460 results about "Polyoxymethylene" patented technology

The invention relates to a preparation method of a geopolymer composite material based on modified fiber, which comprises the following steps: S1, fiber pretreatment: the fiber is one of basalt fiber and polyformaldehyde fiber; s2, performing surface roughening treatment on the fibers through a polyvinyl alcohol modified impregnating compound to obtain roughened fibers; s3, the roughened fibers are subjected to surface functional modification treatment through a functional modified impregnating compound, and functional modified fibers are prepared; s4, uniformly mixing the powder and an expanding agent according to a mass ratio, and adding an alkali activator solution and the functional modified fibers to prepare a geopolymer gel material; s5, the geopolymer gel material is subjected to stirring, mold filling, steam curing forming, demolding and continuous curing, and the geopolymer composite material based on the modified fiber is obtained.According to the preparation method, the geopolymer composite material with high strength and excellent crack resistance and toughness is obtained through alkali excitation, and the problems that geopolymers are low in toughness and large in brittleness are effectively solved.

In order to solve the problems of low yield, complex process and difficulty in purification in the existing preparation method of benzodifurandione, the invention provides a preparation method of benzodifurandione, which comprises the following operation steps: synthesis of benzodifurandione: mixing hydroquinone, paraformaldehyde, a transition metal catalyst and a ligand under an acidic condition to obtain a mixture A; introducing CO, reacting at the temperature of 120-150 DEG C to obtain a mixture containing benzodifuran diketone, cooling and filtering to obtain a benzodifuran diketone solid; and purification: purifying the benzodifuran diketone solid to obtain the benzodifuran diketone. The preparation method provided by the invention is simple and convenient to operate, the obtained monomer benzodifuran diketone raw material is high in purity and stable in quality, and large-scale production of polymers can be realized.

The invention relates to the technical field of metal powder injection molding, in particular to an MIM titanium alloy binder and application of the MIM titanium alloy binder to preparation of high-plasticity TC4 parts. The MIM titanium alloy binder comprises polyformaldehyde, aluminum stearate, polyethylene, queen bee wax and high-density polyethylene. According to the MIM titanium alloy binder, polyformaldehyde serves as a main component, high-melting-point bee wax and aluminum stearate are introduced, the bee wax can improve the thermal stability of a lubricant, aluminum stearate can inhibit volatilization of Al element, the rheological property and sintering behavior of feeding are remarkably optimized, the number of titanium alloy feeding cycles and the density after sintering can be increased, and the O content can be reduced.

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 relates to a high-temperature-resistant low-dielectric high-strength benzoxazine intermediate and a preparation method of benzoxazine, and belongs to the field of functional polymer materials. The method comprises the following steps: adding paraformaldehyde, unsaturated bond-containing dihydric phenol, a monohydric phenol compound and a diamine compound into a reactor, adding a solvent, reacting at 85-110 DEG C for 8-12 hours, after the reaction is finished, obtaining a benzoxazine intermediate through a purification process, and fully drying the benzoxazine intermediate for later use; and reacting the benzoxazine intermediate at 120-230 DEG C for 8-20 hours to obtain the polybenzoxazine resin.

The invention discloses a method for preparing a high-precision aluminum alloy part based on injection molding, which is characterized in that a modifier is added into a polyformaldehyde (POM)-based binder, so that the compatibility of the polyformaldehyde (POM)-based binder and aluminum alloy powder can be effectively improved, and after the polyformaldehyde (POM)-based binder is mixed with the aluminum alloy powder, the powder distribution is more uniform, and the strength of the aluminum alloy part is improved. The compactness and the structural strength of the injection molding aluminum alloy part are further improved; by adding ethylene bis stearamide, polyesteramide and stearic acid, the interface relationship between the powder and the binder can be improved, intermolecular or intramolecular interaction between the powder and the binder is promoted, the compatibility between the powder and the binder is improved, gaps are fully filled with the binder, the powder is wrapped with the binder, the friction force between the powder is remarkably reduced, and the service life of the binder is prolonged. Further, the viscosity of the whole feed is reduced; the raw materials with the double-peak granularity have higher flowability, the powder and the binder are uniformly distributed, and the material is more suitable for mold filling.

The invention discloses an application of an ionic liquid in extraction of trioxymethylene, in the process of generating trioxymethylene by acid-catalyzed condensation of a formaldehyde aqueous solution, the ionic liquid is added as an extraction agent to extract and separate the trioxymethylene generated by reaction, and the ionic liquid is methyl tributyl phosphonium bis (trifluoromethanesulfonyl) imide salt; when the ionic liquid is used for extracting trioxymethylene, a ternary azeotropic system of trioxymethylene, water and methylene glycol can be broken, the ionic liquid and trioxymethylene are subjected to nonpolar Van der Waals' force interaction so as to realize extraction, and methylene glycol and water are left in a water phase through hydrogen-bond interaction, so that high-purity trioxymethylene with the purity of more than or equal to 99.5 wt.% is obtained.

The invention discloses piperonyl butoxide and a preparation method thereof. The preparation method comprises the following steps: carrying out mixing reaction on dihydrosassafras oil, acetyl chloride and trioxymethylene in the presence of concentrated hydrochloric acid; after the reaction is finished, chloromethyl material reaction liquid is obtained; mixing and reacting the chloromethyl material reaction liquid with sodium hydroxide and diethylene glycol monobutyl ether to obtain a product containing piperonyl butoxide. According to the preparation method of piperonyl butoxide, the dihydrosassafras oil, acetyl chloride and trioxymethylene are subjected to chloromethylation reaction in the presence of a small amount of concentrated hydrochloric acid, so that the use of a large amount of concentrated hydrochloric acid in the traditional process is avoided, and the problem of waste acid generated in the chloromethylation reaction process is solved; and meanwhile, the content of piperonyl butoxide in the product can be increased, and the content of piperonyl butoxide is ensured to be greater than 98%.

The invention discloses a triazine desulfurizer and a preparation method thereof, and belongs to the technical field of gas purification. The triazine desulfurizer is mainly prepared from the following raw materials in percentage by weight: 20 to 50 weight percent of triazine derivative, 10 to 15 weight percent of sterically hindered amine, 3 to 7 weight percent of stabilizer, 1 to 3 weight percent of synergist, 0.5 to 1.5 weight percent of penetrant, 0.5 to 1.5 weight percent of inhibitor, 1 to 2 weight percent of additive and the balance of water, the preparation method of the triazine derivative comprises the following steps: adding 2-(diphenylphosphino) ethylamine into a toluene solvent, adding a paraformaldehyde aqueous solution in batches under a stirring condition, and reacting for 2-8 hours to obtain the triazine derivative. According to the triazine desulfurizer and the preparation method thereof provided by the invention, the triazine derivative and the sterically hindered amine are taken as a host, and the stabilizer, the synergist, the penetrant, the inhibitor and the assistant are compounded, so that the scaling trend of the triazine desulfurizer in an oil and gas well can be slowed down, the dissolution rate of hydrogen sulfide and the mass transfer rate in a solution are increased, and the desulfurization reaction is promoted; the desulfurization effect and the desulfurization rate are improved, and meanwhile, a very good scale inhibition effect is also achieved.

The invention discloses a strong acid and alkali resistant plastic material for fume hood surface decoration and a preparation method of the strong acid and alkali resistant plastic material, belongs to the technical field of plastic material processing, and aims at solving the technical problem that in the prior art, the acid and alkali resistance and the bending modulus of a plastic material for fume hood surface decoration need to be further improved. The preparation method specifically comprises the following steps: stirring amino-modified fluorosilicone resin, paraformaldehyde and 1, 4-dioxane in a reaction kettle, dropwise adding an anacardol solution, heating the reaction kettle to 85-95 DEG C, carrying out heat preservation reaction for 6-8 hours, and carrying out post-treatment to obtain the anacardol-based benzoxazine resin. Perfluoro-modified polysiloxane benzoxazine is prepared, naphthalene-containing epoxy resin and imidazole-modified silicon carbide microspheres are compounded, in-situ catalysis synergistic curing is carried out by using filler interface imidazole, a compact organic-inorganic hybrid interpenetrating network is constructed, and the strong acid and alkali corrosion resistance and bending modulus of the material are remarkably improved.

The invention belongs to the technical field of metal materials, and particularly relates to a high-strength decorative aluminum product metal material and a preparation method thereof. The preparation method of the high-strength decorative aluminum product metal material comprises the following steps: (1) adding carbon nano onions, sulfuric acid and oxalic acid into water to prepare a mixed acid solution, immersing an aluminum matrix into the mixed acid solution for anodic oxidation, and then cleaning and drying to prepare a pretreated aluminum matrix; and (2) polyformaldehyde fibers are added into the dispersion liquid, a heating reaction is conducted, a mixed solution is obtained, the surface of a pretreated aluminum matrix is coated with the mixed solution, then heat treatment is conducted, after aging is conducted at the room temperature, cleaning and drying are conducted, and the high-strength decorative aluminum product metal material is obtained. The preparation process is simple, the product performance is stable, and the product has the properties of high strength, high hardness, wear resistance, super-hydrophobicity, self-cleaning and the like.

The invention relates to the technical field of polyurethane, and discloses a high-strength impact-resistant TPU composite material and a preparation method, the high-strength impact-resistant TPU composite material comprises 60-85 parts by weight of polyurethane resin, 15-40 parts by weight of polyformaldehyde, and 1-4 parts by weight of hydroxyl polyurethane; the hydroxyl polyurethane is similar to a molecular main chain of polyurethane resin, a side chain contains hydroxyl, and the hydroxyl polyurethane and an ether bond of polyformaldehyde are subjected to hydrogen-bond interaction, so that the hydroxyl polyurethane plays a role in compatibilizing the polyurethane resin and the polyformaldehyde, the compatibility between the polyurethane resin and the polyformaldehyde is remarkably improved, and an alloy system with better mechanical properties is formed; the TPU composite material has higher tensile strength and keeps good impact strength; hydroxyl polyurethane contains a fused ring structure with high-temperature resistance and is not prone to thermal decomposition, the heat resistance of the TPU composite material is improved, and the initial thermal decomposition temperature is increased.

The invention provides a binder system for beryllium-titanium alloy powder injection molding and application, and relates to the technical field of metal powder injection molding. The adhesive system consists of the following components in percentage by weight: 76 to 84 percent of polyformaldehyde, 7 to 9 percent of high-density polyethylene, 5 to 7 percent of ethylene-vinyl acetate copolymer, 3 to 5 percent of paraffin, 0.1 to 0.5 percent of stearic acid, 0.1 to 1.5 percent of polyethylene glycol and 0.1 to 1 percent of BASF antioxidant. The feed preparation method based on the system comprises the steps of powder pretreatment, binder preparation, banburying mixing and cooling granulation, and uniform coating and dispersion of beryllium-titanium powder can be achieved. According to the system, the problems that in beryllium-titanium alloy injection molding, powder is prone to oxidation, poor in fluidity and low in size precision are solved, the viscosity of the prepared feed at 180 DEG C is 88-101 Pa.S, and the oxygen content is smaller than or equal to 0.24 wt%; the relative density of a finished product is larger than or equal to 96.5%, the size precision is + / -1% / in-+ / -2% / in, and the method is suitable for industrial production of beryllium-titanium alloy complex parts in the fields of spaceflight and nuclear energy.

The invention provides a composite solid electrolyte, a preparation method thereof and a battery, the composite solid electrolyte comprises a lithium salt, polyformaldehyde, a plasticizer and an inorganic filler, and the mass ratio of the plasticizer to the polyformaldehyde is 1: 50-1: 4. When the plasticizer accounts for a relatively small amount, crystallization of polyformaldehyde cannot be effectively inhibited, and the ionic conductivity of the composite solid electrolyte is relatively low; and when the plasticizer accounts for a large amount, the mechanical property of the electrolyte is poor. Therefore, the ionic conductivity of the polyformaldehyde-based electrolyte can be improved by a proper amount of plasticizer, and meanwhile, the electrolyte keeps good mechanical properties. The room-temperature ionic conductivity of the polyformaldehyde-based composite solid electrolyte provided by the invention can reach 1.43 mS / cm.

The invention discloses a phosphorus-nitrogen synergistic flame-retardant benzoxazine / epoxy resin composite material and a preparation method thereof. Firstly, a phenolic compound and DOPO react to generate an intermediate product, and then the intermediate product, an amine compound and paraformaldehyde are subjected to a dehydration condensation reaction to generate the phosphorus-nitrogen synergistic flame retardant benzoxazine. The phosphorus-nitrogen synergistic flame-retardant benzoxazine is added into epoxy resin for thermocuring to obtain the composite material. The prepared benzoxazine flame retardant contains phosphorus and nitrogen elements, the nitrogen-based flame retardant has the advantages of low pollution, low smoke, good compatibility with EP and the like, and a quenching effect, a dilution effect and a carbon layer barrier effect can be generated in the combustion process to prevent further combustion of flames. The composite material has better flame retardant property, can effectively reduce the risk of fire hazard caused by overheating or short circuit of equipment, and ensures the safe and stable operation of energy equipment.

The invention provides a polyformaldehyde-based metal injection molding feed as well as a preparation method and application thereof, and the polyformaldehyde-based metal injection molding feed comprises the following components in percentage by mass: 87-97% of metal powder and 3-13% of a binder, the metal powder comprises tungsten powder; the tungsten powder comprises first tungsten powder and second tungsten powder; the average particle size of the first tungsten powder is larger than that of the second tungsten powder; the binder comprises polyformaldehyde, a skeleton unit and a formaldehyde inhibitor. In the invention, the polyformaldehyde-based metal injection molding feed has good fluidity, stability and sintering performance, can be recycled for multiple times, is beneficial to improving the strength and degreasing efficiency of an injection blank, can reduce the production cost and energy consumption, and can obtain a product with better performance.

The invention discloses a nanofiber reinforced polyformaldehyde composite material and a preparation method thereof. The nanofiber reinforced polyformaldehyde composite material comprises the following raw material components in percentage by mass: 55-74% of a polyformaldehyde matrix; 11%-19% of polyketone resin; 5%-10% of a sulfur-free vulcanized elastomer; 8%-15% of a modified compound; 1%-3% of a silver nanowire; the invention relates to the technical field of composite materials. According to the nanofiber reinforced polyformaldehyde composite material and the preparation method thereof, the compound fibers provide an adhesion carrier for the boron nitride nanosheets, the strength of the composite material is improved, a heat conduction network is formed, the composite material has good flame retardance and heat conductivity, the continuity of the heat conduction network is guaranteed in cooperation with the silver nanowires, and the heat dissipation capacity of the composite material is improved; by combining the sulfur-free vulcanized elastomer and the polyketone resin, the elasticity and toughness of the composite material are improved, the notch impact strength is improved, the nanofibers are oriented in an electric field orientation mode, and the tensile strength and bending strength of the composite material are further improved.

The invention discloses fireproof flame-retardant phenolic resin and a preparation method thereof, and relates to the technical field of high polymer materials. When the fireproof flame-retardant phenolic resin is prepared, firstly, alkali lignin is depolymerized in a lithium bromide solution, and depolymerized lignin is prepared; carrying out multi-component reaction on the depolymerized lignin, amino-terminated polydimethylsiloxane, isonitrile diethyl methylphosphate and glacial acetic acid to prepare modified lignin; the preparation method comprises the following steps: carrying out reaction modification on montmorillonite and diisocyanate to prepare isocyanate modified montmorillonite; the isocyanate modified montmorillonite and 3-aminopropyltriethoxysilane are subjected to a reaction, and modified montmorillonite is prepared; and polymerizing phenol with the modified lignin, paraformaldehyde and modified montmorillonite, and discharging to obtain the fireproof flame-retardant phenolic resin. The prepared fireproof flame-retardant phenolic resin has the advantages of flame retardance, good toughness, high strength and aging resistance.

The invention discloses semi-aromatic nylon and a preparation method thereof, and belongs to the technical field of polyamide materials, the method comprises the following steps: adding calcium carbonate, a coupling agent and polyformaldehyde foam, and mixing to obtain pretreated calcium carbonate; the pretreated calcium carbonate, bio-based 2, 5-bis (aminomethyl) furan, bio-based isophthalic acid and an acid catalyst are mixed for polymerization, and a polymerization melt is obtained; performing post-treatment to obtain semi-aromatic nylon; the nylon prepared by adopting the formula and the method disclosed by the invention has the rigidity of wholly aromatic nylon and the toughness of semi-aromatic nylon, and is mild in synthesis condition and low in energy consumption; the addition of the polyformaldehyde foam can reduce the use amount of the coupling agent, reduce the addition of the auxiliary agent and improve the performance of the nylon material, and the polyformaldehyde foam gasifies and escapes from the system after assisting the uniform dispersion of the calcium carbonate, so that the introduction of the auxiliary agent is further reduced; the nylon can be applied to the fields of automobiles, electronics, ocean engineering or aerospace and the like.

A dematerialized information handling system display stand supports a display assembly with vertical adjustments using a single injection molded polyoxymethylene (POM) sliding member inserted in an extruded aluminum riser. A compression spring locks the sliding member in place with torsional force that releases to enable vertical movement. A hinge member couples to the sliding member to accept a display support that extends out of the riser and couples to the display assembly. Vertical sliding movement is provided with an assembly that uses only one screw for ease of assembly and disassembly.

The invention discloses a polyphenyl ether modified epoxy resin-based copper-clad plate, and particularly relates to the technical field of copper-clad plates, the polyphenyl ether modified epoxy resin-based copper-clad plate comprises a glue solution, an electronic glass fabric and a copper foil, and the glue solution comprises the following raw materials: modified polyphenyl ether, an inorganic filler, a curing agent, a flame retardant and the balance of epoxy resin. The bisphenol A epoxy resin, toluene and benzoyl peroxide are utilized to treat polyphenyl ether, the molecular weight of the polyphenyl ether can be reduced, the crosslinking property of the polyphenyl ether and the epoxy resin is better, then paraformaldehyde is utilized to catalyze and modify the polyphenyl ether, the terminal of the polyphenyl ether is grafted with hydroxymethyl, and the polyphenyl ether is grafted with polyphenyl ether. The compatibility and interface bonding force of the obtained hydroxymethylated polyphenyl ether and epoxy resin are good, the dielectric loss performance and toughness of the copper-clad plate can be effectively improved, and anhydrous aluminum silicate of an amorphous layered gap structure formed through specific activation treatment can be formed during temperature-controlled calcination of kaolin. The dielectric constant and the dielectric loss of the copper-clad plate can be obviously reduced.

The invention discloses quick heat-conducting precoated sand and a preparation process thereof, and relates to the technical field of precoated sand, the quick heat-conducting precoated sand comprises the following raw materials by weight: 100-105 parts of crude sand, 6-8 parts of a modified resin prepolymer, 2-4 parts of modified POE, 3.5-4.5 parts of a lubricant, and 3-5 parts of nano silicon nitride. The modified POE has a relatively strong high-temperature toughening effect on the modified resin prepolymer, can also form chemical crosslinking with the modified resin prepolymer, and has relatively strong compatibility with other raw materials in the precoated sand. The modified resin prepolymer is obtained by heating and ring-opening polymerization of a benzoxazine monomer obtained by reaction of 5-nitrosalicylaldehyde, 2, 4-bis (trifluoromethyl)-5-pyrimidinyl ethyl formate, paraformaldehyde, furfuryl amine and the like, the curing temperature of the modified resin prepolymer is reduced, the thermal stability is improved, and improvement of the high temperature resistance of the precoated sand is facilitated.

The invention relates to anti-corrosion micro-expansion self-compacting concrete for a steel pipe pile. Each cubic meter of the concrete is prepared from the following components in parts by mass: 250 to 300 parts of cement, 100 to 120 parts of recycled micro powder, 800 to 830 parts of recycled fine aggregate, 940 to 980 parts of recycled coarse aggregate, 20 to 32 parts of expanding agent, 0.15 to 0.25 part of graphene oxide, 4 to 6 parts of glass fiber, 1.5 to 4 parts of polyformaldehyde fiber, 10 to 13 parts of water reducing agent and 150 to 170 parts of water. The anti-corrosion micro-expansion self-compacting concrete has anti-corrosion, micro-expansion and self-compacting properties, can be suitable for underwater steel pipe pile construction, and remarkably improves the service life and reliability of the steel pipe pile in ocean and water-rich environments.

The invention relates to polyformaldehyde fiber concrete based on a stud area of a steel box girder, and belongs to the technical field of building materials. The polyformaldehyde fiber concrete comprises the following components in parts by weight: 400-550 parts of cement; 80 to 180 parts of water; 1000 to 1100 parts of coarse aggregate; 700 to 780 parts of fine aggregate; the surface of the calcium sulfate whisker is coated with a silane coupling agent. The polyformaldehyde fibers and the calcium sulfate whiskers are added into the concrete at the same time, the calcium sulfate whiskers are doped to provide a framework support for the concrete, after the calcium sulfate whiskers are wrapped by the cement paste, the calcium sulfate whiskers and other materials jointly form a three-dimensional supporting structure, and concrete pores can be filled with part of the whiskers, so that the compactness and compressive strength of the concrete are enhanced. The polyformaldehyde fibers are added, so that stress can be effectively dispersed, when the concrete is pressed, the polyformaldehyde fibers and a cement matrix bear loads together, the stress concentration phenomenon is reduced, and the compressive strength of the concrete is further improved.

The invention provides a treatment device and a treatment method for formaldehyde-containing wastewater. The treatment device comprises an adjusting unit, a degradation pretreatment unit and an anaerobic membrane biological reaction unit, the anaerobic membrane biological reaction unit comprises an anaerobic digestion sludge reaction zone, a membrane separation zone and a reconnection piece, the anaerobic digestion sludge reaction zone is communicated with the membrane separation zone, one end of the reconnection piece is communicated with the membrane separation zone, and the other end of the reconnection piece is communicated with the anaerobic digestion sludge reaction zone. The method can effectively remove formaldehyde, COD and other pollutants in the polyformaldehyde wastewater, effectively resists to-be-treated wastewater pollutant concentration fluctuation and violent water quantity and water quality impact, and has the advantages of low sludge yield, stable treatment and up-to-standard effluent quality.

The invention provides a beryllium-titanium alloy injection molding feed and a preparation method thereof, and relates to the technical field of metal injection molding. The beryllium-titanium alloy injection molding feed is prepared by mixing composite beryllium-titanium alloy powder and a catalytic degreasing binder according to the mass ratio of (70-80): (20-30), the composite beryllium-titanium alloy powder is composed of, by mass, 40% of spherical beryllium powder, 30% of spherical titanium powder and 30% of irregular beryllium powder. The D90 of the spherical beryllium powder and the spherical titanium powder is 60-80 [mu] m, and the D90 of the irregular beryllium powder is 6-10 [mu] m; the catalytic degreasing binder is prepared from the following components in parts by mass: 76 to 84 parts of polyformaldehyde, 7 to 9 parts of high-density polyethylene, 5 to 7 parts of ethylene-vinyl acetate copolymer, 3 to 5 parts of paraffin, 0.1 to 1.5 parts of stearic acid, 0.1 to 1.5 parts of polyethylene glycol and 0.1 to 1 part of BASF antioxidant. The spherical powder and the irregular powder are reasonably proportioned, so that the powder stacking density and sintering compactness are improved, and meanwhile, the flowability is considered.

The present invention relates to the technical field of metal coatings, and specifically relates to a high-temperature resistant metal coating and its preparation process. In the present invention, first, acrylic acid and 1,1,3,3-tetramethyldisiloxane are used as raw materials to prepare intermediate A, and diethanolamine, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and paraformaldehyde are reacted to obtain intermediate B; intermediate A and intermediate B are reacted at a molar ratio of 1:2 to obtain a silicon-containing flame-retardant diol; then polytetrahydrofuran ether diol 2000 and the silicon-containing flame-retardant diol are mixed and reacted with isophorone diisocyanate and chain-extended to obtain a modified polyurethane emulsion; the modified polyurethane emulsion, deionized water, wetting agent, defoaming agent, dispersant, titanium dioxide, barium sulfate powder, zinc phosphate, leveling agent, and thickening agent are mixed and stirred to obtain a high-temperature resistant metal coating.

This invention discloses a method for synergistic surface modification of tungsten-copper powder to inhibit the decomposition of polyoxymethylene (POM), belonging to the field of polymer material anti-degradation modification technology. This invention addresses the problem that tungsten-copper powder easily catalyzes the severe degradation of POM during PIM tungsten-copper feedstock mixing and injection molding, leading to poor feedstock flowability, injection instability, large fluctuations in product size and weight, and low yield. First, the tungsten-copper powder is activated by low-temperature plasma etching to construct a reaction interface. Then, a silica barrier film is prepared using tetraethyl orthosilicate as the silicon source and modified with fluorosilicone, loaded with a metal soap neutralizer, grafted with a hindered phenolic antioxidant, and simultaneously introduced with epoxy active groups to construct a multi-component synergistic degradation inhibition system. This invention, through multi-step synergistic modification, precisely controls the modification process, comprehensively inhibiting POM decomposition. When the modified powder is blended with POM, a capping reaction occurs, blocking the unzipping degradation pathway of POM, improving the compatibility of the filler and the matrix, and ensuring the continuous and stable preparation and injection molding of PIM tungsten-copper feedstock.

The invention relates to the technical field of formaldehyde copolymer production, and discloses a trioxymethylene static crystallization separation method which comprises the following steps: S1, cooling crystallization: the crystallization temperature is 25-30 DEG C, and the crystallization time is 3-4 hours; s2, discharging mother liquor; s3, sweating, wherein the sweating temperature is 50-55 DEG C, and the sweating time is 2-2.5 h; and S4, melting to obtain a high-purity product. According to the invention, the characteristic that the solubility of trioxymethylene is reduced along with temperature reduction is utilized, and separation and purification are realized through temperature gradient regulation and control. The content of trioxymethylene in the prepared finished product reaches 94-96% and is higher than that in the prior art by 90-92%, the formaldehyde content is only 0.1-0.2%, and the impurity content is lower.

To provide a polyacetal resin composition which can further improve physical properties such as mechanical strength and hot water resistance, while using a modified cross-section glass fiber, when being colored by black, particularly, carbon black.SOLUTION: A polyacetal resin composition contains, with respect to 100 pts.mass of (A) a polyacetal resin, 1 to 100 pts.mass of (B) a modified cross-section glass fiber which is surface-treated with (B1) at least one selected from at least one isocyanate compound selected from the group consisting of a blocked isocyanate compound and a polyurethane resin, an amino silane coupling agent, an epoxy resin, and an acid copolymer, and (B2) a boric acid compound, and 0.001 to 3 pts.mass of (C) at least one binder selected from the group consisting of an organometallic compound containing a metal selected from Sn, Zn and PB, a boric acid compound and a quaternary onium salt compound.SELECTED DRAWING: None