258 results about "Suspension polymerization" patented technology

The invention discloses a high-strength low-density proppant as well as a preparation method and an in-situ generation method thereof. The proppant is prepared by compounding recycled glass fiber reinforced plastic powder or glass fiber powder with different meshes and recycled glass fiber reinforced plastic powder in different proportions and blending a styrene system / unsaturated polyester resin system in different proportions. The glass fiber reinforced plastic powder as the filler can improve the mechanical properties of the proppant, such as strength and toughness. The matrix is made of polystyrene or unsaturated polyester or other high polymer materials and is low in density. Therefore, the proppant has the characteristics of high strength and low density. The invention discloses a preparation method of a high-strength and low-density proppant, which can produce the high-strength and low-density proppant with uniform particle size distribution on a large scale by adopting a suspension polymerization method, and can efficiently recover a large amount of glass fiber reinforced plastic wastes. The suspension polymerization method is simple to operate, the produced proppant is high in roundness and sphericity, the mining cost of a coal-bed gas well can be reduced, and the yield of coal-bed gas can be increased.

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 provides an adsorbent capable of simultaneously adsorbing bilirubin and cytokines and a preparation method and application thereof, and the preparation method comprises the following steps: carrying out suspension polymerization reaction on a styrene monomer and a polyvinyl cross-linking agent in a dispersion medium under the action of a continuous multi-component pore-foaming agent and an initiator to prepare polystyrene-based macroporous resin; carrying out chloromethylation reaction on the polystyrene-based macroporous resin to prepare chlorine balls; carrying out post-crosslinking reaction on the chloromethylated beads to prepare the adsorbent capable of adsorbing bilirubin and cytokines at the same time; the continuous multi-component pore-foaming agent comprises a first pore-foaming agent, a second pore-foaming agent and a third pore-foaming agent of which the solubility parameters are gradually increased in sequence; the temperature of the suspension polymerization reaction is adjusted according to the mass fraction of the polyvinyl cross-linking agent in the monomer mixture and the solubility parameter of the continuous multi-component pore-foaming agent, and the monomer mixture is composed of styrene monomers and the polyvinyl cross-linking agent. The bilirubin and cell factors can be adsorbed at the same time, and the safety of blood purification is improved.

The invention relates to polystyrene cation exchange resin as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving a dispersing agent in a solvent to obtain a dispersed phase for suspension polymerization reaction, uniformly mixing a reaction monomer, a cross-linking agent, a pore-foaming agent and an initiator, and carrying out suspension polymerization reaction under segmented stirring and segmented temperature change to prepare copolymer microspheres; and putting the dried microspheres into a reaction kettle, swelling, carrying out sulfonation reaction through a variable temperature program on the basis to obtain sulfonated microspheres, and carrying out alkali exchange reaction on the sulfonated microspheres to obtain the final product cation exchange resin. Compared with the prior art, the cation exchange resin preparation method provided by the invention has the characteristics of simple and feasible process, easiness in large-scale production, low cost, high specific surface area, high adsorption capacity and high separation efficiency, and is especially suitable for separating and purifying substances containing amino groups or aminoglycosidic bonds.

The invention discloses a macroporous resin material and a preparation method thereof, and macroporous resin with high specific surface area and excellent adsorption performance is obtained through a specific modified acrylate polymeric monomer and a preparation method of the macroporous resin material. The method comprises the following steps: reacting quercetin, methyl vanillate and acryloyl chloride to prepare a modified acrylate polymeric monomer, mixing the modified acrylate polymeric monomer with polyvinyl alcohol, ethylene glycol dimethacrylate, dodecanol, benzoyl peroxide and the like, and carrying out suspension polymerization to prepare the macroporous resin material. The prepared macroporous resin material has excellent performance in the aspects of pore structure, polarity and the like, can be widely applied to the related fields of adsorption separation and the like, and provides a new thought and method for research and development of the macroporous resin material.

The invention discloses a preparation method of ulinastatin adsorption resin, and belongs to the technical field of adsorption resin. Comprising the following steps: (1) preparing a water phase: adding pure water, gelatin, cellulose, sodium chloride and lignin into a reaction kettle until the materials are fully dissolved; (2) preparing an oil phase, wherein the oil phase contains divinylbenzene, methyl acrylate, benzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, triallyl isocyanurate, tripropanol alkyl trimethacrylate and methylbenzene, and the oil phase is uniformly stirred and mixed with the methylbenzene and the trivinylbenzene, the methyl acrylate, the benzoyl peroxide, the tert-butyl peroxy-2-ethylhexanoate, the triallyl isocyanurate, the tripropanol alkyl trimethacrylate and the methylbenzene; (3) suspension polymerization: putting the oil phase into the water phase, and carrying out staged heating reaction; (4) amination reaction; (5) alkylation reaction; and (6) acid-base alcohol treatment. Compared with the existing resin, the resin disclosed by the invention has the characteristics of high adsorption exchange rate, high desorption rate and high desorption concentration on ulinastatin, and the yield of ulinastatin is increased by 1.17 times compared with that of D215 resin.

The invention belongs to the technical field of foam materials, and particularly relates to a wave-absorbing functional foamable PMI precursor bead, a preparation method thereof and a wave-absorbing functional PMI foam material. According to the technical scheme, the method comprises the following steps: 1) adding deionized water, inorganic salt and a dispersing agent into a reaction container, mechanically stirring uniformly, and heating to a polymerization temperature to obtain a suspension polymerization water phase; 2) uniformly mixing a monomer, an initiator, a foaming agent and a cross-linking agent at room temperature, adding the mixture into the suspension polymerization water phase, and performing suspension polymerization under a stirring condition to obtain foamable PMI precursor beads; and 3) washing the PMI precursor beads with water for multiple times, and drying to obtain the wave-absorbing functional foamable PMI precursor beads. And placing the wave-absorbing functional foamable PMI precursor beads in a mold, and carrying out high-temperature heat treatment foaming to obtain the wave-absorbing functional PMI foam material. The intrinsic performance of the base material is not damaged, the magnetic particles are uniformly dispersed in the base material, and the wave absorbing effect is good.

The invention provides highlight black ASA (acrylonitrile-styrene-acrylate) resin as well as a preparation method and application thereof. According to the method, the ASA resin is prepared by adopting a polymerization method, and the method comprises the following steps: adding an ASA graft copolymer serving as a rubber phase into a suspension polymerization system which serves as a plastic phase and contains styrene and acrylonitrile in an emulsion state, and adding a phase regulator into the suspension polymerization system to prepare the ASA resin. The ASA resin has the advantages that the ASA graft copolymer is used as a dispersion phase, charge balance on the surfaces of ASA emulsion particles in a suspension polymerization system can be broken, transition from an emulsion state to a suspension state in the suspension polymerization system is realized, and finally polymerization of styrene and acrylonitrile in the suspension state is realized; the ASA resin has the characteristic of an'island 'two-phase structure taking the styrene-acrylonitrile copolymer as a continuous phase, and the micromixing of two phases of rubber and plastic in the ASA resin is more uniform. The ASA resin disclosed by the invention has high gloss and high impact strength, and a high light black effect can be obtained after the ASA resin is dyed by a black dye.

The application discloses large-diameter core-shell polymer particles, a preparation method and application thereof. The large-diameter core-shell polymer particles have a particle size of 1-50 microns; the structure of the particles comprises a water-insoluble soft substance layer and a hard substance layer, and the weight ratio of the soft substance layer to the hard substance layer is 1:0.1-10, and the hard substance layer is located at the outer layer of the soft substance layer. The particles are prepared by using a modified aqueous suspension polymerization and / or emulsion polymerization method. The obtained particles can improve the hardness of an electric core, inhibit the deformation of the electric core, and do not affect the air permeability. Compared with general micron-level homogeneous polymer particles, the particles provided by the application have a soft core and hard shell structure, which is also beneficial to improving the performance of a diaphragm. The hard substance layer located at the outer layer of the particles ensures that the diaphragm coating is not sticky after drying, so that the diaphragms are not adhered to each other after being wound. The soft substance layer located at the inner layer of the particles can provide strong adhesion, so that the diaphragm and the pole piece have higher peeling strength.

The invention belongs to the field of binders, and particularly relates to a reversed-phase suspension polymerization aqueous binder for a lithium battery and a preparation method of the reversed-phase suspension polymerization aqueous binder. The reversed-phase suspension polymerization aqueous binder for the lithium battery provided by the invention is prepared from the following raw materials: polysaccharide, an acrylic monomer, a dispersing agent, an initiator, a cross-linking agent, neutralizing alkali, an oil-phase solvent and deionized water, and the product is prepared by adopting reversed-phase suspension polymerization. The reversed-phase suspension polymerization aqueous binder for the lithium battery has excellent binding performance, the 180-degree peel strength is larger than 8 N / m, and compared with the prior art, the reversed-phase suspension polymerization aqueous binder for the lithium battery has remarkable progress.

The invention belongs to the field of pharmaceutic adjuvants, and particularly relates to a method for preparing sodium polystyrenesulfonate resin through a centrifugal interfacial membrane emulsification technology and application of the sodium polystyrenesulfonate resin. The method comprises the following steps: by taking a mixed solvent of styrene, divinylbenzene and benzoyl peroxide as a dispersion phase and a polyvinyl alcohol solution as a continuous phase, carrying out centrifugal interfacial membrane emulsification, then carrying out suspension polymerization reaction to obtain polystyrene-divinylbenzene microspheres with narrow particle size distribution, and finally, carrying out sulfonation reaction and alkali exchange to obtain the polystyrene-divinylbenzene composite microsphere. The final product sodium polystyrenesulfonate resin is obtained. The resin prepared by controlling the centrifugal rotating speed, the centrifugal time and the using amount of the dispersing agent, the cross-linking agent and the sulfonating agent and combining a centrifugal interfacial membrane emulsification technology is in a dry golden brown powder shape, the average particle size is 60-100 microns after the resin is dispersed in water, and particles of the resin are uniformly distributed and are of a spherical structure. Meanwhile, the preparation method is simple in preparation process, short in operation time, low in energy consumption, good in economic benefit, suitable for industrial production and wide in market application prospect.

The present invention provides a rubber microcapsule, its preparation method, and application, belonging to the field of polymer material technology. The rubber microcapsule of the present invention has a core-shell structure, wherein the shell is polystyrene and the core is liquid nitrile rubber dispersed with coated sulfur; the coated sulfur is sulfur coated with polystyrene on the surface; and the liquid nitrile rubber contains reactive end groups. By mixing the coated sulfur with the nitrile rubber containing reactive end groups and then coating the rubber particles with a polystyrene layer through suspension polymerization, rubber microcapsules with excellent toughening effects are produced. Epoxy resin compositions toughened with the rubber microcapsules exhibit excellent toughness, strength, and thermal properties.

Expandable styrene polymers comprising polymeric brominated flame-retardant, wherein the polymeric brominated flame-retardant comprises at least one brominated polybutadiene block having a bromination degree between 33 and 75%, based on the double bonds in the polybutadiene block before bromination, a process for producing such expandable styrene polymers by suspension polymerization and particulate foam moldings made therefrom.

The invention relates to the technical field of high polymer materials, and discloses a submicron thermal expansion microsphere and a preparation method thereof. A micro-suspension polymerization system is adopted, and a reversible addition fragmentation chain transfer polymerization technology is applied to prepare the submicron thermal expansion microsphere with an alkane foaming agent core material wrapped by a modified inorganic particle / polymer composite shell layer. On the basis of the dispersion and stabilization mechanism of inorganic particles on oil-phase liquid drops, the interface desorption energy of the inorganic particles is improved by modifying the surfaces of the inorganic particles, and alkene double bonds are introduced, so that covalent connection between the inorganic particles and an organic shell layer in the polymerization process is realized, and the stable submicron thermal expansion microspheres are obtained; and a regular and uniform chemical crosslinking shell structure is constructed by combining a reversible addition fragmentation chain transfer polymerization technology, so that the problem that the shell of the microsphere becomes thin and is easy to break due to reduction of the particle size under the same core material loading capacity is solved, and the preparation method has a wide application prospect.

The application discloses a polypropylene-based energy storage dielectric material and a preparation method and application thereof. The preparation method comprises the following steps: after a polypropylene substrate and a (meth) acrylic acid fluorine-containing ester monomer are pre-swollen in a solvent, polymerization reaction is carried out through an initiator, and post-treatment is carried out on a grafted polymer to obtain a (meth) acrylic acid fluorine-containing ester functionalized polypropylene. The application adopts a suspension polymerization method, introduces a fluorine-containing group into a polypropylene structure to induce electron cloud distribution, promotes crystalline domain aggregation to improve crystallinity, adjusts dielectric constant, loss factor, leakage current and breakdown electric field of a polymer material, so that energy storage density and efficiency of a polymer dielectric are controlled.

A process for preparing an ethylene polymer in a suspension polymerization including the steps of separating the formed suspension of ethylene polymer particles in a solid-liquid separator into ethylene polymer particles and mother liquor, transferring a first part of the mother liquor into a work-up section including an evaporation unit for producing a wax-depleted portion of the mother liquor, wherein a protic agent is added to the part of the mother liquor which is transferred into the work-up section, and recycling a first part of the wax-depleted portion of the mother liquor to the polymerization reactor or the series of polymerization reactors.

The invention discloses an irradiation cross-linked biodegradable composite plastic straw and a preparation method thereof. The irradiation cross-linked biodegradable composite plastic straw is prepared from the following raw materials in percentage by mass: 40-80% of polylactic acid, 15-45% of nano inorganic filler, 0.4-1% of chain extender, 1-3% of flexibilizer, 1-3% of lubricant, 0.3-1% of nucleating agent, 0.3-1% of coupling agent, 1-10% of cross-linking agent and 0.3-1% of compatilizer. The chain extender is an epoxy group chain extender copolymer which contains 6-9 epoxy functional groups and is formed by copolymerizing glycidyl methacrylate, styrene and acrylic acid low-carbon alcohol ester through a solution polymerization or suspension polymerization process. The heat resistance of the polylactic acid composite plastic can be improved through irradiation processing, the polylactic acid composite plastic straw has higher heat resistance and does not deform in a high-temperature use environment, and pathogenic bacteria and viruses in a product are killed in the irradiation crosslinking process at the same time.

The application provides a preparation method of a rare earth metal adsorption and separation resin and a resin extraction column. The preparation method comprises the following steps: adding an oil phase composed of styrene, divinylbenzene, a pore former and an initiator into an aqueous phase containing a dispersant and an inorganic salt to perform suspension polymerization, so as to obtain a white ball resin; performing phthalimide and hydrolysis on the white ball resin, so as to obtain a primary amine resin; performing reaction on the primary amine resin with chloroacetic acid and an alkaline medium, so as to perform carboxymethylation on part of the primary amine sites; and performing reaction on the obtained intermediate resin with phosphorous acid, formaldehyde and an acidic medium, so as to perform phosphonic acid methylation on the remaining part of the primary amine sites. The white ball resin is first subjected to amination, and then part of the carboxymethylation and part of the phosphonic acid methylation are sequentially performed, so that the carboxyl type chelation sites and the phosphonic acid type chelation sites are simultaneously reserved in the same resin bead, thereby being beneficial to improving the comprehensive adsorption performance and separation performance of the resin on the rare earth metal.

The invention provides spherical lignin-phenolic resin, a preparation method thereof and application of the spherical lignin-phenolic resin in adsorption of N-containing organic dye, and belongs to the technical field of adsorption materials. The lignin-phenolic resin with the regular spherical morphology can be prepared through a one-step condensation polymerization reaction by taking lignin, hydroquinone and trioxymethylene as raw materials under an acidic catalysis condition and adopting a reversed-phase suspension polymerization method, the lignin belongs to a renewable resource and has the characteristics of low cost and environmental friendliness, and the lignin-phenolic resin can be used for preparing the lignin-phenolic resin with the regular spherical morphology. The phenolic resin can replace phenols to become a main phenol source, the substitution rate can reach 75%, and the yield of the synthesized phenolic resin reaches up to 60-80%. Besides, abundant phenolic hydroxyl groups, sulfonic acid groups and other oxygen-containing groups can be introduced into the resin by selecting the types of monomers, the cross-linked structure of the resin is changed by regulating and controlling the proportion of the monomers, the adsorption capacity of N-containing organic dyes is effectively improved, and efficient adsorption of rhodamine B and methylene blue can be achieved.

This utility model discloses a polyvinyl chloride suspension polymerization reactor, relating to the field of polymerization reactor technology. It includes an outer reactor body with a connecting frame on its annular side. A right-angle gear is rotatably connected inside the connecting frame, and a connecting block is fixedly connected to the lower surface of the connecting frame. An inner reactor body is rotatably connected inside the outer reactor body. During the stirring process, the output shaft of a servo motor drives the fixed right-angle gear to rotate. The rotation of the right-angle gear causes the inner reactor body, which is engaged with it, to rotate as well. The inner reactor body is rotatably mounted inside the outer reactor body via two fixed connecting rings. At this time, the rotation direction of the inner reactor body is opposite to that of the stirring rod. This interaction allows the materials to be subjected to forces in different directions, resulting in more thorough mixing and effectively improving the polymerization reaction effect.

The invention discloses an adsorbent resin and a preparation method thereof, and belongs to the technical field of wastewater adsorption treatment. The preparation method comprises the following process steps: S1, taking p-chloromethyl styrene, styrene and n, n '-(4, 4'-methylene diphenyl) bismaleimide as monomers, mixing the monomers, a cross-linking agent and a pore-foaming agent to obtain an oil phase, and carrying out suspension polymerization in the presence of a dispersion phase, an additive and an initiator to obtain a polymerization product; s2, carrying out Soxhlet extraction and other treatments on the polymerization product to obtain chloromethylated amide group modified polystyrene; s3, carrying out amination treatment on the chloromethylated amido group modified polystyrene to obtain an amination product; and S4, washing and vacuum drying the amination product obtained in the step S3 to obtain the adsorption resin. The adsorbent resin obtained by the method can effectively enrich long-chain alkyl carboxylic acid in a water body, and has the advantages of low cost, high adsorption capacity, strong selectivity and excellent cyclic regeneration stability.

The invention provides a micro-capsule suspending agent containing fluopyram as well as a preparation method and application of the micro-capsule suspending agent, and belongs to the technical field of pesticide preparations. The micro-capsule suspending agent containing fluopyram is obtained by adopting a suspension polymerization method, and the obtained micro-capsule suspending agent is high in encapsulation efficiency and excellent in dispersity, has good ultraviolet stability and heat storage stability, and has a good prevention and removal effect and a long lasting period when being used for preventing and treating root nematodes. After root-irrigation pesticide application, the micro-capsule suspending agent containing fluopyram provided by the invention can be slowly released in soil and roots, has a good prevention effect on tomato and cucumber root-knot nematode, and has the advantages of long lasting period, multiple prevention and control crops, wide bactericidal spectrum and excellent uptake conductivity.

The application discloses a polymer microsphere containing a surfactant unit. The polymer microsphere is prepared by a suspension polymerization method, and the polymer microsphere comprises the following units: A, an oil phase unit; B, a reactive surfactant unit; and C, an initiator unit. The application replaces a conventional surfactant with a reactive surfactant, and the amount of the reactive surfactant is smaller than that of a non-reactive surfactant. In addition, a suitable type of the reactive surfactant makes the microsphere dispersion more stable in the polymerization process, so that the polymer microsphere has a more concentrated particle size distribution, a smooth surface and excellent heat resistance. Meanwhile, the polymer microsphere disclosed by the application does not contain silica or residual suspending agent, and does not affect the application field of the polymer microsphere, so that the polymer microsphere has a greater application prospect in technical fields such as electronics, optoelectronics, optics, medicine and building.

This invention relates to a suspension polymerization method for polymerizing alkoxyamines with styrene and (meth)acrylic acid monomers, to beads and compositions thus obtained, and to uses of such beads and compositions.

The invention discloses a preparation method of through hole type resin, and belongs to the technical field of polymer resin materials. A ternary composite pore-foaming agent composed of toluene, n-heptane and polyethylene glycol (PEG) is adopted, the proportion of the ternary composite pore-foaming agent is optimized, and the through type resin is prepared through suspension polymerization and temperature programming curing. The resin prepared by the method has a highly through pore channel network, the penetration rate is not less than 50%, the resin also has appropriate large pore diameter and relatively high specific surface area and pore volume, meanwhile, the resin keeps good mechanical stability while obtaining an excellent penetration structure, the preparation process is good in repeatability, and the preparation method is suitable for industrial production. An ideal material is provided for the fields of high-performance adsorption separation, chromatographic analysis, catalysis and the like.

The present invention provides organic particles with high solvent resistance, which are made from a polymer having a main skeleton of cis-1,4-polyisoprene, a typical example of which is natural rubber. [Solution] A method for producing organic particles includes the steps of dissolving a polymer having cis-1,4-polyisoprene as a main skeleton in a solvent and carrying out a cyclization reaction to obtain a cyclized rubber having a cyclization rate of 60 to 90%, and suspension polymerizing the cyclized rubber and a vinyl monomer in the presence of water and a suspension stabilizer, wherein the polymer having cis-1,4-polyisoprene as a main skeleton has a Mooney viscosity [ML(1+4)100°C] specified in JIS K 6300 of 18 to 65, and the vinyl monomer contains a monofunctional vinyl monomer having only one vinyl group and a crosslinkable vinyl monomer having multiple vinyl groups.

Provided are methods for efficiently producing porous particles and a carrier for purification or adsorption which have excellent antifouling properties or excellent carbon dioxide adsorption properties.　A method for producing porous particles includes steps (i) to (iii) mentioned below, wherein the water-based medium in step (iii) is a water-based medium such that the amount of a salt dissolved per unit mass is 10 parts by mass or more when the mass of the salt per unit mass in a saturated solution reached by dissolving the salt in the water-based medium under conditions of 23°C and 1 atm is 100.　(i) A step for preparing a hydrocolloid in a salt-containing water-based medium; (ii) a step for dispersing a liquid composition in a hydrocolloid-containing water-based medium prepared in step (i), the liquid composition containing a hydrophobe having a solubility in water at 25°C of 1.0×10-4g / L or less and one or more monomers that are different from the hydrophobe; and (iii) a step for subjecting the monomers dispersed in step (ii) to suspension polymerization in a water-based medium containing a hydrocolloid and a salt.

The present invention belongs to the technical field of polymer materials, and specifically relates to a reactive vinyl chloride polymer and a preparation method thereof. Conventional toughening modifiers such as MBS, EVA, and CPE can all toughen and modify PVC, but the resulting PVC products have a relatively low Vicat softening point and hardness, and are prone to deformation after long-term use. In response to the above problems, the present invention provides a reactive vinyl chloride polymer, which uses vinyl chloride as a main monomer and vinyl acetate, a silane coupling agent, and an acrylate with a low glass transition temperature as auxiliary monomers. A vinyl chloride polymer with a low glass transition temperature, a wide molecular weight distribution range, and a reactive group alkoxysilane is obtained through suspension polymerization, which takes into account the performance requirements of impact resistance, tensile yield strength, Vicat softening point, and flexural modulus. It can not only be used as a processing aid modifier to achieve a better plasticizing effect, but also make the cost advantage of the resulting PVC products more prominent.

To provide a method for producing a resin which improves drying efficiency of a solvent, and can enhance productivity of an optical film.SOLUTION: A method for producing a resin including a structural unit derived from α-methylene lactone, and a structural unit derived from alkyl (meth)acrylate includes a polymerization step of suspending and polymerizing a monomer containing the α-methylene lactone and the alkyl (meth)acrylate in a solvent, in the presence of a first polymerization initiator, a second polymerization initiator and an emulsifier, wherein a 10-hour half-life temperature T2 of the second polymerization initiator is higher than a 10-hour half-life temperature T1 of the first polymerization initiator by 10°C or higher, and the polymerization step includes a first temperature holding step of holding the temperature of a reaction liquid to be suspended and polymerized at T1±10°C, and starting the polymerization, and a second temperature holding step of raising the temperature of the reaction liquid by polymerization heat, then holding the temperature of the reaction liquid at a temperature higher than the temperature of the reaction liquid in the first temperature holding step by 10°C or higher, and further polymerizing the reaction liquid.SELECTED DRAWING: None

The invention discloses a preparation method of in-situ large-size high-density semiconductor-grade high-purity silicon carbide multi-crystal grains, and relates to a preparation method of a high-purity semiconductor-grade silicon carbide polycrystal material. The method aims at solving the technical problems that silicon carbide polycrystalline particles prepared by an existing method are small, secondary crystallization is needed, energy consumption is high, and the yield is low. The method comprises the following steps: preparing precursor resin as a nucleation seed crystal and an adhesive by adopting a non-catalytic suspension polymerization method; 2, preparing a silicon-carbon pre-sintered body; and 3, preparing the in-situ large-size high-purity semiconductor-grade silicon carbide polycrystalline material through a curing process, a self-propagating synergistic carbon thermal reduction reaction process, an in-situ silicon carbide grain growth process and an in-situ silicon carbide grain densification process. The particle size of the prepared silicon carbide multi-crystal grains is 0.8-20mm, the purity reaches 6N, the density reaches 1.6-2.5 g / cm < 3 >, the yield is 85-90%, and the silicon carbide multi-crystal grains can be used in the field of silicon carbide preparation.