257 results about "Platinum catalyst" patented technology

The invention relates to the field of high polymer materials, and discloses a preparation method of high-temperature-resistant oil-resistant special functional silica gel, which comprises the following steps: adding a thermoplastic polyester elastomer, fluorosilicone rubber and a macromolecular compatilizer into an extruder through a main feeding port, and carrying out melt blending; adding hydrogen-containing silicone oil, a platinum catalyst and an internal closed type cross-linking agent through a side feeding port, and carrying out distributed blending; under the condition that the temperature is higher than the deblocking temperature of the cross-linking agent, initiating the internal closed cross-linking agent to perform physical thermal cracking shelling and release cross-linking sites, and guiding hydrosilylation reaction to perform dynamic vulcanization; and after vacuumizing and exhausting, extruding and pelletizing to obtain the silica gel. Through cooperation of a space-time decoupling distributed feeding process and a non-toxic thermal deblocking cross-linking agent, catalyst poisoning caused by early-stage high-temperature shear consumption and by-products is avoided, a cross-phase covalent interlocking network is constructed at a polyester and fluorine-silicon two-phase interface, permeation of a non-polar solvent is hindered, and therefore the performance of the fluorine-silicon copolymer is improved. The volume swelling ratio of the material is reduced; and the high-temperature aging resistance is improved.

The invention belongs to the technical field of hydrolysis hydrogen production, and particularly relates to a preparation method of a CoPx-CeO2 loaded platinum catalyst with a core-shell structure and application of the CoPx-CeO2 loaded platinum catalyst in seawater electrolysis hydrogen production. A Co (CO3) 0.5 (OH) nanorod precursor is prepared on foamed nickel through a hydrothermal method and then calcined to obtain CoPx, a CeO2 film is electrically deposited to obtain a CoPx-CeO2 composite carrier, and platinum is impregnated and loaded to obtain the CoPx-CeO2-Pt catalyst. The catalyst shows excellent hydrogen evolution catalytic activity in seawater, and the CoPx-CeO2 composite carrier prevents Pt nano-particles from being agglomerated through interaction of metal carriers, so that the atom utilization rate of Pt is increased. Meanwhile, the CeO2 film actively enriches OH <-> in an alkaline electrolyte to construct a local high-alkalinity microenvironment on the surface of the catalyst, Cl <-> in seawater is prevented from getting close to an active site corroding the catalyst through electrostatic repulsion, and the stability and durability of the catalyst are improved.

The present invention provides a method for manufacturing an adhesive member, comprising the steps of applying an ultraviolet-curable silicone composition containing (A) an organopolysiloxane containing an unsaturated group, (B) an organohydrogenpolysiloxane, and (C) an ultraviolet-activated hydrosilylated platinum catalyst having a cyclopentadienyl group to which a condensed aromatic hydrocarbon group is bonded as a ligand, to a first substrate layer, and including in any order: (i) bonding the first substrate layer to which the ultraviolet-curable silicone composition has been applied to a second substrate layer via a layer of ultraviolet-curable silicone composition; (ii) depressurizing the ultraviolet-curable silicone composition applied to the first substrate layer under a pressure below atmospheric pressure; and (iii) irradiating the ultraviolet-curable silicone composition applied to the first substrate layer with ultraviolet light. The invention also provides an adhesive made of a silicone composition with excellent curability, and an adhesive member with high adhesiveness and high reliability as a component.

The invention belongs to the technical field of coating materials, and particularly relates to an ablation-resistant anti-aging coating on the surface of an aircraft and a preparation method of the ablation-resistant anti-aging coating. A silane coupling agent containing an epoxy group and vinyl and boric acid are used as raw materials, an organic silicon-boron hybrid oligomer with a Si-O-Si and Si-O-B bond stereo structure is obtained by adjusting the ratio of the silane coupling agent to the boric acid and serves as a bridge, and phenolic resin, hydrogen-containing silane and vinyl silicone rubber are combined together to form the ablation-resistant anti-aging coating. Wherein an epoxy group and a phenolic hydroxyl group are subjected to a condensation reaction, vinyl and a platinum catalyst form a compact cross-linked structure through hydrogen-containing silane, and the obtained coating has a lower ablation rate, better anti-UV weather resistance and higher flexibility, is suitable for long-time protection of the surface of an aircraft, and has a better ablation protection effect under shear airflow impact.

The invention discloses a high and low temperature resistant organosilicon gel and a preparation method thereof, the organosilicon gel comprises a component A and a component B, the component A is prepared by mixing 100 parts of vinyl-terminated silicone oil and 0.05-0.2 part of a platinum catalyst, and the component B is prepared by mixing 50-70 parts of vinyl-terminated silicone oil, 20-40 parts of a chain extender, 5-15 parts of a cross-linking agent, 0.05-0.2 part of an inhibitor and 0.05-0.3 part of a heat-resistant additive. The organic silicon gel disclosed by the invention is low in viscosity, good in fluidity, colorless and transparent, good in flexibility and low stress after being cured, good in adhesion effect on various base materials, excellent in electric insulativity and high and low temperature resistance, capable of tolerating a high temperature of 240 DEG C for a long time, and free of chain segment crystallization behavior at a low temperature of-77 DEG C. The organic silicon gel is used for packaging protection of various different substrates and electronic components, the reliability and the service life of the components, high-power semiconductor modules and the like at high temperature can be remarkably improved, and the reliability of electronic equipment is guaranteed.

This invention relates to the field of potting compound technology, and more particularly to a thermally conductive potting compound, its preparation method, and its application method. The invention provides a thermally conductive potting compound comprising component A and component B; component A, by weight, comprises: 24-28 parts of thermally conductive base adhesive; 0.7-1.0 parts of vinyl silicone oil; 0.05-0.15 parts of platinum catalyst; and 0.04-0.12 parts of colorant; component B, by weight, comprises: 24-28 parts of thermally conductive base adhesive; 0-0.4 parts of vinyl silicone oil; 0.8-0.9 parts of hydrogen-containing silicone oil; and 0.005-0.015 parts of inhibitor; the inhibitor includes ethynylcyclohexanol and / or methylbutynol. The thermally conductive potting compound provided by this invention has ultra-high thermal conductivity, low volatility and low viscosity, excellent mechanical properties, excellent electrical insulation properties, and superior storage stability, exhibiting no clumping or agglomeration after 6 months of storage.

This application relates to the field of protective film materials technology, and discloses a weather-resistant and high-temperature-resistant silicone leather protective film and its preparation method. The weather-resistant and high-temperature-resistant silicone leather protective film of this application comprises a knitted fabric substrate layer and an organosilicon composite layer stacked sequentially from bottom to top; wherein, the raw materials of the organosilicon composite layer include: methyl vinyl silicone rubber, modified fumed silica, hydroxyl silicone oil, hydrogen-containing silicone oil, platinum catalyst, UV stabilizer, flame retardant, and antioxidant; the modified fumed silica is obtained by modifying fumed silica with a composite silane coupling agent, and the specific surface area of ​​the fumed silica before modification is 200~400 m² / g. 2 / g. The preparation method of this application is simple and efficient. Through the steps of substrate pretreatment, mixing of adhesives, composite molding, and post-treatment, the resulting weather-resistant and high-temperature resistant silicone leather protective film has excellent mechanical strength, weather resistance, high-temperature resistance, and flame retardant properties.

The present application relates to the technical field of catalytic hydrogenation reaction, and discloses a preparation method and application of an organic phosphine shell modified nanocatalyst, which comprises the following steps: adding a carbon carrier in an alcohol solvent and ultrasonic dispersion, then adding a chloroplatinic acid containing alcohol solution, and stirring at 0-15 DEG C; subsequently, an organic phosphine containing alcohol solution and a reducing agent are added, and the stirring is continued; finally, rotary evaporation is carried out, and drying is performed to obtain the nanocatalyst; the nanocatalyst is a platinum catalyst with a core-shell structure loaded on the surface of the carbon carrier. By introducing the organic phosphine ligand to the surface of the nanometer platinum particles, the core-shell structure nanoparticles with a flexible organic phosphine ligand modified shell are constructed, the adsorption and desorption strength and configuration of the active site electronic structure, the reaction microenvironment, the reactants and the intermediate state of the reaction interface are regulated, and the selective and efficient hydrogenation of the aromatic hydrocarbon containing nitro or carbon-carbon double bond is realized.

The application relates to the technical field of organic silicon synthesis, and particularly discloses a high-selectivity platinum catalyst and a vinyl double-seal head synthesis method. The high-selectivity platinum catalyst comprises a carrier and a platinum active component loaded on the carrier, the platinum active component is obtained by reducing and activating a platinum precursor and a ligand under a hydrogen atmosphere at 250-350 DEG C after coordination modification, and the molar ratio of the ligand to the platinum element in the platinum precursor is 2-3:1. In the application, the platinum active component is obtained by reducing and activating the platinum precursor and the ligand after coordination modification, and the ligand and the platinum element form a specific coordination structure of the platinum active center, guide the direct silicon-hydrogen addition reaction of acetylene and a hydrogen-containing double-seal head, thus the dimethyl chlorosilane intermediate is not needed, the process flow is simplified, and the effects of improving the reaction yield, environmental protection and process economy are achieved.

The application relates to the technical field of platinum catalysts, and particularly discloses an anti-yellowing platinum catalyst capable of prolonging the curing time and a preparation method thereof. The platinum catalyst comprises a platinum metal compound, an alkenyl-containing siloxane compound, an alkaline metal salt, an organic solvent and a catalyst carrier; wherein the mass ratio of the platinum metal compound, the alkenyl-containing siloxane compound, the alkaline metal salt and the organic solvent is 1:(8-20):(1.2-3):(6-20). The platinum catalyst has the advantages of being capable of prolonging the curing time and having the anti-yellowing performance, and has a wide application scenario.

The invention provides organic silicon leather with a Janus structure and a preparation method of the organic silicon leather. The preparation method comprises the following steps: S1, mixing diphenylmethane diisocyanate, polytetrahydrofuran ether glycol and dibutyltin for a first reaction, then adding 4-DOPO-(((3-hydroxypropyl) imino) methyl) phenol into a reaction system for a second reaction, and finally adding 3-perfluorohexyl-2-hydroxypropyl acrylate for terminating, so as to obtain a prepolymer; the polyurethane macromolecules containing fluorine and double bonds at the end are obtained; and S2, coating the surface of base cloth with the polyurethane macromolecule containing fluorine and double bonds at the end to form a bottom coating, then coating the surface of the bottom coating with hydrogen-containing silicone oil, vinyl silicone oil and a platinum catalyst, and carrying out hydrosilylation reaction through thermal induction treatment to form the organic silicon leather. According to the method, the hydrosilylation reaction is triggered through thermal induction, and the PU-PSi composite coating with the Janus structure is formed in situ. According to the method, no organic solvent is needed, the process is environment-friendly, and the obtained organic silicon leather has high bonding strength and excellent wear resistance, flame retardance and hydrophobicity.

This invention belongs to the field of catalyst technology, and discloses a high-efficiency platinum catalyst, its preparation method, and its application. The preparation of the high-efficiency platinum catalyst of this invention includes mixing and stirring a Karstedt catalyst, a ligand, and a catalyst, adding vinyl-terminated polydimethylsiloxane, and fully dissolving it to obtain the high-efficiency platinum catalyst. The obtained catalyst is used to prepare filler-free flame-retardant silicone rubber, which comprises the following raw materials in parts by weight: 80-100 parts vinyl-terminated polydimethylsiloxane, 2-4 parts crosslinking agent, 2-10 parts of the high-efficiency platinum catalyst of this invention, and 0.2-0.3 parts polymerization inhibitor. This invention provides a novel modified platinum catalyst for silicone rubber, which enhances the anti-sintering properties of Pt at high temperatures through the nitrogen-containing carbene ring and the Pt ligand, thereby improving the flame-retardant properties of silicone rubber brought by the platinum catalyst.

The application discloses a propargyl polysiloxane modified cyanate ester resin and a preparation method and application thereof, and comprises the following steps: S1, a propargyl compound shown in formula I and polysiloxane shown in formula II are subjected to a heating reaction in the presence of a platinum catalyst and a solvent to obtain a propargyl polysiloxane; S2, the propargyl polysiloxane is mixed with a cyanate ester monomer, heated and stirred until a transparent solution is obtained, and subjected to a heat curing treatment to obtain the propargyl polysiloxane modified cyanate ester resin. The propargyl polysiloxane modified cyanate ester resin can be cured and formed at a lower curing temperature, and the prepared modified resin has lower dielectric loss, water absorption, higher impact strength and thermal stability, and has a good application prospect in high-end electronic materials.

The application provides a reactive silicone oil and a preparation method and application thereof. The preparation method of the reactive silicone oil comprises the following steps: S1, under the protection of nitrogen, trimethyl monochlorosilane is added into a mixed solution of hydroxyl silicone oil, an acid-binding agent and an organic solvent, and reaction is carried out at 40-50 DEG C for 2-3 h, and then the reaction is cooled to room temperature; S2, methyl dichlorohydrogen silane is added into the system of step S1, and reaction is carried out at 30-50 DEG C for 2-3 h, and then the system is cooled and filtered, and the filtrate is obtained by removing low boiling; S3, under the protection of nitrogen, both end vinyl silicone oil, platinum catalyst, the product of step S2 and an additive are mixed, and reaction is carried out at 65-80 DEG C for 2-3 h, and then low boiling is removed, and the product is obtained. The reactive silicone oil obtained by the preparation method of the application is used to replace dimethyl silicone oil in the rubber compound, which can reduce the viscosity of the pouring sealant, and greatly reduces the leakage problem caused by adding dimethyl silicone oil in the prior art.

The invention provides alkoxy-terminated polysiloxane and a preparation method thereof.107 silicone rubber, a platinum catalyst and an end-capping reagent are mixed and stirred at the room temperature for a dehydrogenation reaction, and the alkoxy-terminated polysiloxane is obtained. The end-capping reagent is obtained by mixing hydrogen-containing double end caps, vinyl siloxane and a platinum complex catalyst and then reacting at the temperature of 20-35 DEG C. The preparation process of the terminated 107 silicone rubber is carried out at room temperature, the raw material cost is low, the process is simple, the condition is mild, and the method is safe and energy-saving. The prepared terminated 107 silicone rubber is colorless transparent liquid, and has the advantages of controllable viscosity, high product termination rate, no viscosity peak and good storage stability. In addition, the reaction endpoint is easy to judge, and the reaction endpoint can be determined according to whether a viscosity peak exists or not.

A preparation method of a graphite heat-conducting gasket capable of being compressed and rebounded comprises the steps that an artificial graphite film is pretreated to obtain a pretreated film, and pretreatment comprises punching, bending, surface grafting and plasma surface treatment; preparing epoxy modified polydimethylsiloxane resin according to a preset proportion; wherein the preset proportion comprises the following components in percentage by mass: 90 to 98 percent of epoxy modified polydimethylsiloxane, 2 to 10 percent of polydimethylhydrosiloxane and 0.1 to 0.4 percent of platinum catalyst; coating the surface of the pretreatment film with the epoxy modified polydimethylsiloxane resin, and carrying out die assembly on the pretreatment film with a preset number of layers to obtain blocky graphite; and slicing and post-processing the blocky graphite to obtain the graphite heat-conducting gasket. By matching the epoxy modified polydimethylsiloxane resin with a specific ratio, a stable cross-linked network structure is formed, and the structural strength and the heat conduction stability of the gasket are further enhanced.

The application discloses a bone-integrative degradable silica gel support for treating bone nonunion and a preparation method thereof, and relates to the technical field of medical implant materials.The preparation method comprises the following steps: hydrogen-containing silicone oil and allyl glycidyl ether are subjected to a hydrosilylation reaction under the action of a platinum catalyst to generate silicone oil containing an epoxy group, then the epoxy group is subjected to ring-opening under the action of a catalyst to obtain silicone oil containing a phosphate group in a side chain; carboxyl-terminated polylactic acid-glycolic acid copolymer is mixed with the silicone oil containing the phosphate group in the side chain, and a condensation reaction is carried out under the action of a condensing agent and a catalyst to obtain a PLGA-P-PDMS-PLGA triblock copolymer; the triblock copolymer, a reactive diluent, a photoinitiator and inorganic reinforcing fillers are mixed to obtain 3D printing slurry; and the printing slurry is printed into a designed bone-integrative support according to set printing parameters by using a light-curing 3D printing technology.The application endows the material with intrinsic osteogenic activity, and realizes the unification of bioactivity, shape memory function and mechanical support.

The present invention relates to silver nanoclusters doped with rhodium hydride, a method of producing the same, and an electrochemical catalyst for hydrogen gas generation. The silver nanoclusters doped with rhodium hydride of the present invention have utility as an electrochemical catalyst, have a significantly low production cost compared to a platinum (Pt) catalyst according to the related art, and exhibit an effect of generating hydrogen gas equal to or greater than that of the Pt catalyst.

The invention discloses a method for preparing highly uniform silicone elastomer gel by accurately controlling in-situ cross-linking reaction, and relates to the technical field of preparation of high polymer materials and organic silicone gel. The invention relates to a silicone sealant, which comprises the following components: a dispersion medium: 60 wt%-90 wt% of polyorganosiloxane; a first reactant: 10 wt%-30 wt% of polyorganosiloxane containing at least two aliphatic unsaturated groups in the molecule; a second reactant: 0.5 wt%-10 wt% of polyorganosiloxane, the molecule of which at least contains two silicon-bonded hydrogen atoms (Si-H); the catalyst is a platinum-based catalyst and is used for promoting the hydrogen silicification reaction. The preparation method comprises the following steps: 1, mixing a first reactant and a second reactant in a dispersion medium with the viscosity of 2-100 cSt, and removing oxygen through nitrogen substitution; and 2, adding a platinum catalyst into the mixture obtained in the step 1, and carrying out an in-situ cross-linking reaction on the polysiloxane containing the aliphatic unsaturated group and the polysiloxane containing the silicon-bonded hydrogen atom so as to directly form particles.

The invention discloses an activity recovery method for a fuel cell platinum catalyst after carbon monoxide poisoning, which comprises the following steps: periodically and alternately introducing oxidizing gas and reducing gas, and treating the anode of the fuel cell after carbon monoxide poisoning under the condition of low-temperature heating, the reducing gas is hydrogen or hydrogen-containing gas. According to the method, by controlling the switching time sequence of oxidizing gas and reducing gas, CO adsorbed on the surface of the catalyst is oxidized into CO2 and desorbed in the oxidation stage, formed Pt-O species are reduced into metallic platinum and surface residues are removed in the reduction stage, meanwhile, the surface of the platinum catalyst is induced to be dynamically reconstructed, and the surface of the platinum catalyst is subjected to dynamic reconstruction. The method has the advantages that lattice defects caused by poisoning can be repaired, the activity recovery rate of 90% or above can be achieved at the temperature of 80 DEG C, an external power source or additional complex equipment is not needed, and the method has the advantages of being easy and convenient to operate, low in energy consumption and free of influence on system operation and is suitable for online regeneration and maintenance of the proton exchange membrane fuel cell system.

The application discloses a hydrogen fuel cell parameter optimization method and device, and relates to the technical field of fuel cells.The method comprises the following steps: establishing a multi-physical field coupling model according to the microstructure and macro-variable of a catalytic layer, which is used for quantifying the influence of platinum catalyst distribution on the performance of a fuel cell; determining an anisotropic platinum distribution function based on the concentration distribution characteristics of reactants and the multi-physical field coupling model; extracting multi-physical field indexes from the multi-physical field coupling model; constructing a proxy model between the platinum distribution function and the multi-physical field indexes based on a neural network; optimizing the platinum distribution parameters based on the proxy model through a multi-objective optimization algorithm; and screening the optimal anisotropic exponential platinum distribution parameter combination through a multi-attribute decision method. Through the multi-objective optimization algorithm and the multi-attribute decision method, the key multi-physical field indexes are collaboratively optimized, the optimal platinum distribution of the current fuel cell parameters can be accurately screened, and the solving precision performance of the optimal parameters of the hydrogen fuel cell is significantly improved.

The invention relates to a high-durability fuel cell platinum-based catalyst and a preparation method thereof, the fuel cell platinum-based catalyst comprises a platinum-based catalyst and a metal oxide, and the metal oxide covers a part of the surface of the platinum-based catalyst; the metal oxide comprises an indium element. An indium oxide or an indium-containing composite oxide is modified on the surface of the platinum-based catalyst, and the oxide can be stably combined on the surface of the platinum-based catalyst to form epitaxial growth and form an interface site with the platinum catalyst, so that the fuel cell catalytic activity of the platinum catalyst can be promoted. Meanwhile, by controlling the reasonable coverage degree of the metal oxide on the surface of the platinum-based catalyst, the number of active sites exposed by the platinum catalyst is reserved, and the catalytic performance of the oxygen reduction reaction of the cathode of the fuel cell is improved to the maximum extent.

A SCALABLE MICROWAVE-ASSISTED CONTINUOUS FLOW METHOD FOR SYNTHESIS OF PLATINUM ON CARBON CATALYST AND A SYSTEM THEREOF The present invention relates to a microwave-assisted continuous flow process for synthesis of platinum on carbon catalyst with shorter residence times and providing a high throughput. Further, the present invention relates to a microwave-assisted continuous flow system comprising two or more continuous stirred tank reactors (2 and 3) connected in series and placed in a microwave oven (6) for synthesizing platinum on carbon (Pt / C). Ref. Figure 1

The invention belongs to the technical field of optical fiber sensors, and discloses a real-time temperature monitoring fault positioning high-current-carrying-capacity intelligent cable and a preparation method thereof, and a built-in optical fiber sensor comprises an optical fiber preform, a thermosensitive coating, a Kevlar fiber, a flame-retardant sheath sleeve, a Kevlar fiber and an armored loose sleeve; the heat-sensitive coating is prepared by curing a corresponding coating mother solution, and the mother solution comprises the following components in parts by weight: 30-35 parts of a heat conducting agent, 4-7 parts of hydrogen-containing silicone oil, 35-40 parts of raw silicone rubber, 10-15 parts of a heat sensitive agent, 6-9 parts of hydroxyl silicone oil, 12.5-22 parts of a cross-linking agent, 0.02-0.2 part of an inhibitor, 0.1-0.5 part of a platinum catalyst and 1-3 parts of a silane coupling agent; rigid POSS, high-degree-of-freedom long-chain polysiloxane and a free radical absorbent in the heat sensitive agent endow the optical fiber sensor with tensile property, heat resistance and high response performance, and real-time, accurate and rapid temperature monitoring is realized.