2146 results about "Phenol formaldehyde resin" patented technology

The invention discloses an integrated preparation method of a SiC-based composite material environment barrier coating in the technical field of aviation thermal structure materials, which comprises the following steps: cleaning a substrate, carrying out vacuum impregnation of phenolic resin and curing, coating Si slurry to form a bonding layer, coating rare earth silicate slurry to form a barrier layer, and drying to obtain the SiC-based composite material environment barrier coating. And finally carrying out high-temperature heat treatment in an inert atmosphere. According to the method, through an integrated slurry coating and gradient curing process, the performance of a base body is protected, and meanwhile efficient preparation of the coating is achieved; by adopting an integrated slurry coating and gradient curing technology and combining with an optimized medium-temperature sintering process, the matrix performance is effectively protected while the compactness of the coating is ensured, the bonding strength and interface stability of the coating are improved through the design of the phenolic resin transition layer and the silicon bonding layer in cooperation with the rare earth silicate barrier layer, and the bonding strength of the coating is improved. And the coating shows excellent protection performance in a high-temperature corrosion environment.

The invention relates to the technical field of friction materials, and particularly discloses an electromagnetic brake friction material prepared from granules and a preparation process of the electromagnetic brake friction material in order to solve the problem that an existing electromagnetic brake friction plate is difficult to prepare or insufficient in performance. The reinforcing material comprises plasma modified aramid pulp, coupling modified composite mineral fibers, SiO2 coated tetrapod-like zinc oxide whiskers and carbon fiber-aluminum silicon whiskers; the filler comprises modified needle-like wollastonite and organic modified precipitated barium sulfate; the adhesive comprises boron-silicon synergistic modified phenolic resin and modified carboxy nitrile rubber. The raw materials are improved, and granules are prepared by adopting a mixing and crushing process, so that the content of an adhesive can be greatly reduced, meanwhile, the die filling efficiency can be improved, the die thickness and the high-temperature heat fading of the friction material can be reduced, a cold press molding process can be omitted, and the qualification rate of finished friction materials can be improved.

The invention relates to the technical field of phenolic resin production monitoring, and discloses a phenolic resin production abnormity monitoring method and system fused with machine learning. The method comprises the following steps: acquiring a real-time production data set, and identifying production environment parameters and the number of reaction stages; a normal monitoring model is set based on the parameters and the number, the relative position of the reaction stage is positioned, and an operation monitoring mode is determined by combining real-time data; then identifying a key reaction stage and a monitoring position, constructing a side parameter prediction network and setting an abnormity recovery rule; sensing the operation state of the equipment in combination with the operation monitoring mode and the exception recovery rule, and analyzing the environment change trend to set an exception sensing mode; identifying an abnormal production condition based on an abnormal perception mode, and combining a side parameter prediction network to set a single-stage de-trapping mechanism; and finally, performing exception monitoring processing according to an exception sensing mode, a single-stage de-trapping mechanism and an exception recovery rule to obtain a result.

A high-temperature-resistant and aging-resistant polyurethane material and a preparation method therefor. The polyurethane material comprises the following components in parts by mass: 21-27 parts of a modified polyurethane resin, 10-15 parts of a phenolic resin, 10-15 parts of an epoxy resin, 16-20 parts of a modified solid filler, 7-13 parts of a curing agent, 1-2 parts of a defoaming agent, 1-3 parts of a wetting agent, 0.7-1 part of a leveling agent, and 5-10 parts of water. The high-temperature-resistant and aging-resistant polyurethane material has excellent temperature resistance and moisture resistance, high aging resistance, and strong adhesion to a glass surface and can be used as a coating with which a glass surface is coated.

The invention provides a phenolic resin-based spherical silicon-carbon composite material as well as a preparation method and application thereof, and belongs to the technical field of lithium battery materials. The preparation method comprises the following steps: preparing spherical phenolic resin by adopting a suspension polymerization method, curing to obtain phenolic resin microspheres, preparing porous carbon spheres by taking the phenolic resin microspheres as a carbon precursor in a carbonization and alkali activation manner, carrying out CVD vapor deposition on nano silicon, and carrying out carbon coating to obtain the phenolic resin-based spherical silicon-carbon composite material. The phenolic resin is utilized to form a highly cross-linked network structure after curing, the carbon spheres obtained after carbonization have good mechanical strength and rigidity, the porous structure of the porous carbon spheres provides a volume change buffering structure for nano-silicon, the lithium ion path is shortened, the spherical structure is beneficial to uniform dispersion, nano-silicon particles are prevented from gathering, and the performance of the lithium ion battery is improved. And the porous carbon spheres with high specific surface area can also improve the interface reaction activity, so that the problems of high volume expansion, low conductivity and slow ion diffusivity of silicon are solved.

The invention belongs to the technical field of 3PE corrosion prevention, and particularly relates to a high-temperature-resistant and cathodic disbonding-resistant 3PE corrosion-resistant pipeline and a preparation method thereof. A pipeline epoxy bottom layer, a middle adhesive layer and a polyethylene surface layer are subjected to systematic chemical synergistic modification, specifically, the epoxy bottom layer is modified with phenolic resin and amino silane, and a heat-resistant compact barrier is formed; the middle layer reacts with maleic anhydride grafted polyethylene through amino silane to construct a chemical bridge for simultaneously connecting the upper layer and the lower layer; the surface layer is grafted with high-density polyethylene through fluoroprimary amine modified glycidyl methacrylate, and a hydrophobic and oleophobic chain and a reactive functional group are introduced; according to the structure, through the synergistic effect of the high-temperature stability of the bottom layer, the two-way chemical bridging capacity of the middle layer and the inert hydrophobic characteristic of the surface layer, the long-term use temperature upper limit, the stripping resistance and the medium infiltration resistance of the pipeline are improved, and a solution is provided for long-term protection of the pipeline in the severe environment.

The invention belongs to the field of battery negative electrode materials, and particularly relates to a sodium ion battery hard carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: mixing phenolic resin and asphalt, and carrying out pre-oxidation treatment to obtain a pre-oxidized precursor; and under a protective atmosphere, sequentially carrying out pre-carbonization treatment and carbonization treatment on the precursor subjected to the pre-oxidation treatment to obtain the sodium-ion battery hard carbon negative electrode material. In the pre-oxidation process, the asphalt and the phenolic resin are crosslinked, so that the foaming phenomenon of the phenolic resin in the subsequent carbonization process is reduced, the escape of small molecule gas in the phenolic resin is inhibited, the surface defects of the phenolic resin-based derived hard carbon material are further reduced, more closed pores are formed, and the sodium storage performance is improved. Meanwhile, a graphite-like carbon layer formed in the high-temperature carbonization process of the asphalt can be effectively inserted into a rigid framework of the phenolic resin hard carbon to construct a three-dimensional continuous conductive network, so that the electronic conductivity of the phenolic resin-based hard carbon is greatly improved, and the electrochemical performance of the sodium ion battery is improved.

The invention discloses an injection molding high-density alloy steel sintering integrated preparation process, which comprises the steps of alloy raw material proportioning, feed preparation, injection molding, continuous thermal desorption sintering treatment and enhanced heat treatment, and comprises the following steps: selecting gas atomization pure iron powder subjected to vacuum reduction treatment, and matching with chromium, nickel, molybdenum, vanadium, carbon, silicon, manganese and iron powder multi-component alloy proportioning; a phenolic resin-polyformaldehyde composite binder is adopted, 0.5-1.5% of a lubricating additive is added, internal mixing parameters are controlled under the protection of inert gas according to the powder-to-rubber ratio of 72-77%: 23-28%, and the problem that the compatibility of a single binder and alloy powder is poor is solved; three-section gradient temperature control injection molding and a continuous atmosphere furnace sectional degreasing-sintering integrated process are combined, and strengthening heat treatment is matched, so that sufficient diffusion of elements and densification of a green body are realized, and defects are avoided. The technology effectively solves the technical problems that traditional raw materials are high in impurity content and insufficient in element diffusion, and therefore the alloy steel sintering preparation efficiency can be improved.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to a preparation method of a graded ordered silicon-carbon negative electrode material for a lithium ion battery, which comprises the following steps: (S1) mixing phenolic resin and a template agent, calcining, and etching to obtain porous carbon containing macropores; (S2) carrying out cracking and carbon coating on the silicon source gas to obtain nano crystalline silicon containing a carbon coating layer; (S3) mixing the porous carbon with the nano crystalline silicon containing the carbon coating layer, and then carrying out ultrasonic vibration, so that macropores of the porous carbon are filled with the nano crystalline silicon to obtain a silicon-carbon composite material I; (S4) treating the silicon-carbon composite material I by using a carbon-containing sealing agent, and then activating to obtain a silicon-carbon composite material II; and (S5) carrying out vapor phase silicon deposition on the silicon-carbon composite material II to fill the amorphous silicon in the pores of the porous carbon, and then carrying out carbon coating to obtain the graded ordered silicon-carbon negative electrode material. The silicon-carbon negative electrode material prepared by the invention is of a composite structure in which crystalline silicon and amorphous silicon are spatially and orderly distributed, so that the structural stability and the uniform distribution of silicon are realized.

The application belongs to the technical field of functional resin, and particularly relates to a novel modified phenolic resin with high heat resistance, preparation and application thereof. The thermoplastic phenolic resin is modified by 4,4'-diaminodiphenyl methane (MDA) to improve the heat resistance of the phenolic resin. The obtained modified phenolic resin has excellent heat resistance, and when the modified phenolic resin is applied to a friction material as a binder, the wear rate of the friction material at high temperature is greatly reduced, and the service life of the friction material is prolonged.

The cBN resin superhard grinding wheel is prepared from the following raw materials in percentage by mass: 30 to 45 percent of cBN grinding material, 1 to 3 percent of nano yttrium oxide, 2 to 3 percent of nano zirconium oxide, 2 to 4 percent of coupling agent, 1 to 3 percent of silicon dioxide compound and the balance of phenolic resin. The phenolic resin matrix is jointly modified by the nano yttrium oxide, the nano zirconium oxide and the specific silicon dioxide compound, and the prepared grinding wheel has good wear resistance, hardness and temperature resistance.

The invention relates to the technical field of electronic packaging materials, in particular to a phthalonitrile modified thermosetting resin composition containing a siloxane structure and application of the phthalonitrile modified thermosetting resin composition in the electronic packaging materials. The composition comprises multifunctional epoxy resin, XYLOK phenolic resin, a curing accelerator, a modifier and an inorganic filler, and the modifying agent is eugenol phthalonitrile trisiloxane. The modifier disclosed by the invention has good mechanical compatibility and dispersity in matrix resin; when the epoxy resin is applied to a thermosetting resin system, the processability can be improved, and the toughness of a cured product can be effectively improved while the glass-transition temperature is increased, so that the cured product has excellent bending property; the composition has excellent thermal stability, low bending modulus, good impact performance and humidity and heat resistance after being cured, the glass transition temperature of the composition is effectively improved, the comprehensive performance of resin is remarkably improved, and the composition is suitable for improving the packaging reliability and environmental stability of semiconductor devices.

Provided is a heat-curable acrylic resin composition which is capable of suppressing the generation of ultra-fine bubbles when cured under heat and pressure, and which has excellent adhesiveness. A thermosetting acrylic resin composition which contains (A) an acrylic copolymer having a carboxyl group and (B) a phenolic resin, and which is characterized in that: when the acrylic copolymer (A) is an acrylic copolymer (A-1) having a glass transition temperature of-35 DEG C or less, the phenolic resin (B) is a phenolic resin; the thermosetting acrylic resin composition contains a specific content of an epoxy curing agent (C-1), contains a specific content of a novolac phenolic resin (B-1) or a self-crosslinking phenolic resin (B-2) as the phenolic resin (B), and contains a specific content of a novolac phenolic resin (B-1) or a self-crosslinking phenolic resin (B-2) when the novolac phenolic resin (B-1) is contained as the phenolic resin (B). The thermosetting acrylic resin composition also contains a specific content of an amine curing agent (C-2).

The invention relates to the technical field of refractory materials, in particular to an antioxidant and application thereof in steel ladle slag line bricks, and the antioxidant comprises a Si / SiC multiphase material, modified nano Al2O3 and CaF2; the ladle slag line brick comprises an antioxidant, fused magnesite, crystalline flake graphite and phenolic resin. Si-SiC compound waste is subjected to magnetic separation and acid pickling, then a SiO2 passivation layer is formed through pre-oxidation, moisture and air in the storage period are isolated, and a titanate coupling agent is introduced to improve the wettability and compatibility with phenolic resin. P2O5 released by phosphate on the surface of the modified nano Al2O3 at a high temperature reacts with alkali (earth) metal migrated to a SiO2 oxide layer to prevent the alkali (earth) metal from forming a low-melting-point eutectic substance, CaF2 reacts with SiO2 along with temperature rise, a passivation layer is broken, internal Si and SiC are directly exposed, and boron oxide of the modified nano Al2O3 remarkably reduces activation energy and a temperature threshold value of the reaction of CaF2 and SiO2.

The invention relates to the technical field of porous carbon materials, and discloses a preparation method of phenolic resin-based porous carbon based on synergistic activation of water vapor and carbon dioxide. The key point of the method is to construct a multi-dimensional process of'ZIF-8 (at) Ni-MOF derived bifunctional material pore forming-nitrogen / nickel co-doping + dynamic pressure-double-gas synergistic etching + Ti < 3 > C < 2 > T < x > MXene gradient modification '. The MOF derivative material provides regular initial pore channels and active sites, and precise customization of the pore diameter of 0.7-50 nm is realized by combining dual-gas characteristic complementation and dynamic pressure regulation and control; and MXene modification synchronously improves the conductivity and the interface bonding force. The micropore rate is greater than or equal to 88%, the specific surface area is greater than or equal to 2200m < 2 > / g, the total pore volume is greater than or equal to 1.3 cm < 3 > / g, and the process is free of chemical waste liquid pollution. When the material is applied to a lithium battery silicon-carbon negative electrode, the capacity retention rate after 500 cycles is greater than or equal to 85%, and the industrialization value is high.

The invention relates to the technical field of battery negative electrode materials, in particular to irregular spherical porous carbon and a preparation method and application thereof, and a silicon-carbon composite material and a preparation method and application thereof. The liquid phenolic resin is emulsified, compounded, cross-linked and cured under the condition of an oil-soluble and water-soluble compound emulsifier, meanwhile, the shape of the obtained resin is changed in an ultrasonic-assisted mode under the combined action of ultrasonic disturbance and different interfacial tensions, spherical resin is adjusted into irregular spherical resin, and the spherical resin is prepared into the irregular spherical resin. And performing pyrolysis and gas activation to obtain the irregular porous spherical carbon. Compared with spherical carbon, the irregular spherical carbon prepared by the invention has the advantages that on the premise of keeping the strength of the spherical carbon, the irregular spherical carbon can increase the contact area between carbon particles and a binder, and the carbon particles and the binder are not easy to separate, so that the cycling stability of a battery (especially a lithium ion battery) is improved.

The invention provides a treatment method for recovering high-purity graphite from black powder leaching residues. The treatment method comprises the following steps: removing impurity elements in graphite from the black powder leaching residues in a Joule heat flash evaporation manner; the black powder leaching residues obtained after impurity removal are put into a ball mill, liquid phenolic resin is added, full mixing is conducted, and ball milling is conducted; and putting the ball-milled mixture into flash evaporation Joule thermal equipment, and carbonizing and graphitizing the phenolic resin to obtain regenerated graphite. According to the method, the temperature of the black powder leaching residues can be increased within an extremely short time, metal impurities in the black powder leaching residues are gasified, and impurities in graphite are removed. Phenolic resin is used for carbonization and graphitization, generated disordered carbon can fill up particle cracks in waste graphite and internal lattice defects, a conductive network among graphite particles is established, a compact carbon layer is formed on the surface of graphite, and graphite structure transformation can also be induced in the step. The regenerated graphite obtained by the method is similar to commercial graphite in capacity and good in cycling stability.

The invention relates to the technical field of sodium ion batteries, and discloses plant tar phenolic resin in-situ modified asphalt and a method for preparing a hard carbon material by using the plant tar phenolic resin in-situ modified asphalt. The preparation process of the method comprises the following steps: (1) mixing and dispersing; (2) carrying out hydrothermal polymerization; and (3) high-temperature carbonization. The plant tar is used as a raw material, low-cost phenolic resin is prepared through a hydrothermal reaction, asphalt molecules are doped in situ in the synthesis process, the asphalt molecules participate in the cross-linking process, a more complex mixed polymer is formed, the graphitization process in the high-temperature carbonization process is inhibited, and the high-performance phenolic resin is prepared. And finally, the sodium ion battery negative electrode hard carbon material with excellent sodium storage capacity and good cycle performance is prepared. The raw materials are wide in source, the production cost of the hard carbon material is remarkably reduced, the method has a wide mass production prospect, and an economical and efficient technical scheme is provided for industrial application of the hard carbon material.

The invention relates to the technical field of sand mold casting, and particularly discloses a gradient exhaust sand mold for an aluminum alloy thin-walled workpiece and a preparation method thereof.The sand mold comprises a cavity surface layer (with the hardness ranging from 90 HB to 95 HB), a transition layer (with the hardness ranging from 80 HB to 70 HB and a back sand layer (with the hardness ranging from 60 HB to 65 HB) which are arranged from inside to outside, and microporous ceramic exhaust rods (with the diameter ranging from 0.3 mm to 0.8 mm and the distance ranging from 1 mm to 3 mm) are embedded in the cavity surface layer; the exhaust rod is composed of a mullite fiber matrix and a nanometer gamma-AlO coating, the porosity is 40-50%, and the exhaust rod penetrates through the back sand layer to form a directional exhaust network. The preparation method comprises the following steps: mixing sand layer by layer (the cavity layer contains 1.0-1.5% of phenolic resin, and the back sand layer contains 0.4-0.6% of resin and 4-6% of starch); when sand is filled to the position 1-3 mm away from the surface of the cavity, an exhaust rod is implanted (the positioning precision is + / -0.1 mm); gradient compaction is carried out (the high pressure of a cavity is 3.0-4.0 MPa, the vibration of a transition area is 20-30 Hz, and the back sand airflow is 0.1-0.2 MPa); and carrying out microwave curing (2.5 to 3.5 kW, 60 to 120 s). The defects of hot cracks and air holes of the thin-wall part (smaller than or equal to 5 mm) are overcome synchronously, and the casting yield is increased to 95% or above.

The invention relates to the technical field of preparation of porous carbon materials, in particular to a carbon material with an ultrahigh specific surface area and a preparation method and application thereof, and the preparation method comprises the following steps: ball-milling and mixing a carbon precursor and a chemical activator to obtain a homogeneous mixture; synchronously carbonizing and activating the homogeneous mixture to obtain a carbonized compound; washing and drying the carbonized compound to obtain a carbon material with an ultrahigh specific surface area; the carbon precursor is waste phenolic resin. The waste phenolic resin is efficiently converted into the high-specific-surface-area porous carbon material (super activated carbon) through ball-milling-assisted homogenization and a synchronous carbonization / activation process, and the method has remarkable advantages in the aspects of environmental protection, process efficiency, material performance, application value and the like, not only solves the problem of thermosetting resin recovery, but also improves the recovery efficiency of the thermosetting resin. And the waste resin is converted into a high-added-value carbon material, so that the development of circular economy is promoted, and the dual-carbon strategic target is met.

The invention belongs to the technical field of oil field drilling, and particularly relates to a preparation method of modified sulfonated phenolic resin for drilling fluid, and the modified sulfonated phenolic resin is prepared by chemically bonding a functional monomer simultaneously containing sulfonic acid anions and quaternary ammonium cations in a phenolic resin structure in a free radical polymerization mode. The quaternary ammonium cation group adsorbs negatively-charged clay particles, the adamantyl group can be adsorbed in hydrophobic areas of the clay particles through association, and the sulfonated phenolic resin can be quickly adsorbed on the surface of the clay in a double adsorption mode of hydrogen bonds and electrostatic attraction. Besides, a large number of sulfonic acid anions can form a compact solvation layer after hydration, and a compact coating film can be formed when phenolic resin is quickly adsorbed on the surface of clay, so that the clay is prevented from being in contact with water, the stability of clay particles is realized, a compact mud cake can be formed, and the prepared phenolic resin has good filtrate loss reduction performance.

The invention relates to the field of sealing materials, in particular to a butyl rubber sealing material and a preparation method thereof. Comprising the following components in parts by weight: 50-70 parts of butyl rubber, 30-50 parts of a brominated isobutylene-p-methylstyrene copolymer, 30-50 parts of carbon black, 8-12 parts of an alkyl phenolic resin vulcanizing agent, 3-5 parts of zinc oxide, 1-3 parts of stearic acid, 1-3 parts of an anti-aging agent and 5-10 parts of a plasticizer. The butyl rubber provides ideal air tightness and heat aging resistance, bromine atoms are introduced into the brominated isobutylene-p-methylstyrene copolymer, co-vulcanization with the butyl rubber is achieved, it is ensured that a uniform and stable co-crosslinking network can be formed between the two rubber molecules, and the service life of the rubber is prolonged. The alkyl phenolic resin vulcanizing agent can form a C-C bond with high bond energy with two rubber molecules, so that the thermal aging resistance of the butyl rubber sealing material is effectively improved, the compression set is reduced, and the butyl rubber sealing material with excellent performance is prepared.

The application relates to the technical field of packaging films, and discloses an antistatic plastic packaging film and a preparation process.The antistatic plastic packaging film comprises 100 parts by weight of polyethylene, 1-6 parts by weight of phenolic resin polyaniline antistatic agent and 0.2-0.3 parts by weight of an antioxidant.The dodecyl succinic anhydride esterified phenolic resin contains carboxyl groups, can be used as a protonic acid, is doped into polyaniline through an in-situ polymerization reaction, makes imine nitrogen atoms of the polyaniline protonate, forms a charged excited state polaron, and thus the conductivity of the polyaniline is improved, the resistance of the polyethylene is reduced, and the antistatic performance of the packaging film is improved.The dodecyl succinic anhydride esterified phenolic resin and the doped polyaniline have good compatibility with the polyethylene, have a certain reinforcing effect on the polyethylene, and make the film material have higher tensile strength and elongation at break.

The invention discloses an anti-oxidation and anti-scouring heat prevention and insulation composite material, a preparation method and application, and belongs to the technical field of high-temperature thermal protection materials. According to the method, a two-step in-situ modification method is adopted, hydrolyzed organosilane reacts with phenolic resin to prepare silicon modified phenolic resin, then the silicon modified phenolic resin is bonded with an organoboron compound to obtain boron-silicon co-modified phenolic resin, a curing agent is added, then the boron-silicon co-modified phenolic resin is injected into a fiber reinforcement mold, and a finished product is obtained through a sol-gel reaction and normal-pressure drying. According to the invention, boron and silicon elements are embedded into phenolic aldehyde molecular chains through covalent bonds to form a boron-silicon-carbon hybrid network, a nano ceramic phase and a compact glassy protective layer are generated at high temperature, and the coating has excellent anti-scouring property, thermal stability and heat insulation property. The preparation process is simple and controllable, is suitable for large-scale production, can accurately regulate and control the performance, and is suitable for thermal protection parts of supersonic aircrafts.

The invention relates to the technical field of electronic packaging materials, in particular to a thermosetting resin composition for packaging a high-reliability semiconductor device. The composition comprises multifunctional epoxy resin, XYLOK phenolic resin, a curing accelerator, a modifier and an inorganic filler, and the modifying agent is eugenol phthalonitrile polysiloxane. The modifier has good mechanical compatibility and dispersity in matrix resin; and when being applied to a thermosetting resin system, the epoxy resin can improve the processability and effectively enhance the toughness of a cured product. The composition provided by the invention accords with the processing and forming process of the existing epoxy molding compound; according to the present invention, the spiral flow length of the molding compound is substantially increased, the processing performance is good, the cured product has advantages of good thermal stability, low bending modulus, good impact property and good heat and humidity resistance, and the glass transition temperature is increased. The resin is significantly improved in comprehensive performance, and is suitable for packaging semiconductor devices with high requirements on reliability and environmental stability.

The invention discloses high-compaction-density modified spherical lithium iron phosphate and a preparation method and application thereof.The preparation method comprises the steps that a composite iron source precursor and modified phenolic resin are compounded to form a spherical inner core, and then the spherical inner core is coated with a lithium-phosphorus mixed layer to construct a core-shell structure; the modified spherical lithium iron phosphate with the characteristics of'spherical core-porous shell 'is prepared by introducing boron nitride nanosheets as a structure-directing agent and a doping source and combining a dynamic gradient sintering process, and the modified phenolic resin is obtained by grafting water-soluble phenolic resin and polyethylene glycol, and the solid content of the modified phenolic resin is greater than or equal to 50%. The modified lithium iron phosphate with the compaction density larger than or equal to 2.55 g / cm < 3 > and the capacity retention ratio larger than 92.0% after 1C circulation 2000 times is prepared, and the technical bottlenecks that doping is not uniform, morphology is out of control and the compaction density is low in a traditional process are solved.

The invention belongs to the technical field of porous tantalum carbide ceramic preparation, and particularly relates to a preparation method of porous tantalum carbide ceramic based on a broken framework, which comprises the following steps: S1, preparing dipping slurry; s2, a polyurethane foam template is immersed in the dipping slurry, the polyurethane foam template is fully pressed so that the holes can be filled with the slurry, and the template is repeatedly rolled through a roller till no slurry flows out of the template; s3, drying the impregnated template, performing high-temperature treatment on the dried template, and cooling to room temperature to obtain a porous tantalum carbide framework; s4, crushing the porous tantalum carbide skeleton into a crushed skeleton with the size of 0.1-5 mm; s5, preparing a phenolic resin solution, mixing the crushed framework with the phenolic resin solution, then transferring the mixture into a mold, and forming after applying a certain pressure to obtain a porous tantalum carbide green body; the crushing brackets are stacked and spliced together to form a porous structure, the pores of a finished product can be adjusted by changing the sizes of the crushing brackets, and the crushing bracket can be applied to finer pores and is extremely low in shrinkage rate.

The invention relates to the technical field of refractory materials, and provides a composite regenerated magnesia carbon brick and a preparation method thereof. The composite regenerated magnesia carbon brick is prepared from the following raw material components in parts by mass: 55 to 65 parts of waste magnesia carbon brick, 40 to 50 parts of fused magnesia, 7 to 10 parts of composite graphite, 3 to 5 parts of antioxidant and 4 to 7 parts of phenolic resin, the composite graphite is of a core-shell structure, and a core in the core-shell structure is magnesium oxide coated graphite; and the shell in the core-shell structure is 1, 3, 5-trimethoxybenzene. According to the technical scheme, the problem that the mechanical property of the composite regenerated magnesia carbon brick is poorer due to poorer wettability of phenolic resin on graphite in related technologies is solved.

The invention relates to the technical field of refractory materials, in particular to a method for producing magnesia carbon bricks from low-carbon reduced magnesia. The method comprises the following steps: respectively weighing 80-90 parts by weight of magnesia, 3-5 parts by weight of a function enhancer, 1-3 parts by weight of aluminum powder, 0.3-1 part by weight of aluminum nitride, 2-3 parts by weight of carbon black, 3-5 parts by weight of crystalline flake graphite and 3-5 parts by weight of phenolic resin for later use; mixing the magnesite except the fine magnesite with phenolic resin, uniformly mixing, adding the rest raw materials, uniformly stirring at a low speed, adding the fine magnesite, and uniformly stirring at a high speed to obtain mixed slurry; and injecting the mixed slurry into a prepared mold, and sequentially carrying out compression molding and heat treatment to obtain the magnesia carbon brick. The magnesia carbon brick produced by the invention not only has excellent mechanical properties, but also has excellent thermal shock resistance stability and oxidation resistance; the quality of the produced magnesia carbon brick is effectively guaranteed, and meanwhile the service life of the magnesia carbon brick is prolonged to a certain degree.

The invention discloses a phenolic resin material as well as a preparation method and application thereof in 3D printing, and relates to the technical field of high polymer materials. When the phenolic resin material is prepared, hydroxylated carbon nanotubes react with isocyanate propyl triethoxy silane to prepare pre-modified carbon nanotubes, and then the pre-modified carbon nanotubes react with 2-chloroethyl triethoxy silane to prepare modified carbon nanotubes; the preparation method comprises the following steps: reacting vanillin with 5-amino-1, 2-dihydro-2-methyl-3H-1, 2, 4-triazole-3-thioketone and 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in sequence, so as to obtain pre-modified vanillin; reacting the pre-modified vanillin with divinyl disulfide to obtain modified vanillin; the modified vanillin, phenol and formaldehyde react to prepare modified phenolic resin, and then the modified phenolic resin reacts with the modified carbon nanotubes to prepare the phenolic resin material. The phenolic resin material prepared by the invention has good flame retardance, heat resistance, aging resistance, self-repairing property and mechanical property.