide supporting layer and the thermoplastic polyimide bonding layer, and an end group of thermoplastic polyimide contains an imidazole ring capable of forming a complex with copper. The amino-terminated hyperbranched polyamide grafted silicon dioxide particles are embedded into the interface of the thermosetting layer and the thermoplastic layer, so that the contact area of the supporting layer and the adhesive layer is increased; the polyimide composite film with high cohesiveness, high dimensional stability, high heat resistance and low glass transition temperature is prepared.

The present invention discloses a liquid crystal alignment agent, including a polyamic acid-polyimide copolymer and an organic solvent. The block polymer in the polyamic acid-polyimide copolymer is prepared by a diamine component comprising a structure shown in the following formula (1) and at least one dianhydride component selected from cyclobutane tetracarboxylic dianhydride shown in the following formula (3-1) and 1,3-dimethylcyclobutane tetracarboxylic dianhydride shown in the following formula (3-2); In formula (1), X1 and X2 each independently represent a single bond or an alkyl group with 1 to 6 carbon atoms; Y1 and Y2 each independently represent one or more of -NHCO-, -CONH-, -OCO-, -COO-; Ar is a nitrogen-containing heterocyclic structure. The present invention can provide a liquid crystal alignment film for a lateral electric field driven liquid crystal display element endowed with high mechanical strength and high transmittance and a liquid crystal display element having the liquid crystal alignment film.

The invention discloses a copolyimide film with low dielectric constant and low thermal expansion coefficient and a preparation method thereof, and the preparation method comprises the following steps: reacting 0.019-0.021 mol of aromatic dianhydride and 0.017-0.023 mol of diamine unit in 0.45-0.48 mol of solvent, then adding 0.0004 mol of end-capping reagent dissolved in 0.13-0.15 mol of solvent, and reacting to prepare polyamide acid with a main chain containing o-hydroxyl; the diamine unit comprises 10-40 mol% of a monomer with a main chain containing o-hydroxyl and the balance of aromatic diamine; performing film coating and thermal imidization on polyamide acid to prepare a polyimide film; and heating to carry out thermal rearrangement reaction on the o-hydroxyl to obtain the copolyimide film with the main chain containing the oxazole ring. The dielectric constant of the prepared copolyimide film is 2.7-3.0, and the thermal expansion coefficient of the copolyimide film is 19.5-26.5 ppm / K.

The invention relates to a preparation method of a porous polyimide low-dielectric material. The method comprises the following specific steps: preparing a polyamide acid solution with a certain solid content under an ice-water bath condition; after the solution is recovered to normal temperature, adding a certain amount of sodium alginate, and after the solution is homogenized, adding a catalyst and a dehydrating agent for chemical imidization; the method comprises the following steps: coating a substrate medium with a solution after a certain time of reaction, standing in air for a certain time, sequentially and respectively placing the substrate medium in ethanol and a hot water bath for replacement for a certain time, airing at normal temperature, and transferring to a high-temperature oven for gradient cyclization to realize complete imidization. According to the method, conditions are mild and easy to control, and the low-dielectric film material which is flat in appearance and ordered in structure is prepared only through a normal-pressure drying method.

The invention provides a polyimide multilayer composite membrane material as well as a preparation method and application thereof, and belongs to the technical field of gas separation. According to the method, through collaborative design of a functional support layer, a gradient MOF layer and an ultrathin selection layer structure, the problems of support layer pore seepage, MOF agglomeration, weak interface bonding and the like in an existing composite membrane material are solved. The preparation method comprises the following steps: firstly, carrying out electrostatic spinning on a polyamide acid glue solution, and synchronously introducing dopamine by adopting a chemical imidization method to prepare a functionalized polyimide fiber membrane containing hydroxyl and amino on the surface, so that the mechanical property of a supporting layer and the MOF anchoring capability are remarkably improved; growing MOF layers with different particle sizes on the surface of the fiber membrane by regulating and controlling the concentration gradient of ligand / metal salt and the reaction time, and passivating through a silane coupling agent after each step of growth so as to avoid heterogeneous nucleation and construct a gradient structure; after the MOF gradient layer is subjected to Ar plasma pretreatment to introduce hydroxyl, the ultrathin polyamide selection layer is formed by utilizing interfacial polymerization of fluorine-containing acyl chloride and a macrocyclic amine monomer, and the ultrathin polyamide selection layer is suitable for gas separation work.

The invention relates to a use method of a micro-phase separated polyimide sizing agent for carbon fibers, which comprises the following steps: synthesizing polyamide acid with rigid and flexible chain segments alternately arranged by using a dianhydride monomer and a diamine monomer as raw materials, coating the polyamide acid on the surface of the carbon fibers, carrying out heat treatment, carrying out thermal cyclization on the polyamide acid to form polyimide, and carrying out body self-assembly at the same time, thereby obtaining the micro-phase separated polyimide sizing agent for the carbon fibers. And thus, the micro-phase separated polyimide coating is obtained. According to the method, the interface performance of the carbon fibers and the base material in the carbon fiber composite material can be improved, the thermal cyclization process of the sizing agent and microphase separation of the obtained surface coating are achieved at the same time through the heat treatment one-step method, and procedures and energy are saved.

The present application relates to the technical field of polyimides and relates to a preparation method for a high-performance polyimide and an application thereof, aiming to solve the problems in the prior art such as numerous side reactions and severe impact on transparency caused by an excessively high imidization reaction temperature during the use of a high-temperature thermal imidization method for the preparation of polyimides. The preparation method comprises: (1) preparing a polyamic acid solution; (2) adding a chemical catalyst and a polyamic acid solution to partially complete an imidization reaction; (3) adding an end group auxiliary agent, performing coating with the solution, heating, and maintaining the heat to complete the imidization reaction; and (4) carrying out high-temperature treatment to obtain a high-performance polyimide. The present application can significantly reduce numerous side reactions present in a traditional imidization reaction, eliminate an adverse effect of high-temperature imidization on the optical performance, greatly improve the mechanical properties, heat resistance, optical performance, etc. of a material, and also achieve both high heat resistance and high transparency.

The invention provides a polyimide-based dielectric heat-conducting composite material and a preparation method thereof.The preparation method comprises the steps that a hexagonal boron nitride nanosheet is modified through polydopamine to obtain a modified boron nitride nanosheet (MBN), and the modified boron nitride nanosheet (MBN) is mixed with a polyamide acid (PAA) solution to obtain an MBN / PAA solution; mBN is directionally distributed in PAA nanofibers through an electrostatic spinning technology, meanwhile, dispersion liquid of silver wires is electrostatically sprayed, and the silver wires serve as a bridge, so that a heat conduction path is constructed under the condition that less filler is doped; finally, the MBN-AgNW / PI dielectric heat-conducting composite material is prepared through a staggered stacking-compression molding-thermal imidization technology, and the prepared composite material is good in heat conductivity, low in dielectricity and high in insulativity and has huge application potential in electronic packaging equipment.

The invention belongs to the technical field of lithium ion batteries, and discloses a carboxyl-containing copolyimide binder, a lithium ion battery silicon negative electrode, a lithium ion battery and a preparation method, and polyamide acid is prepared by using a carboxyl-containing diamine monomer, an amino-terminated long aliphatic chain diamine monomer and an anhydride monomer as raw materials; and carrying out chemical imidization, precipitation and washing on the polyamide acid to obtain the carboxyl-containing copolyimide binder. The prepared carboxyl-containing copolyimide binder has good solubility in a conventional electrode manufacturing solvent, and the solution system of the obtained carboxyl-containing copolyimide binder is uniform and stable. When the carboxyl-containing copolyimide binder is applied to preparation of a silicon negative electrode of a lithium ion battery, the carboxyl-containing copolyimide binder can generate dual covalent interface interaction with silicon active material particles and conductive material particles, so that the migration efficiency of lithium ions in an electrode system is remarkably improved, the transmission dynamics performance is enhanced, and the high-rate charge-discharge capacity of the battery is effectively improved.

The invention discloses a flame-retardant flexible circuit board and a preparation method thereof, and relates to the technical field of flexible circuit boards, and the preparation method comprises the following steps: in an organic solvent, mixing a diamine monomer and a dianhydride monomer, carrying out a stirring reaction, and adding a filler to obtain a polyamide acid solution; casting to form a film, and drying to form a polyamide acid film; performing thermal imidization to obtain a polyimide film; adding a cross-linking agent into the polyamide acid solution to form a cross-linked solution; coating two surfaces of the polyimide film with a cross-linking solution, and drying to form a polyamide acid coating film; carrying out thermal imidization again to form a polyimide coating so as to obtain a base film; and setting a conductive circuit to obtain the circuit board. The cross-linking agent is added into the polyamide acid solution, so that the cross-linking density of the coating is effectively increased, a network structure is formed, and the stability of polyimide is improved, thereby improving the mechanical property, heat resistance and dielectric property of the prepared base membrane.

The invention discloses a kind of preparation method of amino hyperbranched siloxane and its modified polyimide aerogel material.First, alkoxysilane X with amino active functional group, alkoxysilane Y of inactive functional group and water are carried out autocatalytic controlled hydrolysis condensation under sub-stoichiometric ratio, obtain multifunctional group (such as other active groups, alkoxyl group, amino) amino hyperbranched siloxane liquid (HPSi NH2) with controllable amino content, then using HPSi NH2 as cross-linking agent and anhydride-terminated polyamic acid solution reaction to obtain functionalized polyamic acid, which is stirred with tertiary amine and deionized water to obtain functionalized polyamic acid wet gel, which is passed through freeze drying, high temperature imidization treatment to obtain amino hyperbranched siloxane modified polyimide aerogel material. This material has excellent flexibility, resilience, heat resistance and flame retardancy, and can be applied to aerospace, communication, catalysis and filtration fields.

The invention relates to the field of polyimide materials, in particular to a positive photosensitive polyimide photoresist, a polyimide film and application of the positive photosensitive polyimide photoresist and the polyimide film. The positive photosensitive polyimide photoresist with excellent performance can be prepared by taking novel water-soluble polyamic acid ester with good dielectric property, low water absorption, heat resistance and the like as film-forming resin and combining the film-forming resin with the quinonediazide compound photosensitive component, the silane coupling agent and the organic solvent; the main film-forming component polyamic acid ester is a corresponding water-soluble polyimide precursor synthesized by using a series of simple and easily available polymeric monomers, and the realization of the water solubility is not limited to specific groups such as hydroxyl, carboxyl and the like in molecules. The photoresist has the advantages of high light sensitivity, high resolution, good thermal stability and chemical resistance, good heat and humidity resistance, good adhesion to various substrates and the like, an alkaline aqueous solution can be used as a developing solution, the loss of a film in a non-exposure area in the developing process is low due to low water absorption of the alkaline aqueous solution, and the developing time is short.

The invention discloses a wide-temperature energy storage aerogel / polymer composite material and a preparation method thereof.The preparation method comprises the steps that oxide aerogel with a three-dimensional skeleton structure is subjected to silanization treatment to obtain hydrophobic oxide aerogel, then the hydrophobic oxide aerogel is dispersed into a solvent to obtain dispersion liquid, and then the dispersion liquid is subjected to ultrasonic treatment to obtain the wide-temperature energy storage aerogel / polymer composite material. The preparation method comprises the following steps: sequentially adding a diamine monomer and an anhydride monomer into a dispersion liquid, reacting under stirring to obtain a polyamide acid precursor solution dispersed with hydrophobic oxide aerogel, carrying out film casting on the polyamide acid precursor solution to obtain a dry film, and carrying out imidization treatment on the dry film to obtain the aerogel / polymer composite material. The obtained aerogel / polymer composite material can still maintain high energy storage performance and stability even at extreme ambient temperature.

The invention discloses a bending-resistant and low-dielectric transparent polyimide film for a flexible electronic device as well as a preparation method and application of the bending-resistant and low-dielectric transparent polyimide film. The surfaces of glass beads are subjected to grafting modification treatment by adopting alkali liquor and a coupling agent; performing ultrasonic dispersion to uniformly disperse the grafted and modified glass beads in a solvent; the preparation method comprises the following steps: dissolving a fluorine-containing diamine monomer in a solvent containing graft modified glass beads under a nitrogen protection atmosphere, after the fluorine-containing diamine monomer is completely dissolved, slowly adding a fluorine-containing dianhydride monomer in batches under a continuous stirring condition, and preparing a transparent polyamide acid solution containing glass beads through a condensation polymerization reaction; and uniformly coating the polyamide acid solution containing the glass beads on a glass substrate through a blade coating machine, and then carrying out gradient heating to obtain the glass bead compounded transparent polyimide film. Fluorine atoms are introduced into molecular structures of dianhydride and diamine, and grafting modified glass beads are doped to serve as filler, so that the transparent polyimide film with bending resistance and low dielectric constant characteristics is successfully prepared.

The invention discloses a low-dielectric polyimide film material and a preparation method and application thereof, and relates to the technical field of film material preparation, and the molecular structure of a polyimide copolymer in the polyimide film material comprises structural units shown in general formulas (1) and (2), the polyimide copolymer comprises aromatic ether, fluorine atoms or fluorine-containing groups and siloxane units, at least one of C and D in the structural units contains fluorine atoms or fluorine-containing groups, and the molar ratio of the content of the copolymerization components x: y: z is (1-90%): (1-50%): (1-30%). According to the preparation method, a batch feeding synthesis mode is adopted, molecular chain growth of polyamide acid is controlled through the feeding ratio, the salt forming effect of silicon-containing diamine and polyamide acid is avoided, and high-molecular-weight polyimide is obtained. The polyimide film prepared by the method has the characteristics of low dielectric constant and dielectric loss, low water absorption, good adhesion and the like, and can be applied to the fields of high-frequency and high-speed integrated circuits and the like.

The invention relates to a high-orientation polyimide fiber based on liquid crystal spinning and a preparation method of the high-orientation polyimide fiber. Rigid anhydride is used as a raw material to prepare para-diacid diester, and the para-diacid diester and rigid diamine are polymerized to prepare a full-para polyamic acid ester solution with lyotropic liquid crystal characteristics; and then adding an organic base catalyst to prepare a spinning solution, and carrying out high-temperature dry spinning, catalytic cyclization and high-temperature heat treatment to prepare the high-orientation polyimide fiber. According to the invention, an organic base catalyst is introduced into a spinning solution with lyotropic liquid crystal characteristics, and the high orientation of a liquid crystal domain along a fiber axis is realized by virtue of the shearing and fluid stretching effects of spinneret orifices; then, on the basis of high-temperature dry spinning and catalytic cyclization reaction, structural transformation from polyamide acid ester to polyimide is achieved while curing forming of the fiber is promoted, locking of an oriented structure and densification of the interior of the fiber are achieved, and therefore the stability and uniformity of the fiber are guaranteed; the method has great application potential in the field of extreme special environments such as aerospace.

The invention discloses a high-temperature-resistant and corrosion-resistant coating for an aluminum alloy heat exchange tube and a preparation method thereof, and relates to the technical field of coating materials. The method comprises the following steps that the aluminum alloy heat exchange tube is cleaned and deoiled, then a treating agent is sprayed, composite coating slurry is sprayed to the surface of the aluminum alloy heat exchange tube after curing, and the high-temperature-resistant and corrosion-resistant coating for the aluminum alloy heat exchange tube is obtained after curing treatment. Wherein the treating agent is prepared from NS-30 silica sol, deionized water and methyltrimethoxysilane; the composite coating slurry is prepared from a polyamide acid solution, a synergist, functionalized boron nitride nanosheets, modified hexagonal boron nitride, a flatting agent and a defoaming agent. The silane film introduced into the treating agent and the synergist, the functionalized boron nitride nanosheet and the modified hexagonal boron nitride introduced into the composite coating slurry effectively improve the high temperature resistance, the corrosion resistance, the adhesive force, the thermal conductivity, the aging resistance and the toughness of the coating. Therefore, the method has a wider application prospect.

The invention relates to the technical field of vacuum bag films for aeronautical manufacturing, and discloses an eleven-layer co-extruded film for aeronautical use and a preparation process thereof, and the preparation process specifically comprises the following steps: carrying out grafting modification treatment on polyamide acid by using a monoalkenyl diepoxy composite flexible compound through a carboxyl-epoxy ring-opening reaction to prepare alkenyl functionalized processable polyimide; the preparation method comprises the following steps: carrying out modification treatment on nylon 6 resin by using 3-mercaptopropionic acid through an amino-carboxyl condensation reaction to prepare mercapto functionalized nylon; under the hot melting condition, alkenyl functionalized processable polyimide and sulfydryl functionalized nylon are induced to be subjected to reactive compounding through a free radical initiator, PA-PI alloy master batch is prepared, the master batch serves as a functional modification component of copolymerized polyamide 6 / 66 resin, an eleven-layer co-extrusion film is prepared through an eleven-layer co-extrusion blow molding process, and the eleven-layer co-extrusion film is used as a functional modification component of the copolymerized polyamide 6 / 66 resin. The film product has excellent comprehensive performance and can be used as a high-temperature-resistant vacuum bag film for curing aviation composite materials.

The invention discloses negative photosensitive polyamic acid, photosensitive resin and a preparation method and application of the negative photosensitive polyamic acid and the photosensitive resin. The negative photosensitive polyamic acid is prepared from diamine and a dianhydride compound as monomers through end capping of anhydride containing a norbornene group; the photosensitive resin is formed by mixing negative photosensitive polyamide acid, polythiol and a photoinitiator, and is applied to preparation of photoresist, photosensitive packaging adhesive, photocuring adhesive and the like; the photosensitive resin is subjected to ultraviolet curing and gradient imidization to prepare negative photosensitive polyimide cross-linked through polythiol, and the negative photosensitive polyimide has good thermal performance and photosensitive performance; the photosensitive resin is used for preparing photoresist and is a solution-developed negative photosensitive polyimide system, alkenyl of a polyamide acid terminal chain and sulfydryl of polythiol are subjected to a click reaction to construct a cross-linking point, the solubility of polyamide acid in an exposure area in an alkaline solution is reduced, a negative pattern is obtained, the preparation method is simple, and the cost is low. The pattern resolution and sensitivity are high, and the method is expected to be well applied to the fields of optics and electronics.

The invention relates to resin for electronic component packaging and a preparation method thereof, and belongs to the technical field of high polymer materials, the resin raw materials comprise epoxy resin, an organosilicon prepolymer, a polyamide acid solution, a modified core-shell structure filler, a polydimethylsiloxane alcohol-methylsilanol-silicate ester cross-linked polymer, a silane coupling agent and the like. The resin matrix adopts an organosilicon-epoxy-polyimide-cross-linked polymer quaternary interpenetrating network, the functional filler adopts a specially modified core-shell heterostructure functional filler, the performance breakthrough is realized through a novel composite system and a step-by-step controllable process, and the composite material has good filling property, thermal conductivity and stability, and is suitable for large-scale production. Good packaging of electronic components can be realized, and the service life is long.