39 results about "Urea-formaldehyde" patented technology

The invention relates to the technical field of fertilizer production and industrial solid waste resource utilization, and particularly discloses a method for producing a urea formaldehyde polyglutamic acid compound fertilizer from phosphorus and potassium mixed acid raffinate. According to the method, phosphorus-potassium mixed acid slurry, polyglutamic acid and urea formaldehyde are used as main raw materials, and the preparation method comprises the steps of raw material reaction and mixed acid preparation, multi-stage neutralization and functional agent mixing, slow-release nitrogen source mixing, returned material pretreatment and granulation, screening and wrapping, process waste heat recovery and the like. The product disclosed by the invention can be applied as a special compound fertilizer with nutrient slow release and biological stimulation functions, and has the advantages of balanced nutrients, high utilization rate and capability of improving soil. Besides, according to the preparation method, high-valued resource utilization of the phosphorus-potassium mixed acid raffinate is achieved, and through ammoniation pretreatment of returned materials and systematic recovery of reaction waste heat, the preparation method has the advantages that the raw material cost is reduced, the product performance is improved, and the production energy consumption is reduced.

The application relates to a composite film material, a urea-formaldehyde product and a preparation method thereof, and a toilet bowl. The composite film material comprises a modified film material, the modified film material comprises a reinforcing cloth and a PVB matrix coated on the surface of the reinforcing cloth and filled in the reinforcing cloth, the total thickness of the modified film material is 0.1mm-2mm, the modified film material is provided with a plurality of through holes arranged in the thickness direction, and the diameter of each through hole is 1mm-5mm; the grammage of the reinforcing cloth is 10g / m 2 ~120g / m 2 ; the material for preparing the PVB matrix comprises PVB 85-92 parts and a plasticizer 8-15 parts in mass fraction, the total mass fraction of the PVB and the plasticizer is 100 parts, and the viscosity of a 10% PVB ethanol solution at 20 DEG C is 30s-120s. The composite film material has high hardness and high impact resistance, is applied in the urea-formaldehyde product, and is favorable for improving the impact resistance of the urea-formaldehyde product.

The invention belongs to the technical field of melamine modified urea-formaldehyde rubber powder, and particularly relates to ENF-grade melamine modified urea-formaldehyde rubber powder as well as a preparation method and application thereof. The ENF-grade melamine modified urea-formaldehyde rubber powder is prepared from the following components in parts by weight: 50 to 60 parts of urea, 90 to 110 parts of a formaldehyde solution, 10 to 15 parts of melamine, 0.2 to 0.5 part of hyperbranched polyglycerol and 10 to 20 parts of a cellulose porous material. The specific hyperbranched polyglycerol and cellulose porous material are adopted, under the specific preparation method, the melamine modified urea-formaldehyde glue powder with the low free formaldehyde content can be obtained, the formaldehyde emission of the prepared plywood is smaller than 0.025 mg / m, the ENF-level requirement is met, and meanwhile the plywood has the excellent bonding strength and water resistance.

The invention discloses a flame-retardant polyester modified urea-formaldehyde adhesive as well as a preparation method and application thereof, and belongs to the technical field of wood processing and artificial board adhesives. The preparation method comprises the following steps: mixing glycerol and maleic anhydride, and carrying out first heating reaction to obtain a polyester prepolymer; mixing the polyester prepolymer and glycerin, and carrying out a second heating reaction to obtain functionalized hyperbranched polyester; dissolving the functionalized hyperbranched polyester in acetonitrile, then adding phenylphosphoryl dichloride for reaction, heating and stirring for reaction, and removing the solvent and byproducts after the reaction is finished to obtain hyperbranched flame-retardant polyester; and uniformly mixing the hyperbranched flame-retardant polyester aqueous solution, urea-formaldehyde resin and water to obtain the modified urea-formaldehyde adhesive. Through an innovative strategy of'structural design-chemical bonding ', the long-standing core contradiction that'flame retardance-performance' is difficult to consider in urea resin flame-retardant modification is successfully solved, an efficient and durable flame-retardant modification solution with excellent comprehensive performance is provided, and the industrial application value is significant.

This invention discloses a supported anti-sulfurization reducing agent and its preparation method, relating to the technical field of rubber additives. A supported anti-sulfurization reducing agent includes an adhesive layer and an inner capsule. The adhesive layer is formed by blending a carrier rubber and a fatty acid salt. The inner capsule includes a core material and an inner capsule wall. The core material is the anti-sulfurization reducing agent, while the inner capsule wall is formed by reacting and curing an amino-modified liquid isoprene rubber and a urea-formaldehyde prepolymer. This application, by using microencapsulation, prepares an anti-sulfurization reducing agent with a double-layered supported structure. This not only effectively improves the problems of poor compatibility and difficult dispersion of pure anti-sulfurization reducing agents in rubber compounds, but also effectively protects the active ingredients, which is beneficial for improving the actual utilization rate of the anti-sulfurization reducing agent, reducing the amount of anti-sulfurization reducing agent added, and thus reducing the production cost of rubber products.

This invention relates to the field of adhesive technology and discloses an anti-aging phenolic resin-based urea-formaldehyde adhesive and its preparation method. The adhesive is composed of 95-100 parts phenol, 120-160 parts 37% formaldehyde solution, 80-110 parts urea, 3-4.5 parts modifier, 1.5-1.8 parts curing agent, and 1.8-2.2 parts anti-aging agent. The preparation method includes four steps: preparation of phenolic resin prepolymer, preparation of urea-formaldehyde resin prepolymer, composite modification, and post-treatment. This invention, through the synergistic effect of composite modification and anti-aging agent, solves the defects of traditional urea-formaldehyde adhesives, such as high formaldehyde release, poor anti-aging performance, and insufficient water resistance, while possessing excellent environmental friendliness, adhesion, and durability, making it suitable for fields such as the production of engineered wood products.

The utility model relates to the technical field of urea formaldehyde compound fertilizer production, and discloses a urea formaldehyde preparation system, which comprises a reaction tank and an intermediate tank, the reaction tank is communicated with a water inlet pipe, an air inlet pipe, a feed inlet and a liquid outlet pipe; a first conveying pump is arranged on the liquid outlet pipe; the other end of the liquid outlet pipe is communicated with a middle tank, the middle tank is communicated with a discharging pipe, a second conveying pump is arranged on the discharging pipe, a plurality of spray heads are arranged at the other end of the discharging pipe, and the spray heads extend into a secondary dryer or a granulator. According to the scheme, urea and formaldehyde react to form the urea formaldehyde solution, and then the urea formaldehyde solution is sprayed on the surface of the compound fertilizer to form the urea formaldehyde slow-release compound fertilizer, so that the coating uniformity of urea formaldehyde on the surface of the compound fertilizer is effectively improved, and the slow-release uniformity of the urea formaldehyde compound fertilizer is improved.

The invention discloses a modified montmorillonite-based lubricant and a preparation method thereof, and belongs to the technical field of lubricants, oleic acid and diethylenetriamine are cyclized and quaternized to prepare an oleic acid-based imidazoline quaternary ammonium salt corrosion inhibitor, the oleic acid-based imidazoline quaternary ammonium salt corrosion inhibitor is used for organic modification of nano montmorillonite, a silane coupling agent is further adopted for silanization treatment, and the modified montmorillonite-based lubricant is prepared. The preparation method comprises the following steps: preparing silane modified corrosion-inhibition montmorillonite, carrying out in-situ polymerization coating by taking a urea-formaldehyde prepolymer as a wall material to form montmorillonite modified corrosion-inhibition microcapsules, and carrying out copolymerization on acrylic acid, N, N-bis (2-hydroxyethyl) aminomethylene diethyl phosphonate and trifluoromethacrylate to obtain the modified polyacrylate dispersant with heat-resistant and dispersion-stable functions. The microcapsule, a dispersing agent, dibasic acid ester oil, PAO base oil and an antioxidant are compounded in proportion to form the modified montmorillonite-based lubricant.

The process comprises the following steps: S1, adding urea and a formaldehyde solution into a reaction kettle according to a molar ratio of 1: (1.8-2.2), then adding sodium hydroxide to adjust the pH value to 7.0, and carrying out a stirring reaction to generate a hydroxymethyl urea solution; adding sulfuric acid into the hydroxymethyl urea solution, adjusting the pH value to 4.5, and continuously stirring for reaction to obtain a urea formaldehyde solution; s2, weighing casein, glutamic acid, asparaginic acid and water in proportion, and uniformly mixing to obtain a synergistic solution; s3, weighing urea, monoammonium phosphate, potassium chloride, modified charcoal, polyethylene glycol and sodium carboxymethyl cellulose, and uniformly mixing to obtain a solid mixture; s4, putting the solid mixture into a rotary drum granulator, respectively spraying a urea formaldehyde solution and a synergist into a solid mixture bed through a granulation spray head, synchronously spraying liquid ammonia and sulfuric acid through a special spray head, and enabling the liquid ammonia and the sulfuric acid to generate a neutralization reaction on the surface of the solid mixture to obtain a compound fertilizer precursor; and S5, drying the compound fertilizer precursor to obtain the compound fertilizer.

The application discloses a kind of composite toughening material, article and its preparation method, the composite toughening material is made of shell material and core material wrapped in the shell material;Wherein, the composite toughening material has excellent toughening effect, has good adhesion and compatibility to existing material, for example, urea-formaldehyde, realizes cover plate product crack resistance without changing the ceramic texture and high hardness of urea-formaldehyde material quality, and the composite toughening material production process is simple, easy to mass production and marketization.

This invention relates to the field of resin preparation technology, and particularly to a method for preparing a water-soluble etherified phenol-urea-formaldehyde mixed resin, comprising the following steps: S1, adding an alkaline catalyst, formaldehyde, urea, and molten phenol to a reaction vessel for reaction, stirring and heating to 40-50°C for 4-5 hours; S2, adding an organic acid to the reaction system in step S1 under stirring to adjust the pH value to 4.9-5.4; S3, adding urea and thiourea to the reaction vessel and reacting at a reaction temperature of 45°C for 60 minutes; S4, adding an alcohol compound to the reaction vessel, raising the reaction temperature to 50°C and reacting for 60 minutes; S5, adding an alkaline solution to the reaction system obtained in step S4 to adjust its pH value to 6.5-6.8, and then stirring at 50°C to obtain the water-soluble etherified phenol-urea-formaldehyde mixed resin. The water-soluble etherified phenol-urea-formaldehyde mixed resin material prepared by this method has good water solubility and low viscosity, which can improve the profile control and water shut-off effect in oil fields.

The utility model discloses a kind of urea formaldehyde resin storage tanks with low aldehyde emission structure, it is related to urea formaldehyde resin storage technical field, including tank body and discharge mechanism, the top of tank body is fixedly connected with discharge mechanism, and discharge mechanism includes the ventilation pipeline fixedly connected in the position of tank body outer surface, the outer surface of ventilation pipeline is provided with ventilation valve, and the top of ventilation pipeline is fixedly connected with adsorption tower, the inside of adsorption tower is provided with activated carbon adsorption layer, and the top of activated carbon adsorption layer is fixedly connected with molecular sieve composite adsorption layer, ventilation pipeline is stainless steel material, strong corrosion resistance, its outer surface is connected ventilation valve through flange.The urea formaldehyde resin storage tank with low aldehyde emission structure compared with existing ordinary urea formaldehyde resin storage tank, prolongs pipeline life, stabilizes tank pressure, improves waste gas purification and environmental protection, reduces cost, and enhances coating adhesion, reduces corrosion rate, guarantees resin purity, reduces cleaning and leakage risk.

The present invention relates to lignocellulosic nanofibres (LNFC) or biopolymeric reinforcing nanoadditive as a mechanical reinforcement of low-molar-ratio phenol formaldehyde (PF) and urea formaldehyde (UF) thermosetting adhesives, wherein the use of natural nanocompounds based on lignin and cellulose makes the nanoadditive or nanofibre a "green" or environmentally friendly additive, said additive being useful in the production of wood-based composites. The LNFCs are made by means of a process that does not involve chemical additives and which is based on thermomechanical wood pulp, using microshredding and high-pressure microfluidsation. The present natural nanoadditive or natural reinforcement fibre is intended for the industry of manufacturing plywood, medium density fibreboard (MDF) and particleboard.

The present application relates to carbon capture and storage technology field, especially to a kind of modified resin carbon dioxide capture agent and its preparation method and regeneration method, comprising the following weight parts of raw materials: urea formaldehyde resin 2-10 parts, cysteine 0.5-2 parts, chitosan 1-5 parts, gelatin 5-15 parts, titanium dioxide 0.5-2 parts and N-hydroxyethyl piperazine 4-8 parts.The modified resin carbon dioxide capture agent obtained by careful design of raw material combination and interaction, its internal abundant active site and pore structure significantly improve its carbon dioxide adsorption capacity;At the same time, it not only has good anti-UV aging ability, but also can catalyze the decomposition of NO X Reduce its damage to resin, so that the resin can maintain good performance stability during long-term use;Finally, the interaction of various components in the resin makes the modified resin form a strong anti-interference structure, and this structure can make the modified resin still maintain good capture performance in complex environment.

The invention discloses a compound fertilizer for preventing and treating asparagus stem blight and a preparation method thereof, and belongs to the technical field of agriculture. The compound fertilizer for preventing and treating asparagus stem blight is prepared from the following raw materials in parts by mass: 220 to 240 parts of chicken manure, 80 to 90 parts of rice straw, 5 to 7 parts of urea, 2.5 to 4 parts of urea formaldehyde, 10 to 12 parts of plant ash, 0.5 to 2 parts of potassium chloride, 8 to 10 parts of calcium superphosphate, 0.1 to 0.4 part of sodium molybdate, 0.1 to 0.5 part of diethyl aminoethyl hexanoate and 5 to 8 parts of biomass charcoal. According to the designed preparation scheme of the compound fertilizer for preventing and treating the asparagus stem blight, the yield and quality of asparagus can be improved, the asparagus stem blight can be effectively prevented and treated, and drug resistance is not prone to being generated. Moreover, the fertilizer scheme is lower in production cost, green, pollution-free and longer in fertilizer efficiency, can reduce the topdressing frequency when being used for topdressing of asparagus, and has a very good application prospect.

The invention provides specific uric acid conjugate immobilized resin as well as a preparation method and application thereof, and belongs to the technical field of resin. The preparation method comprises the following steps: preparing urea formaldehyde amino organic resin microspheres, reacting with a silane coupling agent with an epoxy group, hydrolyzing, calcining, modifying with concentrated nitric acid, reacting with acrylonitrile, loading a molecularly imprinted material on the surface, eluting, and drying to obtain the specific uric acid conjugate immobilized resin. According to the prepared specific uric acid conjugate immobilized resin, controllable preparation of a high-capacity, high-selectivity and recyclable uric acid specific adsorption material is achieved, a brand new platform is provided for precise diagnosis of hyperuricemia and blood purification, and the specific uric acid conjugate immobilized resin has wide application prospects.

The invention belongs to the field of agricultural machinery surface engineering, aims to solve the problem of poor adaptability of an agricultural machinery soil touch component coating under complex working conditions, and provides an anti-sticking wear-resistant composite coating and a preparation method thereof. The coating comprises a base material and a composite functional coating, after the base material is pretreated, Ra is 3-5 [mu] m, and the surface of the base material is provided with a procambarus clarkii imitated crescent texture (R = r = 50 [mu] m, spacing a = 250 [mu] m, b = 200 [mu] m, and depth h = 50 [mu] m); the composite functional coating is based on a corrosion-resistant adhesion system (PDMS, KH-560 and a nano mass ratio of 5: 1: 0.5), and contains an anti-sticking wear-resistant core phase (a mass ratio of PTFE micro powder to modification is 3-4: 1), a toughness reinforcing phase (modified PI nano fiber) and a self-healing unit (urea formaldehyde coated PTFE microcapsules). The preparation method comprises the steps of substrate pretreatment, texture laser etching, viscosity coating suspension preparation, step-by-step curing after air spraying and gradient cooling. The prepared coating has an acid-alkali soaking peeling rate of less than or equal to 8%, a low-temperature cracking rate of less than or equal to 4% and an operation life of more than or equal to 520 h, and has excellent anti-sticking, wear-resistant, corrosion-resistant and self-healing performances.

The invention aims to protect an amino resin controlled-release fertilizer coating material and application thereof. Melamine, malondialdehyde, butanedialdehyde, glutaraldehyde, adipaldehyde and the like are taken as raw materials and are cross-linked under the condition of a basic catalyst to obtain a melamine resin monomer, and then the melamine resin monomer is further polymerized and cross-linked under the catalysis of an organic acid catalyst compound to form the amino resin controlled-release fertilizer coating material with a three-dimensional net-shaped hydrophobic structure. The amino resin controlled-release fertilizer coating material designed and synthesized by the invention is good in degradation performance after being applied to soil, and environmental pollution is avoided; and the film material degradation product is an efficient urea formaldehyde slow-release fertilizer, and can be absorbed by plants as a nutrient. Meanwhile, raw materials used by the synthetic amino resin controlled-release fertilizer coating material are low in cost, and the prepared controlled-release fertilizer coating is excellent in controlled-release performance, stable in structural performance and high in cost performance, has good economic benefits and is suitable for large-scale popularization.

The utility model discloses a titanium porcelain silicate decorative plate belongs to the technical field of decorative plate, titanium porcelain silicate decorative plate, titanium porcelain silicate decorative plate includes silicate fibre framework, first outer wrapping layer, second outer wrapping layer, and the inner middle part of silicate fibre framework is fixed with small silk screen, and is fixed with urea -formaldehyde foam block through small silk screen, and the outside of urea -formaldehyde foam block is fixed with large silk screen, first outer wrapping layer, second outer wrapping layer all are located the outside of large silk screen, and first outer wrapping layer, second outer wrapping layer are glued through high temperature resistance glue, and form the sealed package of silicate fibre framework outside, and the outside of first outer wrapping layer, second outer wrapping layer is sprayed titanium porcelain paint, and forms the dense titanium porcelain paint layer. It has total mass light, high temperature resistance, fire -resistant not flammable, resistant to enjoy etc. characteristics, can realize the effective recycling of silicate decorative plate, has improved the practical value of titanium porcelain silicate decorative plate.

The invention relates to the technical field of adhesive preparation, in particular to modified gelatin and copper-doped manganese dioxide low-formaldehyde urea-formaldehyde glue and a preparation method thereof. According to the technical scheme, the modified gelatin and copper-doped manganese dioxide low-formaldehyde urea-formaldehyde glue is prepared from the following raw materials in parts by weight: 100 parts of urea-formaldehyde resin prepolymer; 8 to 25 parts of modified gelatin; 0.5 to 1.5 parts of nano copper doped manganese dioxide; the modified gelatin is gelatin subjected to protease enzymolysis treatment, and the average molecular weight of the modified gelatin is 3,000-60,000 Da; the nano-copper doped manganese dioxide is a mesoporous material with the copper doping amount of 3-10 mol%; after the adhesive is hot-pressed and cured, the formaldehyde release amount of a prepared artificial board is smaller than or equal to 0.025 mg / m, the dry-state bonding strength is larger than or equal to 0.80 MPa, through the three-stage synergistic effect of weak acid initial process source control, modified gelatin in-situ capture and nano-catalyst oxidative conversion, formaldehyde is inhibited and eliminated from the source to the process in an all-around mode, and the prepared artificial board is stable in formaldehyde release amount and high in bonding strength. And the technical bottleneck that the conventional urea-formaldehyde glue is difficult to stably reach the ENF level is solved.

The utility model discloses a single-stage absorption tower for removing formaldehyde in industrial waste gas by using a urea solution. The single-stage absorption tower comprises a tower body, a gas mixing and distributing system and an absorption liquid spraying system, according to the utility model, compressed air is introduced and heated by utilizing the gas mixing and distributing system, then industrial waste gas is mixed with the compressed air, and the mixed gas is sprayed into mist through the gas distributor, so that the industrial waste gas is uniformly distributed in the packing layer; the absorption liquid spraying system atomizes a urea solution in an absorption liquid storage pool at the bottom of the tower body into tiny liquid drops, the tiny liquid drops are evenly sprayed to the filler layer, and the urea solution reacts with formaldehyde in the industrial waste gas to generate urea resin. The formaldehyde absorption efficiency and the reaction efficiency of formaldehyde and urea are greatly improved through the measures of introducing heated compressed air, atomizing and distributing the gas distributor, increasing the gas-liquid contact area by the filler and the like, and the resource utilization of formaldehyde in industrial waste gas can be realized while secondary pollution is avoided.

The invention discloses antibacterial hydrogel for a controlled-release fertilizer and a preparation method of the antibacterial hydrogel, and belongs to the technical field of controlled-release fertilizers. The preparation method comprises the following steps: by taking soluble corn starch, cellulose nanocrystals, chitosan and chitin nanofibrils as main matrix materials, constructing a core-shell silver-zinc oxide nano antibacterial agent in situ, and compounding the core-shell silver-zinc oxide nano antibacterial agent with functionalized graphene oxide and an acrylamide monomer; the preparation method comprises the following steps: entrapping a nitrogen-phosphorus-potassium fertilizer and a urea-formaldehyde prepolymer in a starch-based mother solution, blending with a chitosan solution, and carrying out in-situ covalent-ionic composite cross-linking polymerization through an ammonium persulfate / tetramethylethylenediamine initiation system to form three-dimensional network hydrogel; and carrying out extrusion / spray granulation and freeze-drying-hot air combined drying to obtain dry-based granules. The hydrogel has high mechanical strength, excellent slow release performance, long-acting broad-spectrum antibacterial property and environmental responsiveness, the fertilizer utilization rate is remarkably increased, soil pathogenic bacteria are inhibited, and the hydrogel is suitable for modern sustainable agriculture.

The invention discloses a high-density fiber wallboard and a preparation method thereof, and belongs to the technical field of wallboards, the high-density fiber wallboard comprises the following components by weight: 100-200 parts of wood fiber, 50-100 parts of an inorganic filler, 30-100 parts of a triazine derivative and melamine modified urea-formaldehyde glue, 2-5 parts of a waterproof agent, and 0.4-1 part of a curing agent; the high-density fiber wallboard is prepared by adding the inorganic filler, the triazine derivative and the melamine modified urea-formaldehyde glue into the wood fiber, and the prepared high-density fiber wallboard has the effects of high strength, high modulus, high density and low formaldehyde release, and has the advantages of high strength, high modulus, high density and low formaldehyde release. The inner organizational structure is fine and dense, particularly has dense edges, can be processed into various special-shaped edges, can be directly coated without edge sealing, can achieve a better modeling effect, and has a wide application prospect.

The invention discloses a liquid slow-release nitrogen fertilizer and a preparation method and device thereof, and belongs to the field of fertilizers. The liquid slow-release nitrogen fertilizer is characterized by being generated by common reaction of urea, formaldehyde and a polymer additive, wherein the polymer additive is generated by reaction of modified sodium carboxymethyl cellulose and an acrylate-acrylamide copolymer; the preparation method of the liquid slow-release nitrogen fertilizer comprises the following steps: firstly generating a urea formaldehyde polymer and a polymer additive, then mixing the two to obtain a composite system, finally adjusting the pH value, and performing low-temperature evaporation to obtain a final product. The device for preparing the liquid slow-release nitrogen fertilizer comprises a reaction kettle with a low-temperature evaporation function; the liquid slow-release nitrogen fertilizer can solve the problem that a fertilizer pipeline and a storage container are blocked due to the phenomena of crystallization, freezing and the like of the fertilizer in a low-temperature environment, meanwhile, the slow-release performance of the fertilizer is considered, the liquid slow-release nitrogen fertilizer is suitable for storage, transportation and use in cold regions, and the application range and the application scene of the fertilizer are expanded; and the structure of the device can be simplified, the occupied area is reduced, and the cost is saved.

The invention provides a self-repairing microcapsule with a double-shell nested structure as well as a preparation method and application of the self-repairing microcapsule, and relates to the technical field of coatings. The preparation method comprises the following steps: (1) mixing an isocyanate monomer or prepolymer with a repairing agent to serve as an oil phase; the preparation method comprises the following steps: dissolving an emulsifier in water as a water phase, carrying out homogenization treatment to obtain an oil-in-water emulsion, adding polyol and a catalyst, and carrying out a reaction at a certain temperature to obtain a single-shell microcapsule encapsulating a repairing agent; and (2) dispersing the single-shell microcapsule in deionized water, adding a urea formaldehyde prepolymer and resorcinol, adjusting the pH value, and reacting at a certain temperature to obtain the self-repairing microcapsule with the double-shell nested structure. The environment stability, the anti-shearing capability and the reliable repairing performance are excellent.

The present invention provides a method for preparing a urea-formaldehyde precursor used in the preparation of a urea-formaldehyde resin, and a urea-formaldehyde precursor prepared by the method.

Provided is a mold-forming binding agent composition that can suppress cracking of a mold and can increase the final mold strength by increasing the initial strength of the mold through an increase in the curing rate of the mold and by increasing the flexibility of the mold during mold removal without depending on the nitrogen content. This mold-forming binding agent composition comprises: a furan resin containing a furfuryl alcohol-urea-aldehyde condensate and a furfuryl alcohol-aldehyde condensate; a furfuryl alcohol; and a methyl methacrylate-based resin.

This invention discloses a halogen-free flame retardant suitable for urea-formaldehyde resin, flame-retardant urea-formaldehyde resin using the same, and flame-retardant plywood. The halogen-free flame retardant of this invention comprises the following components: lightly calcined magnesium oxide, magnesium sulfate heptahydrate, retarder, water, boron-based flame retardant, water-reducing agent, blending agent, and magnesium calcium carbonate. The flame-retardant urea-formaldehyde resin is obtained by uniformly mixing the above-mentioned halogen-free flame retardant, urea-formaldehyde resin, and ordinary flour. Then, the flame-retardant urea-formaldehyde resin and veneer are cold-pressed and hot-pressed to obtain flame-retardant plywood. The halogen-free flame retardant of this invention, through a magnesium gel system, improves the bonding strength and flame-retardant properties of urea-formaldehyde resin. Combined with the boron-based flame retardant, it exhibits good stability in urea-formaldehyde resin, exerting a synergistic flame-retardant effect. This invention adds magnesium cement to urea-formaldehyde resin, which, along with other flame-retardant components, can be fully dispersed in the urea-formaldehyde resin. Plywood treated with this invention can achieve a B1 flame-retardant rating, and the addition of the halogen-free flame retardant significantly reduces the corrosivity of the flame-retardant plywood.

The invention relates to a dual-network chitosan-urea formaldehyde water-retaining slow-release fertilizer and a preparation method and application thereof.The preparation method comprises the steps that 1, a certain amount of chitosan, acrylic acid with the molar neutralization degree of 85% and acrylamide are mixed in deionized water according to a certain mass ratio, and the mixture is stirred and mixed to be uniform under the constant-temperature water bath condition; (2) adding a certain amount of urea into the mixed system, and fully and uniformly mixing; (3) adding a certain amount of potassium persulfate solution with a certain concentration, and carrying out an initiation reaction; (4) adding an N, N '-methylene bisacrylamide solution, and carrying out a cross-linking reaction; and (5) taking out the product, cutting the sample into blocks, and drying to obtain the dual-network chitosan-urea formaldehyde water-retaining slow-release fertilizer. The prepared dual-network chitosan-urea formaldehyde water-retaining slow-release fertilizer is used for agricultural water and fertilizer integrated management, and can improve the water holding rate of soil, delay nutrient release and promote crop growth.