24results about How to "Solve the brittleness problem" patented technology

The invention relates to the field of shielding materials, and provides lead-free rubber with ionizing radiation shielding performance and a preparation method thereof, and the lead-free rubber is mainly prepared from barium titanate / boron nitride composite filler, barium tungstate / boron carbide composite filler, tungsten powder, bismuth powder, a rubber matrix and an auxiliary agent according to a proportion. The barium titanate particles are uniformly loaded on the surface of the flaky boron nitride, so that the gamma ray and X ray shielding performance is improved, and meanwhile, the boron nitride provides excellent neutron shielding capability; barium tungstate particles are loaded on the surfaces of the boron carbide nanowires to form a multi-scale shielding network, and the shielding effect of neutrons and ionizing radiation is remarkably enhanced. The rubber matrix endows the material with excellent flexibility and mechanical properties. By scientifically optimizing the component proportion and the preparation process, the problems that a traditional high-density shielding material is prone to agglomeration, poor in flexibility and the like are solved, and the material shows excellent performance in the fields of gamma ray, X ray and neutron shielding and is suitable for the fields of nuclear energy, medical protection, industrial radiation protection and the like.

The invention relates to the field of carbon-ceramic composite materials, in particular to a chopped carbon fiber reinforced carbon-ceramic composite material and a preparation method thereof.The chopped carbon fiber reinforced carbon-ceramic composite material is prepared from, by weight, 10-60 parts of chopped carbon fibers, 10-60 parts of silicon carbide powder, 10-60 parts of carbon powder, 10-60 parts of phenolic resin and 0.1-10 parts of graphene; the prepared carbon-ceramic composite material has good mechanical properties and excellent wear resistance, the densification process of the material is rapid and does not need to be repeatedly carried out, the time is saved, and the production efficiency is improved.

The invention discloses a layered network microstructure carbon aerogel material, a flexible pressure sensor and a preparation method and application of the layered network microstructure carbon aerogel material and the flexible pressure sensor, and the preparation method of the layered network microstructure carbon aerogel material comprises the following steps: (1) taking bamboo fibers as a raw material, and adopting a TEMPO oxidation method to prepare nanocellulose dispersion liquid; (2) mixing the nanocellulose dispersion liquid with a graphene oxide dispersion liquid and a chitosan solution, performing ultrasonic treatment, freezing by adopting a bidirectional ice template method, and performing freeze drying; and (3) carrying out low-temperature hydrothermal reduction treatment to obtain the layered network microstructure bamboo cellulose carbon aerogel. According to the carbon aerogel material prepared by the invention, the nanocellulose is used as a network skeleton, the graphene oxide is tightly combined with the nanocellulose through hydrogen bond interaction, the graphene oxide is reduced into reduced graphene oxide, and the reduced graphene oxide is combined through pi-pi interaction and is used as a conductive unit to provide the overall conductivity of the aerogel; the conductive unit can be prevented from falling off in the repeated use process, and transmission and acquisition of sensor signals are facilitated.

The invention relates to the technical field of bulletproof armor, in particular to a bionic ceramic armor module and a preparation method thereof. The bionic ceramic armor module comprises a plurality of ceramic bulletproof layers and nano energy-absorbing adhesive bonding layers which are stacked in a staggered mode, each ceramic bulletproof layer comprises a plurality of ceramic pieces, the ceramic pieces are arranged in order in an array mode, the ceramic pieces are tightly bonded through pouring of nano energy-absorbing adhesives to form single thin layers, and the single thin layers are sequentially stacked in a staggered mode; nano energy-absorbing glue is sprayed between every two layers of the single thin layers to form a nano energy-absorbing glue bonding layer, and the ceramic bulletproof layer and the nano energy-absorbing glue bonding layer form a composite whole. The bionic ceramic armor module is rigid and flexible, good in toughness, high in energy absorption density and light in weight, and the multi-time anti-penetration capacity is greatly improved. Different modules with different layer numbers, thicknesses, hardness, weights, size specifications and anti-penetration strengths can be programmed and designed according to actual purposes, and the application range is wide.

The invention discloses heat-resistant modified epoxy resin and a preparation method thereof, and belongs to the technical field of high polymer materials. The heat-resistant modified epoxy resin is prepared from the following components in parts by mass: 45 to 55 parts of matrix epoxy resin, 10 to 20 parts of methyl phenyl silicone resin, 8 to 12 parts of nano silicon dioxide, 0.8 to 2.0 parts of a silane coupling agent, 6 to 10 parts of a curing agent, 0.3 to 0.8 part of an accelerant, 15 to 30 parts of silica fume powder and 0.5 to 1.2 parts of an antioxidant. By introducing components such as methyl phenyl silicone resin and nano silicon dioxide with a specific particle size, and combining the synergistic effect of the silane coupling agent, the heat resistance of the epoxy resin is effectively improved; the antioxidant with a specific structure is used, and the performance retention rate of the modified epoxy resin under a thermo-oxidative aging condition is remarkably improved, so that the service life of the material is prolonged, and the long-term stability of the material in a high-temperature environment is enhanced.

The invention belongs to the technical field of ceramics, and particularly relates to a preparation method of an insulating ceramic material, which comprises the following steps: by taking bis (3-chloropropyl) dichlorosilane and 3-chloropropyl trichlorosilane as raw materials, spraying and depositing to obtain silicon porous particles, and stirring and permeating by utilizing aluminum isopropoxide to form silicon-aluminum composite particles; and finally, mixing aluminum isopropoxide, trichloromethylsilane and the silicon-aluminum composite particles, standing, heating and sintering to obtain the insulating ceramic material. The problem of brittleness of an existing aluminum oxide ceramic material is solved, a silicon porous material is utilized to form a porous structure, a silicon hydroxyl active system is provided, active connection and compactness with aluminum oxide are improved, the porous structure can form a frame structure which is through inside and outside, the internal toughness of the ceramic is improved, and the service life of the ceramic is prolonged. Therefore, the purpose of improving brittleness is achieved.

According to the veneer with the melamine decorative paper veneering and the preparation method, the veneer comprises a middle base material layer, high-density boards arranged on the upper face and the lower face of the middle base material layer and melamine softening paper arranged on the high-density boards in a hot-pressing mode, and the middle base material layer is a shaving board. A traditional three-layer composite technology is changed into a five-layer composite technology, the high-density board and the softened triamine paper are reserved after grooving, the brittleness and toughness of the materials are solved, the product bending yield is increased, and the problems of adhesive tape separation and color difference caused by uneven spraying of a softening agent and interference of the spraying amount can be solved by adopting the melamine softened paper.

This invention relates to the field of flame-retardant polymer materials technology, specifically a process for preparing high-temperature flame-retardant PC / ABS alloy resin modified with maleic anhydride-grafted POE. The modification of PC / ABS alloys to achieve high heat resistance and halogen-free flame retardancy often presents the technical challenge of synergistically improving heat resistance, toughness, and flame retardancy. This invention employs a synergistically optimized preparation process. A specific step-feeding melt-blending extrusion strategy is used, where PC and heat-resistant ABS, with maleic anhydride-grafted POE as the core compatibilizer, are melt-blended. After sufficient plasticization and the initial formation of a stable phase structure, a heat-sensitive halogen-free phosphorus-based flame retardant and an anti-dripping agent are injected. This avoids premature decomposition and failure of the flame retardant at high temperatures, ensures sufficient reaction of POE-g-MAH at the PC / ABS phase interface, optimizes the dispersed phase morphology, enhances the low-temperature impact toughness and stress cracking resistance of the PC / ABS alloy resin, and solves the material brittleness problem caused by the introduction of flame retardants.

The invention relates to the technical field of printing nickel screens, in particular to an acid and alkali resistant high-strength composite printing nickel screen and a preparation method thereof. The composite printing nickel screen comprises a printing nickel screen base body, and a nickel electroplating layer, a chromium electroplating layer and a photosensitive resin layer are sequentially arranged on the surface of the printing nickel screen base body from inside to outside. The photosensitive resin layer is prepared from a polyurethane-acrylate prepolymer and sulfydryl silicon resin through a sulfydryl-olefin click chemical reaction; the preparation method comprises the steps that S1, a core mold is put into a first nickel plating electroplating solution for nickel plating, a nickel net is separated from the core mold, and a printing nickel net base body is obtained; s2, the printing nickel net base body is put into a second nickel plating electroplating solution for nickel plating, and the surface of the printing nickel net base body is covered with an electroplated nickel layer; then plating chromium; and S3, preparing a photosensitive resin layer on the surface of the electroplated chromium layer. According to the invention, the strength, acid and alkali resistance and other properties of the printing nickel screen are comprehensively improved, the application problem of the traditional technology in a severe environment is solved, and a new technical path is provided for the high-performance printing nickel screen.

The invention discloses a high-strength low-resistivity conductive packaging material and a preparation method thereof, and relates to the technical field of packaging materials.The preparation method comprises the steps that firstly, zinc oxide nanorods are cleaned and dispersed in deionized water through ultrasonic concussion, urea is added for nitrogen doping treatment, and finally nitrogen-doped zinc oxide nanorods are obtained through cleaning and drying; secondly, polyacrylic acid is dissolved in deionized water, and a polyacrylic acid solution is obtained; and finally, mixing the nitrogen-doped zinc oxide nanorod with a polyacrylic acid solution, adding a dispersing agent sodium dodecyl benzene sulfonate, and ensuring uniform dispersion through ultrasonic oscillation and stirring. The nitrogen-doped zinc oxide nanorod is compounded with a polyacrylic acid matrix, so that the balance between conductivity and strength is remarkably improved, and the pressure resistance and tear resistance of the material are improved. Meanwhile, the dispersity and the conductivity of the zinc oxide nanorod are enhanced through nitrogen doping, the problem that a traditional material is poor in dispersity is solved, and the stability and the long-term use performance of the composite material are ensured.

This application discloses an adhesive for semiconductor packaging and its preparation method. The adhesive comprises the following raw materials in parts by weight: 100 parts epoxy resin, 1-5 parts curing agent, 0.1-1 parts accelerator, 10-20 parts silicone-modified polyurethane, 5-10 parts thermally conductive filler, 3-6 parts thickener, and 20-30 parts diluent. The silicone-modified polyurethane is prepared by hydrosilylation of an alkenyl polyurethane prepolymer and a siloxane compound in a mass ratio of 10:0.3-1. The alkenyl polyurethane prepolymer is obtained by polymerization of raw materials containing polyether polyol, alkenyl polyethylene glycol ether, and isocyanate. This application, by adding silicone polyurethane to the epoxy resin system, introduces flexible segments and forms an interpenetrating network structure, effectively compensating for the loss of flexibility in the epoxy adhesive layer and effectively solving the problem of flexibility degradation of epoxy resin encapsulants after filling with thermally conductive fillers.

The application discloses a kind of cyclic olefin multi-block copolymer and its preparation method and application, it includes the following steps: S1, solvent, cocatalyst, cyclic olefin, chain shuttle agent are mixed to obtain mixed solution;Add olefin again;S2, catalyst I and catalyst II are added in step S1 and carry out polymerization reaction, post-processing is obtained cyclic olefin multi-block copolymer;Wherein, the structural formula of catalyst I and catalyst II are as follows:Wherein, M is titanium, zirconium or hafnium;X is halogen, C 1～10 Alkyl of C 1～10 Alkoxy or C 1～10 Alkylamine;R1 And R2 It is independently selected from C 1～10 Aliphatic group, substituted or unsubstituted C 6～15 Aromatic group;R3, R4, R5 And R6 Selected from C 1～10 Alkyl or C 6～15 Aromatic group.The cyclic olefin multi-block copolymer prepared by selecting specific structure catalyst I and catalyst II has cyclic olefin / olefin chain soft segment (low T g1 ) with low insertion rate and cyclic olefin / olefin chain hard segment (high T g2 ) with high insertion rate;The obtained material can solve the brittleness problem of COC plastic, and also can obtain COC elastomer.

The invention provides a cycloolefin block copolymer and a preparation method thereof, and relates to the technical field of block copolymers, the preparation method comprises the following steps: sequentially adding monocycloolefin, cycloolefin containing a rigid structure, an inert solvent, a molecular weight regulator and a cocatalyst into a reaction kettle, and mixing to obtain a mixed solution, simultaneously adding a solution of a catalyst I and a catalyst II in an inert solvent, and carrying out ring-opening polymerization reaction; and after the reaction is finished, removing the catalyst I and the catalyst II, filtering to take supernatant liquid, introducing a hydrogen source into the supernatant liquid, adding a hydrogenation catalyst, carrying out hydrogenation reaction, and after the reaction is finished, filtering and separating to obtain the cycloolefin block copolymer. The cycloolefin block copolymer prepared by the invention has better thermal stability, higher elongation at break, higher glass transition temperature, good transparency and excellent processability.

The application discloses a strontium ferrite / polyether ether ketone composite magnet and a preparation method and application thereof, and belongs to the technical field of permanent magnet materials.The strontium ferrite / polyether ether ketone composite magnet comprises, in mass fraction, near Curie point magnetic field heat-treated strontium ferrite magnetic powder 84-95 parts, polyether ether ketone 5-15 parts, silane coupling agent 0.5-1.5 parts and lubricant 0.3-0.7 parts.The application adopts the above strontium ferrite / polyether ether ketone composite magnet and the preparation method and application thereof, realizes the synergistic improvement of magnetic performance, mechanical strength and heat resistance through intrinsic magnetic domain structure optimization, interface bonding strengthening and high densification structure design, and can meet the application requirements under the working conditions of high temperature, high reliability and high strength.

The invention discloses a polycarbonate material containing functionalized graphene and a preparation method of the polycarbonate material. The polycarbonate material comprises the following components in percentage by weight: 55-75% of polycarbonate, 5-10% of functionalized graphene, 3-7% of multi-walled carbon nanotubes, 3-8% of a flame retardant, 10-20% of an elastomer, 2-5% of a compatilizer, 0.5-2% of an antioxidant, 0.5-2% of an anti-dripping agent and 0.5-2.0% of a release agent. According to the preparation method, the polycarbonate material is obtained by mixing the raw materials through a pretreatment and step-by-step mixing method and a twin-screw extrusion method. The polycarbonate material containing functionalized graphene has the problems of insufficient thermal conductivity and poor flame retardance, and can meet the comprehensive requirements of the polycarbonate material in the aspects of mechanical properties, light weight and the like.

This invention relates to the field of waterborne coatings technology, specifically to a waterborne industrial anti-rust paint for steel components and its preparation method. This invention overcomes the problems of insufficient anti-rust performance and weak mechanical properties of existing waterborne industrial anti-rust paints. This invention achieves a synergistic effect of chemical anchoring and physical shielding by simultaneously bonding phosphate groups and graphene to the epoxy resin molecular chain; it significantly improves the mechanical properties of the coating film by using an organosilane coupling agent-modified waterborne polyamide curing agent to form an organic-inorganic interpenetrating network structure; it avoids the brittleness problem of pure epoxy systems by introducing a core-shell structured self-crosslinking acrylate emulsion, and the formed interpenetrating polymer network structure further enhances the density of the coating film; it forms an active-passive electrochemical synergistic protection with zinc-aluminum phosphate composite pigments by adding functionalized conductive polymer aqueous dispersions; and it enhances anti-rust performance by compounding zinc-aluminum phosphate composite pigments with glass powder.

The invention discloses a light-transmittance-variable heat-insulation shading plate and a preparation method thereof.The heat-insulation shading plate structurally comprises an organic glass layer, an aerogel layer and an organic glass layer, the aerogel layer is of a sandwich structure, first wet gel prepared from orthosilicate is arranged in the aerogel layer, and second wet gel is arranged in the aerogel layer; second wet gel is prepared from methyltriethoxysilane at the outer part; and methyl methacrylate is coated between the aerogel layer and the organic glass layer. The aerogel and the organic glass are compounded and complement each other under the condition of not influencing respective properties, so that the problem of poor heat insulation of the shading plate is solved, the light transmittance can be adjusted according to the environment temperature, heat insulation is further assisted, and the composite shading plate has a wide application prospect.

The present invention belongs to the field of refractory materials technology in the field of new materials for smelting or refining furnace linings of special steels such as clean steel, special steel, stainless steel, etc., and specifically relates to a hydration-resistant, corrosion-resistant low-carbon unburned magnesium calcium carbon brick and a manufacturing method thereof. The present invention can improve the hydration resistance of magnesium calcium carbon unburned bricks during mixing, pressing, heating and curing, storage, and transportation, and improve the corrosion resistance of magnesium calcium carbon products, thereby increasing the service life of the smelting furnace, reducing energy consumption, and achieving green production.

The invention provides SiC-ZrC ceramic fiber aerogel with high flexibility and low thermal conductivity and a preparation method of the SiC-ZrC ceramic fiber aerogel, and relates to the field of aerogel materials. The method comprises the following steps: preparing a spinning solution containing a silicon precursor, a zirconium precursor and polyvinylpyrrolidone, and carrying out electrostatic spinning, pre-oxidation and heat treatment to finish ceramic treatment of SiC and ZrC fibers in one step, so as to prepare SiC-ZrC ceramic fiber aerogel with a three-dimensional fiber network structure; the diameter of fibers in the aerogel is nanoscale, and the microstructure comprises a SiC nanofiber matrix and ZrC nanoparticles which are uniformly distributed. The SiC-ZrC ceramic fiber aerogel integrating excellent mechanical property and heat insulation property is finally prepared by regulating and controlling the content of the zirconium precursor, spinning parameters and heat treatment parameters and accurately controlling the fiber morphology and aerogel performance; the method is simple in process, good in controllability, high in repeatability and suitable for large-scale production.

The invention relates to the field of alloy treatment, and discloses a method for manufacturing ultrahigh wear-resistant hot work die steel, which comprises the following specific steps of: 1, preparing materials, namely selecting high-purity alloy powder according to the following specific proportion: 88.85% of iron, 0.45% of carbon, 5.00% of chromium, 2.00% of molybdenum, 0.80% of vanadium, 1.00% of nickel, 1.00% of tungsten, 0.50% of manganese and 0.40% of silicon, weighing the alloy elements according to the proportion, fully mixing, and preparing into alloy powder; according to the alloy powder compacting device, the evenly-mixed alloy powder is dried to remove moisture and other volatile substances in the powder, through mutual cooperation of the arranged box body, the multiple moving parts and the hydraulic part, and through intermittent upward movement of the push plate and intermittent splicing of the push plate, layer-by-layer compaction of the alloy powder is achieved. Due to the design, gaps among powder particles are effectively reduced, and tight combination and uniform distribution of the powder in the mold are ensured. And after the layer-by-layer compaction work is completed, looseness or displacement of the powder is avoided, and the compactness, the strength and the dimensional precision of the finished die steel are improved.

The application discloses a heat-insulating light-shielding plate with variable light transmittance and a preparation method thereof. The structure of the heat-insulating light-shielding plate is organic glass layer-aerogel layer-organic glass layer, wherein the aerogel layer is a sandwich structure, the inside of which is a first wet gel prepared from orthosilicate, and the outside of which is a second wet gel prepared from methyl triethoxysilane; and the aerogel layer and the organic glass layer are coated with methyl methacrylate. The application composites the aerogel and the organic glass, mutually supplements in the case of not affecting the respective performances, solves the problem that the heat insulation of the light-shielding plate is poor, and can adjust the light transmittance according to the environmental temperature, further assists heat insulation, and has a wide application prospect.

The invention discloses low-iron-loss non-oriented electrical steel for an electric vehicle motor and a processing method thereof, and relates to the technical field of non-oriented electrical steel, and the low-iron-loss non-oriented electrical steel comprises the following components in percentage by weight: 3.0-3.8% of Si, 0.25-0.35% of Als (% of Si), 0.40-0.55% of Mn (% of Si), less than or equal to 0.1% of P, less than or equal to 0.2% of N, less than or equal to 0.003% of C, less than or equal to 0.004% of C + Ti, less than or equal to 0.02% of S, and the balance of Fe and inevitable impurity elements. Through the gradient structure design of fine equiaxed grains on the surface layer and thick equiaxed grains on the core part, the high and low frequency working conditions of the electric vehicle driving motor are accurately matched. Under low frequency, the magnetic hysteresis loss is obviously reduced by coarse grains at the core part; under high frequency, surface layer fine grains improve resistivity by utilizing skin effect, eddy current loss is effectively inhibited, iron loss P1.5 / 50 is less than or equal to 2.35 W / kg, P1.0 / 400 is less than or equal to 14.00 W / kg, and P1.0 / 1000 is less than or equal to 38.0 W / kg, a cold rolling process adopts different-diameter rolling core design, and a gradient energy storage and grain structure can be formed through dynamic matching of the roller diameter of an upper working roller and the reduction rate of the current pass without additional nitriding and other complex processes.

The invention discloses a preparation method of isotropic polycrystalline bismuth telluride, which comprises the following steps: firstly, preparing a bismuth telluride alloyed powder raw material, ultrasonically vibrating, screening powder with specific granularity, putting into a drying oven for drying treatment, loading into a graphite mold, and transferring into a vacuum hot pressing furnace; and successively carrying out slow heating and pressurizing treatment, heat preservation and pressure maintaining treatment and heat preservation and pressure relief treatment, and carrying out furnace cooling to obtain the high-performance isotropic polycrystalline bismuth telluride block. The method provided by the invention makes up the defects of the existing bismuth telluride process and method for preparation, meets the urgent demand on the high-performance isotropic polycrystalline bismuth telluride thermoelectric material in fundamental research and application production, and avoids the brittleness problem caused by mechanical property difference in different directions after the bismuth telluride material is deformed; and the optimization of the thermoelectric performance and the uniform stability in all directions are realized, the manufacturing cost is greatly saved, and a good material preparation basis is provided for subsequent processes of scribing, pelletizing, packaging and the like of bismuth telluride.

This invention belongs to the technical field of covalent organic framework membrane materials, and provides a covalent organic framework / polyethersulfone hybrid matrix membrane, its preparation method, and its application. The method includes the following steps: mixing polyethersulfone, a solvent, and trialdehyde-based resorcinol to obtain a trialdehyde-based resorcinol solution; coating the trialdehyde-based resorcinol solution onto a glass fiber filter membrane to obtain a trialdehyde-based resorcinol / polyethersulfone membrane; mixing p-phenylenediamine, a catalyst, and water to obtain a p-phenylenediamine solution; and immersing the trialdehyde-based resorcinol / polyethersulfone membrane in the p-phenylenediamine solution to react, thereby obtaining the covalent organic framework / polyethersulfone hybrid matrix membrane. The preparation method of this invention is mild, and the resulting membrane is uniform and stable, fully combining the high flux of the polymer and the CO2 suppression capabilities of the covalent organic framework. 2 The advantages of strong adsorption separation significantly improve the H2O performance of covalent organic framework / polyethersulfone hybrid matrix membranes. 2 Flux and H 2 / CO 2 Selectivity.