36 results about "Dimethylsilane" patented technology

Disclosed in the present invention are a fluorosilicone-modified low-surface-energy antifouling coating and a preparation method therefor. The coating comprises the following components in parts by weight: 11-15 parts of butyl acrylate, 3-4 parts of dodecafluoroheptyl methacrylate, 3-4 parts of vinyl-terminated polydimethylsiloxane, 3-4 parts of 2-hydroxy-4-acryloyloxybenzophenone, 30-38 parts of methyl isobutyl ketone, 0.15-0.25 parts of azobisisobutyronitrile, 0.1-0.2 parts of sodium hydroxide, 2-3 parts of modified titanium dioxide nanoparticles, and 0.5-1.5 parts of 3-aminopropyltriethoxysilane. In the present invention, vinylpentamethyldisiloxane reacts with decamethylcyclopentasiloxane to prepare vinyl-terminated polydimethylsiloxane; a titanium dioxide precursor is mixed with polydopamine nanoparticles for modification to prepare modified titanium dioxide nanoparticles; and then the components above are mixed to prepare the fluorosilicone-modified low-surface-energy antifouling coating. The coating has low surface energy and good adhesion and ultraviolet resistance.

The invention discloses a low-dielectric optical transparent adhesive film and a preparation method thereof, and relates to the field of adhesive films. When the low-dielectric optical transparent adhesive film is prepared, nano silicon dioxide sequentially reacts with 2-(4-chlorosulfonylphenyl) ethyltrimethoxysilane and 2, 2 ', 4, 4'-tetrahydroxybenzophenone, and modified silicon dioxide is prepared; the modified silicon dioxide, 4-vinylpyridine, allyltrimethoxysilane, 2-ethylhexyl acrylate, butyl acrylate, hydroxyethyl acrylate, diallyl phosphate and isophorone diisocyanate are subjected to a reaction, then ferric chloride is added, a polytetrafluoroethylene plate is coated and cured, and an adhesive film matrix is prepared; and carrying out surface treatment on the adhesive film substrate by using dimethoxydimethylsilane to prepare the low-dielectric optical transparent adhesive film. The low-dielectric optical transparent adhesive film prepared by the invention has flame-retardant, durable and waterproof capabilities.

The invention belongs to the technical field of polysulfide sealants, and relates to a bi-component modified polysulfide sealant for a binding surface as well as a preparation method and application of the bi-component modified polysulfide sealant. The bi-component modified polysulfide sealant for the binding surface is prepared from a component A and a component B according to the mass ratio of 100: (8-12), the component A comprises modified polysulfide rubber, a functional filler, a coupling agent, an adhesive and a regulator; the modified polysulfide rubber is prepared from polysulfide rubber and a modifier; the modifying agent is one of bis (2-chloroethyl) ether, 1, 2-dichloroethane and bis (chloromethyl) dimethylsilane; and the component B comprises a metal oxide, a plasticizer, an accelerant and a regulator. According to the modified polysulfide sealant formed by two components, the elongation at break of the polysulfide sealant is improved in an extreme environment, the sealant has excellent deformation resistance, cracking, shrinkage and bonding failure of a sealant layer are avoided, and the sealing performance of a binding surface is improved.

The application belongs to the field of new daily chemical materials, and particularly relates to an oil control and moisture retention composition, which comprises PEG-7 glyceryl cocoate 0.5-1.5%, PCA sodium 0.1-1%, bis-PEG-18 methyl ether dimethyl silane 1-3%, sage leaf oil 0.005-0.02%, and verbena oil 0.005-0.02%. The composition uses PEG-7 glyceryl cocoate, PCA sodium and bis-PEG-18 methyl ether dimethyl silane as main components, and uses sage leaf oil and verbena oil as oil components, so that the comprehensive oil control and moisture retention effect is achieved, the blood microcirculation and microecology of the scalp are improved, and the dandruff, oil control and moisture retention can be effectively achieved. Meanwhile, the application also provides the application of the composition.

The present application relates to the technical field of aircraft maintenance cleaning, and provides an aircraft surface salt removal and prevention cleaning agent and a cleaning method, the cleaning agent comprising the following components in percentage by mass: 0-30% of glycerol, 15-30% of a composite metal protective agent and 2-5% of an anti-salt protective agent, and the balance being distilled water, the composite metal protective agent comprising organic amine, organic acid, ethoxylated phosphate ester and benzotriazole, and the anti-salt protective agent comprising polydimethylsilane emulsion and potassium ferrocyanide; the cleaning agent effectively avoids the corrosion of salt water solution on the aircraft body material, especially metal material and metal plating, during the cleaning process, has good corrosion protection effect, and through the steps of rinsing and air drying or wiping, a protective film can be formed on the surface of the aircraft body, the crystallization of chlorides on the surface of the aircraft body is destroyed, the adhesion is reduced, the re-salting speed is effectively slowed down, and the cleaning agent is especially suitable for the salt removal and maintenance cleaning of military shipboard aircraft and near-shore military aircraft which are exposed to high-salt marine environment for a long time and have long-time low-altitude flight during flight.

The present invention relates to an oil-dispersed cosmetic composition having excellent suspension stability and, specifically, to an oil-dispersed cosmetic composition having excellent powder dispersibility, suspension stability, and formulation stability by optimally mixing a hydrogenated castor oil / sebacic acid copolymer as an oil thickener and silica dimethylsilylate as a dispersant.

The invention discloses medical liquid silica gel and a preparation method thereof, and relates to the technical field of silica gel materials. The method comprises the following steps: drying vinyl-terminated polydimethylsiloxane with a side chain containing vinyl, and carrying out addition reaction on part of polydimethylsiloxane and dehydrated 1H, 1H, 2H, 2H-perfluorodecyl dimethyl silane to obtain a fluorine-containing modified liquid silica gel matrix; the preparation method comprises the following steps: coating dopamine-coated nano-diamond with a silicon dioxide layer, and then grafting vinyl trimethoxy silane and octyl triethoxy silane, so as to prepare a modified wear-resistant filler; the preparation method comprises the following steps: mixing a fluorine-containing modified liquid silica gel matrix, a modified wear-resistant filler, vinyl MQ silicon resin and a catalyst to prepare a component A; mixing the residual dry base rubber with hydrogen-containing silicone oil and 3-methyl-1-butyne-3-alcohol to prepare a component B; and finally, mixing and curing the component A and the component B. The prepared liquid silica gel has excellent wear resistance and mechanical properties, and is suitable for the field of medical apparatuses and instruments.

This invention provides a composite flame-retardant material formed by combining organosilicon resin and hybrid flame-retardant particles. The organosilicon resin is formed by the hydrolysis and condensation of a mixture of organosilicon monomers. The organosilicon monomer mixture includes monomethylsilane monomer, dimethylsilane monomer, monophenylsilane monomer, and diphenylsilane monomer. The hybrid flame-retardant particles include nanoparticles modified with a mercaptosilane coupling agent. The surface of the mercaptosilane coupling agent-modified nanoparticles is grafted with phosphonic acid groups. Compared with the prior art, this invention introduces phosphorus by grafting phosphonic acid groups onto the surface of the mercaptosilane coupling agent-modified nanoparticles, thereby improving the flame-retardant performance by combining phosphorus with silicon, while reducing the silicon content and avoiding its impact on mechanical properties. This allows the composite flame-retardant material to be used for surface flame retardancy of polyurethane materials, improving their flame-retardant efficiency and smoke suppression effect without affecting the inherent properties of the polyurethane material.

This invention discloses a moisture-proof and dust-proof epoxy paint and its preparation method, belonging to the field of coating technology. The moisture-proof and dust-proof epoxy paint disclosed in this invention, by weight, comprises the following raw material components: 100 parts by weight of high-temperature resistant epoxy resin, 0.8-1.2 parts by weight of curing agent, 8-12 parts by weight of waterproof silicone resin, 4-6 parts by weight of defoamer, 5 parts by weight of leveling agent, 10-15 parts by weight of solvent, and 1-3 parts by weight of antistatic agent. The high-temperature resistant epoxy resin is obtained by epoxidation after grafting 1-bromo-4-(trifluorovinyloxy)benzene, cashew nut shell powder, and hexachlorocyclotriphosphazene. The waterproof silicone resin is obtained by polycondensation of 3-glycidyl etheroxypropyltriethoxysilane and tetraethyl orthosilicate followed by end-capping with 4-[trifluorovinyl(oxy)phenyl]dimethylsilane.

The application relates to the technical field of composite materials, and particularly relates to a silicon carbide fiber composite core wire and a preparation method. Dimethyldichlorosilane is obtained to carry out dechlorination polymerization, polydimethylsilane is generated, high-temperature and high-pressure cracking rearrangement is carried out, and polycarbosilane is obtained; the polycarbosilane is melted and extruded through a spinning hole to obtain continuous polycarbosilane original fibers, the continuous polycarbosilane original fibers are crosslinked to obtain crosslinked fibers, high-temperature cracking is carried out, and the crosslinked fibers are converted into inorganic silicon carbide fiber bundles; the silicon carbide fiber bundles are immersed in a high-temperature resistant resin glue solution and enter a heated pultrusion mold to be pultruded into a silicon carbide fiber composite core rod; inner layer aluminum wires are twisted outside the silicon carbide fiber composite core rod, and outer layer aluminum wires are twisted outside the inner layer aluminum wires to obtain the silicon carbide fiber composite core wire. The prepared composite core wire has the outstanding advantages of high strength, high modulus, high-temperature resistance, oxidation resistance, corrosion resistance, a low thermal expansion coefficient and large conveying capacity, and has important economic benefits in power transmission line capacity increasing and reconstruction projects.

The application discloses a preparation method of a photocurable rare earth doped low-oxygen silicon carbide fiber, and comprises the following steps: preparing liquid sol A by taking a rare earth metal organic complex and polydimethylsilane as raw materials; obtaining a polycarbosilane precursor B containing a rare earth metal element by evaporating a solvent and high-temperature cracking reaction of the sol A; then preparing modified polycarbosilane by blending reaction of the polycarbosilane precursor B and an unsaturated organic ether; and then performing infusibilization treatment on the modified polycarbosilane by ultraviolet light irradiation under the action of a photoinitiator after melt spinning; and finally obtaining the rare earth doped low-oxygen silicon carbide fiber after high-temperature sintering treatment. f The rare earth element is introduced in the preparation of the precursor, and the rare earth element is uniformly dispersed in the silicon carbide crystal lattice, and the silicon carbide original wire is subjected to infusibilization crosslinking treatment by combining photo-curing, so that the crystal growth and electromagnetic properties of the ceramic can be better improved while the oxygen content of the silicon carbide fiber is reduced.

The invention provides high-purity polydimethylsilane and a preparation method thereof, and the preparation method comprises the following steps: adding dimethyldichlorosilane and alkali metal into a benzene solvent under the protection of inert gas, and reacting at high temperature to obtain a product; adding alcohol into the product, neutralizing unreacted raw materials, and then filtering to obtain crude polydimethylsilane; providing a cleaning container provided with two layers of filter screen assemblies, and adding the crude polydimethylsilane between the two layers of filter screen assemblies; a cleaning solvent is added into the cleaning container to be higher than the upper-layer filter screen assembly, and cleaning is conducted; a part of liquid in the cleaning container is discharged from the upper part of the upper-layer filter screen assembly, and then the residual liquid is discharged from the lower part of the lower-layer filter screen assembly; and repeating for multiple times, and finally evaporating to obtain the high-purity polydimethylsilane. According to the method, the content of oxygen-containing silane, chloride ions and alkali metal ions in the polydimethylsilane can be reduced, and the high-purity polydimethylsilane with the oxygen content lower than 0.5%, the chloride ion content lower than 20 ppm and the alkali metal ion content lower than 20 ppm is obtained.

A method for forming polycarbosilanes used as precursors for producing silicon carbide fibers or composites includes providing poly(dimethylsilane) (PDMS) as a solid, providing a catalyst, which includes phenylboronic acid or boric acid, and reacting the solid PDMS with the catalyst at a temperature of about 340oC for a sufficient period of time to form the polycarbosilanes. Alternatively, the method may include providing a liquid silane formed from PDMS and heating the liquid silane and the catalyst at a temperature ranging from about 100oC to about 200oC for about 1 to about 2 hours. After heating, reacting the liquid silane with the catalyst at a temperature ranging from about 220oC to about 340 oC for a sufficient period of time to form the polycarbosilanes. The ceramic yield for the synthesized polycarbosilanes is in the range between about 60% to about 74% under inert gas upon heating to 1000oC.

The present application uses the mixture of residual liquid and cracking product (LPS) after the cracking of polydimethylsilane (PDMS) as raw material, and the polymerization reaction with tributyl borate or triethyl borate obtains viscous liquid (LPCS), which introduces the heterogeneous element boron; the viscous liquid (LPCS) further reacts with zirconium acetylacetonate to introduce the heterogeneous element zirconium, and the polycarbosilane ceramic precursor (PBZCS) doped with boron and zirconium elements is obtained; the precursor silk obtained after the melt spinning can be inosculated by the relatively simple air oxidation crosslinking method, and the boron and zirconium elements act as sintering agents to densify the fiber in high-temperature sintering, and the high-temperature-resistant ceramic fiber is obtained.

The invention provides a method for preparing a sorafenib-cholic acid coupling prodrug based on step-by-step coupling of sorafenib modular assembly, which comprises the following steps of: firstly synthesizing a complete sorafenib part by taking tert-butyl-(iodo-oxy) dimethylsilane as a linker, and after a sorafenib module is assembled, preparing the sorafenib-cholic acid coupling prodrug through step-by-step coupling, thereby obtaining the sorafenib-cholic acid coupling prodrug. And then coupling with cholic acid compounds step by step through deprotection. According to the method, the reaction steps are greatly reduced, the reaction can be carried out under the room temperature condition, the safety of the synthesis process is improved, especially depending on the unique connexon design and through the specific binding mechanism of the connexon and the sorafenib module, on one hand, the yield of each reaction step is remarkably improved, and on the other hand, the yield of the sorafenib module is greatly increased; the preparation efficiency of a target product is greatly improved; and on the other hand, side reaction is blocked from the reaction source, so that the purification difficulty of the product is reduced, and the controllability of the whole synthesis process is enhanced.

The application discloses a skin-feeling acrylic finish emulsion and a preparation method and application thereof. The emulsion is prepared by emulsion polymerization of the following monomer components in a weight ratio: a) 15-70% of ester monomers, b) 1.3-10% of acetoacetoxy-containing olefinically unsaturated monomers, c) 0.5-5% of unsaturated hydrophilic monomers, d) 0.2-5% of reactive silane coupling agents, e) 10-50% of styrene, and f) 14-25% of (4-vinylphenyl)dimethylsilane. The acrylic finish emulsion provided by the application is applied to building interior wall coatings, has a smooth skin feeling, has good anti-graffiti performance, and has synergistically improved water resistance and scrub resistance.

The application discloses a kind of crosslinking strategy construction polymer conversion wave-absorbing ceramic and its preparation method and application, belong to ceramic technical field, solve the problem of uneven dispersion of material caused by the preparation method in the prior art.The method comprises the following steps: the hyperbranched polyborosilazane precursor containing silicon-hydrogen bond and poly(diacetylene) dimethylsilane containing alkyne group are uniformly dissolved in anhydrous tetrahydrofuran according to the mass ratio of 5-20:1, platinum (0) -1,3-divinyl-1,1,3,3-tetramethyldisiloxane is added, and the anhydrous tetrahydrofuran is removed after overnight reaction at 45-60℃ temperature condition, to obtain a polymer precursor;The polymer precursor is crosslinked at 400℃, ground into powder, pressed into embryo and pyrolyzed at 1400℃, to obtain a polymer conversion wave-absorbing ceramic.The preparation method provided by the application uniformly mixes and crosslinks two kinds of polysilane at the molecular level to obtain a new polymer precursor, and pyrolyzes at high temperature to prepare a wave-absorbing ceramic with uniform dispersion of structural components, achieving a more stable effect.

The application relates to the technical field of release agents, and discloses a water-based release agent for polyurethane foaming of automobile seats, which is prepared by stirring polydimethylsilane, octamethyltetrasiloxane, deionized water, polyoxyethylene polyethylene glycol carboxylate and propylene glycol at a speed of 600-800 r / min for 3-6 min under room temperature conditions, continuously adding modified carbon nanotubes and double-end epoxy silicone oil, and stirring at a speed of 1000-1500 r / min for 4-7 min. The water-based release agent for polyurethane foaming of automobile seats has good release effect.

The utility model discloses a multifunctional rotating shaft turning gear for a stirring kettle in a polydimethylsilane production line, which is mounted on a rotating shaft of the stirring kettle and structurally comprises a handle and a ratchet head, a lower half gear and an upper half gear are arranged in the ratchet head, the upper half gear is positioned above the lower half gear, and the upper half gear is positioned above the lower half gear. When the upper half gear and the lower half gear are buckled on the rotating shaft of the stirring kettle, the upper half gear and the lower half gear are fastened and connected through a gear connecting bolt; the two sides of the ratchet wheel head are respectively connected with two limiting rods which are oppositely arranged, the two limiting rods are respectively connected with the side wall of the ratchet wheel head through elastic pieces, and a reversing shifting piece is arranged in the middle of the ratchet wheel head and located between the two limiting rods. After the technical scheme is adopted, the one-way rotating function is designed, so that the reverse rotation of the rotating shaft of the stirring kettle can be avoided, the risks of equipment damage and personnel injury caused by improper operation are reduced, and the safety in the maintenance process is guaranteed.

The application discloses a photosensitive benzocyclobutene-based polycarbosilane based on internal alkyne silicon hydride polymerization, preparation and application in advanced packaging, and relates to polycarbosilane obtained by a silicon hydride polymerization reaction of benzocyclobutene-based internal alkyne monomers and 1,4-di(dimethylsilyl)benzene; the polycarbosilane, a photo-crosslinking agent, a photo-initiator and an organic solvent are compounded to obtain a photoresist. The photoresist is further used as a high-performance dielectric material, realizes high-density and high-performance re-routed layers in advanced packaging, and is one of key materials supporting the development of advanced packaging technology, and therefore plays an indispensable role in frontiers such as high-performance computing and artificial intelligence, high-end communication and radio frequency, heterogeneous integration and chip grain design, image sensor and micro-electro-mechanical system.

The application discloses a kind of fire material evidence transportation violence sorting and high temperature early warning flexible material preparation method, belong to judicial material evidence circulation field and logistics transportation field, comprising: step 1: indium-gallium alloy liquid metal is added to container, pour into ethanol aqueous solution, fully stir, drop into dopamine hydrochloride solution, adjust pH value to 7.5~9.0, stir at room temperature;Dropping into acetone settlement to reaction liquid, centrifugal, filtration, filter cake is washed after stirring with acetone and natural drying, obtain polydopamine coated liquid metal;Step 2: take (4-vinylphenyl) dimethyl silane, acrylic acid ester group p-benzoic acid, 1-vinyl-3-butyl imidazole hexafluorophosphate, dissolved in dichloromethane to make solution, add photoinitiator Irgacure-2959, add polydopamine coated liquid metal, material is fully stirred after pouring into polytetrafluoroethylene mold, under 650W ultraviolet lamp, light initiation polymerization, solvent is dried to constant weight, obtain fire material evidence transportation violence sorting and high temperature early warning flexible material.

The invention belongs to the technical field of lithium ion batteries, and particularly relates to application of a functional electrolyte containing bis (2-fluoroethoxy) dimethylsilane (F2DEO). The electrolyte with the wide temperature range, the high voltage and the high rate performance comprises F2DEO and lithium salt, or a cosolvent and an additive are added. The problems that an existing commercial electrolyte is poor in high and low temperature performance, poor in high voltage performance, poor in rate capability, poor in compatibility with lithium metal and the like are solved in a targeted mode. The electrolyte provided by the invention shows excellent cycle performance and rate capability in LiNCM811, LiLFP, LiLCO, LiGraphite and LCOGraphite batteries, is far superior to commercial electrolyte or other reported electrolyte, and effectively promotes the development of lithium batteries which stably operate under the conditions of high energy density and wide temperature range. The invention includes but is not limited to lithium ion batteries, and is also applicable to the fields of potassium ion batteries and sodium ion batteries.

The application discloses a self-assembled forming high-efficiency radiation refrigeration fabric and a preparation method thereof. The high-efficiency radiation refrigeration fabric is obtained by introducing calcium vanadinite nanoparticles as inorganic fillers into a polymer matrix by using a sol-gel solution spinning technology, wherein the polymer matrix is formed by polymerization of polyvinyl butyral and polydimethylsilane. The preparation method directly integrates the radiation cooling technology into various applications through the hierarchical multi-level design of the random distribution and the synergistic scattering of the soft fiber and the hard skeleton fiber fabric design. The preparation process is simple, easy to operate, low in preparation cost, high in efficiency and easy for industrialized production. The prepared layered fabric microfiber structure can be cut into any required shape. Moreover, the layered fabric microfiber structure has good radiation refrigeration, flexibility, self-cleaning and mechanical properties, is suitable for various application scenarios and solves the problems of poor radiation refrigeration efficiency, poor cleaning capacity, complex process and application limitation of the existing radiation refrigeration.

The invention provides a coated liposome as well as a preparation method and application thereof, and belongs to the technical field of cosmetics. Comprising the following steps: (1) mixing ceramide 3, dimer dilinoleate and cholesterol, heating for melting, cooling, adding ergothioneine, and stirring and mixing to obtain an oil phase; (2) heating, stirring and mixing polyquaternium-51, bis (lauramide glutamine) sodium lysine, sodium hyaluronate, glycerol and water to obtain a water phase; (3) under a heating condition, adding the oil phase into the water phase in a trickle form, and performing ultrahigh-pressure microjet homogenization; and (4) the temperature is controlled, the speed is reduced, the temperature is reduced, the bis-PEG-18 methyl ether dimethylsilane and the pre-dispersed sodium polyacryloyldimethyl taurate are added, the materials are stirred and mixed, the coated liposome is obtained, the coated liposome is not turbid after being added into an aqueous solution, the coated liposome has good high and low temperature resistance stability, and the effects of improving skin targeted delivery and repairing skin barriers are achieved.

This invention provides a flexible functional composite material with excellent thermal management capabilities and its preparation method. It mainly comprises the following key components: a polydimethylsilane (PDMS) matrix material, a hexagonal boron nitride (h-BN) thermally conductive material, and a microencapsulated phase change microsphere (MPCM) thermal storage material with melamine-formaldehyde resin as the shell and n-eicosane as the core material. The preparation method involves only simple stirring, heating, and curing, and based on the crosslinking inhibition mechanism and external force constraints, it is possible to prepare flexible functional composite materials with high filler concentrations. The flexible functional composite material of this invention exhibits excellent mechanical and thermal management properties. The thermally conductive phase material can rapidly transfer heat flow, improving the heat absorption efficiency of the thermal storage phase material, while the thermal storage phase material can rapidly absorb heat, promoting temperature reduction. This invention is simple to prepare and has superior performance, showing promising application prospects in fields such as electronic skin, electronic devices, and advanced fabrics.

The invention provides a flexible functional composite material with excellent heat management capability and a preparation method thereof. The flexible functional composite material mainly comprises the following important components: a polydimethylsilane (PDMS) matrix material, a hexagonal boron nitride (h-BN) heat conduction material, and a microcapsule phase change microsphere (MPCM) heat storage material taking melamine formaldehyde resin as a shell material and n-eicosane as a core material. The preparation scheme only comprises simple stirring, heating and curing, and preparation of the flexible functional composite material with high filler concentration can be realized based on a cross-linking inhibition mechanism and external force constraint. The flexible functional composite material has excellent mechanical properties and heat management performance, the heat conduction phase material can quickly transfer heat flow to improve the heat absorption efficiency of the heat storage phase material, and the heat storage phase material can quickly absorb heat to promote temperature reduction. The invention has the advantages of simple preparation and excellent performance, and has good application prospects in the fields of electronic skin, electronic equipment, advanced fabrics and the like.

The present application relates to a kind of containing lyophilization protectant efficacy lyophilized tablet and its preparation method and application, the efficacy lyophilized tablet includes ascorbic acid or its derivative, humectant, whitening agent, pH adjusting agent and lyophilization protectant;The lyophilization protectant includes the combination of polyethylene glycol, bis-PEG-18 methyl ether dimethyl silane, mannitol.The present application creatively adds lyophilization protectant in the lyophilized tablet of ascorbic acid or its derivative, can adjust the skin feel and solubility of lyophilized tablet whole while improving the appearance of lyophilized tablet using lyophilization mould, also can keep the stability of active substance in lyophilized tablet.Lyophilization protectant uses the combination of polyethylene glycol, bis-PEG-18 methyl ether dimethyl silane, mannitol, three mutually cooperate, synergistic effect, so that lyophilized tablet has excellent smooth feeling while improving toughness and hardness, improves the experience of using.

The invention discloses a method for continuously synthesizing polycarbosilane under high pressure, and relates to the field of materials and chemical engineering. The method comprises the following steps: heating and pyrolyzing polydimethylsilane (PDMS) to form liquid polysilane (LPS), pressurizing the LPS liquid through a pressurizing pump, continuously reacting in 3-10 tubular reactors which are connected in series and have gradually increased temperatures in sequence, and finally forming PCS to be discharged. According to the method, a continuous and high-pressure PCS production mode is adopted, and full-process continuous production is realized through a plurality of sets of PDMS pyrolysis equipment and PCS receiving tanks which operate alternately. The PCS yield is high, and the working condition is good. Large-scale autoclaves are avoided, and the service life of equipment is prolonged; the method is suitable for industrial mass production of the SiC ceramic fiber precursor.

Embodiments are directed to a method of making an olefin-based polymer by free-radical polymerization in a reactor system. The method includes initiating a free-radical polymerization of an olefin-based monomer, propagating growth of the olefin-based polymer during continued free-radical polymerization of the olefin-based monomer, and adding to the reactor system a chain transfer agent that terminates the growth of the olefin-based polymer. The chain transfer agent includes a silane. Examples of suitable silanes are: triethylsilane, diethylmethylsilane, tris(trimethylsilyl)silane, n-butylsilane, dimethylphenylsilane, phenylsilane, chlorodimethylsilane, diisopropylaminosilane, 1,2-bis(dimethylsilyl) benzene, 1,3-bis(dimethylsilyl) benzene, 1,4-bis(dimethylsilyl)benzene, 1,1, 3,3-tetramethyldisiloxane, trimethylsilane, (trimethylsilyl)dimethylsilane, and bis(trimethylsilyl)methylsilane.

The invention discloses narrow-distribution liquid rubber based on a high-steric-hindrance silane chain transfer agent and a preparation method of the narrow-distribution liquid rubber, and relates to the technical field of liquid rubber. Through the combination of specifically designed high-steric-hindrance adamantyldimethylsilane and the specific solvent, the technical problem that high-efficiency chain transfer and high-fidelity re-initiation are difficult to simultaneously realize in a low-cost chain transfer agent system is creatively solved, so that the production cost is remarkably reduced; and a high-performance liquid rubber product comparable with the traditional expensive n-butyllithium'pure 'living polymerization is obtained.