2505 results about "Alkaline catalyst" patented technology

The heat insulating composite aerogel material consists of silica aerogel, titania as infrared opacifier and reinforcing fiber in the weight ratio of 1 to 0.1-0.7 to 0.7-3. Its preparation process includes compounding sol with silanolate, surface modifier, titanolate, alcohol solvent, acid catalyst and alkaline catalyst in certain proportion; soaking fiber felt or prefabricated fiber part in the sol; and supercritical fluid drying. The material of the present invention has high blocking effect on solid heat transfer, air heat transfer and infrared radiation heat transfer, excellent hydrophobicity, simple preparation process, low cost, mechanical strength over 2 MPa, and wide application range, and may be used in strict heat protection condition in aeronautics, astronautics, military and civil uses.

A process for producing alkyl esters useful in biofuels and lubricants by transesterifying glyceride- or esterifying free fatty acid-containing substances in a single critical phase medium is disclosed. The critical phase medium provides increased reaction rates, decreases the loss of catalyst or catalyst activity and improves the overall yield of desired product. The process involves the steps of dissolving an input glyceride- or free fatty acid-containing substance with an alcohol or water into a critical fluid medium; reacting the glyceride- or free fatty acid-containing substance with the alcohol or water input over either a solid or liquid acidic or basic catalyst and sequentially separating the products from each other and from the critical fluid medium, which critical fluid medium can then be recycled back in the process. The process significantly reduces the cost of producing additives or alternatives to automotive fuels and lubricants utilizing inexpensive glyceride- or free fatty acid-containing substances, such as animal fats, vegetable oils, rendered fats, and restaurant grease.

Simultaneous synthesis and purification of a fatty acid monoester biodiesel fuel from a triacylglycerol feedstock is described. In an exemplary method, the triacylglycerol feedstock is continuously contacted with a catalytic chromatographic bed comprising a first (solid phase) basic catalyst through a first port of a simulated moving bed chromatographic apparatus. A monohydric alcohol and optional second (mobile phase) basic catalyst is continuously contacted with the catalytic chromatographic bed through a second port and pumped in a first direction toward the triacylglycerol feedstock to contact the triacylglycerol in a reaction zone of the catalytic chromatographic bed where the fatty acid monoester and glycerol coproduct are formed. The fatty acid monoester is removed from the reaction zone through a product port of the simulated moving bed apparatus. Segments of the catalytic chromatographic bed are incrementally moved in a second direction, opposite the first direction, and the glycerol is removed from a raffinate port located opposite the product port of the apparatus.

In a method of producing a fatty acid lower alkylester according to the invention, a fat & oil and a lower alcohol are caused to react with each other in the presence of a catalyst, in which triglyceride contained in the fat & oil undergoes a transesterification. The catalyst to be used in the reaction is a solid basic catalyst consisting essentially of a potassium compound and iron oxide, of a calcium compound and iron oxide, or of a potassium compound and zirconium oxide. It is possible to produce the fatty acid lower alkylester at a high reaction efficiency by this method as well as to simplify or eliminate the need of catalyst separation and recovery processes.

An integrated process is described for producing biodiesel from oleaginous seeds, preferably castor bean seeds, comprising a transesterification reaction where the seeds themselves react with anhydrous ethyl alcohol in the presence of an alkaline catalyst. The resulting ethyl esters are then separated by decantation and neutralized and used as fuel for diesel engines, co-solvents for diesel and gasoline mixtures with anhydrous or hydrated ethyl alcohol. The solid fractions may be used as fertilizers, for feeding cattle and as a raw material for producing ethyl alcohol.

The invention provides a preparation method of a silicon dioxide super-hydrophobic thin film. The preparation method comprises the following steps of: step one. preparing alkaline colloidal sol, namely mixing orthosilicate ester, a basic catalyst, a solvent and water to prepare the SiO2 alkaline colloidal sol; step two. adding hexamethyl disilazane to the SiO2 alkaline colloidal sol for reaction to obtain modified SiO colloidal sol; and step three. coating the modified SiO colloidal sol on the surface of a substrate, and drying to obtain the silicon dioxide super-hydrophobic thin film. The invention also provides a super-hydrophobic material. The silicon dioxide super-hydrophobic thin film prepared by the method has strong adhesion force with a substrate and a good dewatering effect; complicated equipment is not needed; the process is simple; the preparation cycle is shortened; the cost is saved; and the application range is wide.

A composition for film formation capable of forming a silica-based coating film having low water absorption and dielectric constant of 2.1 or lower and useful as an interlayer insulating film material in semiconductor devices, etc. The composition contains: (A) a product of hydrolysis and condensation obtained by hydrolyzing and condensing at least one silane compound selected from the group consisting of compounds represented by formula (1), compounds represented by formula (2), and compounds represented by formula (3) in the presence of a basic catalyst and water, <paragraph lvl="0"><in-line-formula>RaSi(OR1)4-a (1) </in-line-formula>wherein R represents a hydrogen atom, a fluorine atom, or a monovalent organic group, R1 represents a monovalent organic group, and a is an integer of 1 or 2, <paragraph lvl="0"><in-line-formula>Si(OR2)4 (2) </in-line-formula>wherein R2 represents a monovalent organic group, <paragraph lvl="0"><in-line-formula>R3b(R4O)3-bSi-(R7)d-Si(OR5)3-cR6c (3) </in-line-formula>wherein R3 to R6 may be the same or different and each represents a monovalent organic group, b and c may be the same or different and each is a number of 0 to 2, R7 represents an oxygen atom, a phenylene group, or a group represented by -(CH2)n-, wherein n is an integer of 1 to 6, and d is 0 or 1; (B) a compound compatible with or dispersible in ingredient (A) and having a boiling point or decomposition temperature of from 250 to 450° C.; and (C) an organic solvent.

The present disclosure relates to a polyimide-graphene composite material and a method for preparing same. More particularly, it relates to a polyimide-graphene composite material prepared by adding modified graphene and a basic catalyst during polymerization of a polyimide precursor so as to improve mechanical strength and electrical conductivity and enable imidization at low temperature and a method for preparing same.

The invention provides a preparation method for phenolic adhesive based on lignin phenolization liquid and application thereof. Under the condition of normal pressure heating or thermalcatalysis, phenol is taken as liquefaction reagent, lignin is added, the temperature is raised to 90 to 150 DEG C, the thermal insulation liquefaction reaction is made to cool to obtain a lignin liquefaction product; basic catalyst and formaldehyde are directly added into the liquefaction liquid, the temperature is raised to 70 to 97 DEG C under normal pressure to react for 1 to 3 hours, the reaction is terminated when the viscosity is measured to meet the preset requirement, and low-free formaldehyde environmental protection type phenolic adhesive based on lignin phenolization liquid is obtained. The adhesive obtained by the invention has lower cost and lower content of free formaldehyde than the prior phenolic resin adhesive. The plywood pressed by using the adhesive obtained by the invention has good bonding performance.

A silicon-containing film is formed from a heat curable composition comprising (A-1) a silicon-containing compound obtained by effecting hydrolytic condensation of a hydrolyzable silicon compound in the presence of an acid catalyst and removing the acid catalyst, (A-2) a silicon-containing compound obtained by effecting hydrolytic condensation of a hydrolyzable silicon compound in the presence of a basic catalyst and removing the basic catalyst, (B) a hydroxide or organic acid salt of lithium, sodium, potassium, rubidium or cesium, or a sulfonium, iodonium or ammonium compound, (C) an organic acid, and (D) an organic solvent. The silicon-containing film allows an overlying photoresist film to be patterned effectively.

The invention discloses a method for preparing a perdurable hydrophilic polyether modified amino-polysiloxane softener. The method is characterized by comprising the following steps: octamethylcy-clotetrasiloxane and amino silane coupling agents with different structures are used as raw materials; with a bulk polymerization method, under the analysis of an alkali catalyst, firstly, an amino organic polysiloxane softener with high ammonia value is generated through ring-opening polymerization; and secondly, on the basis of the amino organic polysiloxane softener, amidogen is subjected to etherifying modification, thereby synthesizing the hydrophilic polyether modified amino-polysiloxane softener with good hand feeling and hydrophilic property. The prepared softener keeps the hydrophilic property and simultaneously improves the softness of hydrophilic silicon oil so that the hand feeling of textile can reach the hand feeling of the prior linearity amino silicon oil after the textile is treated by the softener and the treated textile can keep the hydrophilic property permanently.

A process for synthesizing polyol fatty acid polyesters comprising the steps of (1) mixing ingredients comprising (a) unesterified first polyol having hydroxyl groups, (b) second polyol esterified with fatty acids, (c) basic catalyst, and (d) emulsifying agent to form a mixture of ingredients; (2) reacting the mixture of ingredients at a temperature sufficient to obtain a transesterification reaction products and by-products; and (3) removing at least a portion of the by-products from the transesterification reaction mixture; and (4) further heating the transesterification reaction products and ingredients from step (3) at a temperature and for a time sufficient to esterify at least about 50% of the hydroxyl groups of the first polyol.

A process for preparing high-granularity Si sol includes such steps as heating the SiO2 dispersed water, stirring while adding alkaline catalyst and metallic Si powder, hydrolytic reaction at pH=7-14 to obtain active silicic acid micro-particles, and quickly adsorbing the micro-particles by SiO2 seed particles to become target sol. Its advantages are high speed and controllable and uniform granularity.

The invention discloses an ambient pressure drying method for rapidly preparing SiO2 aerogel. Part of an alcohol solvent is replaced with a solvent with low surface tension; silica-alkoxides, the non-replaced alcohol solvent, an acidic catalyst, a basic catalyst and the solvent with the low surface tension are prepared into sol according to a certain proportion, after alcogel containing the solvent with the low surface tension is formed, ageing and surface modification processes are carried out, and then, ambient pressure drying is directly carried out, so that the complex solvent exchanging step is omitted, and the SiO2 aerogel is prepared within 30h. By using the method, not only are the defects such as high equipment investment, low efficiency, high cost of the traditional supercritical drying process overcome, but also the problems of long period, high using cost for solvent exchanging and the like in the traditional ambient pressure drying process are solved, and the prepared SiO2 aerogel has the characteristics of low surface density, large specific area, large pore volume and the like.

An electric double-layer capacitor comprising an electrode containing an activated carbon, an electrolytic solution containing an electrolyte and a separator, wherein the electrolyte is an imidazolium salt represented by the following formula (1)

(wherein R and R′ each independently represent alkyl group having 1 to 6 carbon atoms, R¹ to R³ each independently represent hydrogen atom or alkyl group having 1 to 6 carbon atoms and X⁻ represents a counter ion), and

the activated carbon is produced by carbonizing an organic aerogel obtained by polymerizing a phenolic compound having at least one hydroxyl group in its molecule with an aldehyde compound in an aqueous solvent in the presence of a basic catalyst.

A catalytic process for converting biomass-derived carbohydrates to liquid alkanes, alkenes, and/or ethers is described. The process uses combinations of self- and crossed-aldol condensation reactions, dehydration reactions, and hydrogenation reactions, over specified metal-containing catalysts, to yield alkane, alkene, and ether products from carbohydrate reactants.

The invention discloses a high-bonding-strength and high-temperature-resisting phenolic resin modified polyurethane adhesive and a preparation method thereof. The preparation method comprises the following steps of: synthesizing modified phenolic resin, preparing polyurethane prepolymer, synthesizing modified polyurethane prepolymer, and synthesizing the modified polyurethane adhesive, wherein the step of synthesizing the modified phenolic resin is carried out by adding methoxyl dimethylbenzene monomer and phenols in phenolic resin to react under the effect of an acid catalyst, cooling the mixture, and then adding a basic catalyst, solvent and formaldehyde in the mixture for dehydration reaction under vacuum until the mixture is transparent, thus obtaining the modified phenolic resin; the step of preparing the polyurethane prepolymer is carried out by adding polyisocyanates and polyester polyol in the modified phenolic resin for reacting; the step of synthesizing the modified polyurethane prepolymer is carried out by modifying the polyurethane prepolymer through the modified phenolic resin to obtain the modified polyurethane prepolymer; and the step of synthesizing the modified polyurethane adhesive is carried out by adding water to the modified polyurethane prepolymer, and dispersing the modified polyurethane prepolymer through dispersing agent, and finally adding neutralizing agent, cross-linking agent and chain extender into the dispersed modified polyurethane prepolymer to obtain the modified aqueous polyurethane adhesive. The preparation method disclosed by the invention is simple, and improves the bonding strength and high temperature resistance of the polyurethane adhesive.

The invention belongs to the field of advanced nano composite materials, and relates to a magnetic polymer/carbon-based microsphere material with a core-shell structure and a preparation method thereof. The preparation method comprises the steps of: by adopting a sol-gel chemical synthesis method, in an alcohol water phase, in the presence of an alkali catalyst, wrapping polymer resin macromolecule layer outside a magnetic nano particle to obtain a magnetic macromolecule microsphere with a core-shell structure, carbonizing the polymer resin macromolecule layer through high temperature roasting to obtain a magnetic carbon-based microsphere material with the core-shell structure; adding a macromolecule surfactant during preparation, removing a surfactant by carbonizing through roasting to obtain a magnetic carbon-based microsphere material with a cavity, which is of a core-shell structure. The composite microsphere has stronger magnetic responsiveness, and the surface of the composite microsphere can be further functionalized and a large quantity of hydrophobic substances are absorbed; the magnetic microsphere material with the cavity, which is of a core-shell structure, can be used in a nano reactor, drug sustained release, and large-capacity adsorption and separation. The preparation method is simple, is easily available in raw materials, and suitable for amplified production.

The invention provides a method for preparing thermoset phenolic resin and a method for preparing conductive slurry. The method for preparing the thermoset phenolic resin comprises the following steps of: firstly weighing phenol, a part of methanal, and a mixed alkaline catalyst and reacting for several hours in a reaction flask at 50-90 DEG C; adding the residual methanal to the reaction flask to react; adding acid for neutralizing, and carrying out extraction separation; heating and vacuumizing for removing agents, adding an organic solvent for dissolving to obtain a thermoset phenolic resin solution. According to the method for preparing the thermoset phenolic resin, with the mixed alkaline as a catalyst, backflow reaction is performed for a period of time and then the acid is added for neutralizing; then the organic solvent with very low water solubility is added to carry out extraction separation; then, the solvents are removed in vacuum by heating; and finally the organic solvent is added for dissolving to obtain the thermoset phenolic resin solution with a certain solid content. In addition, a conductive filler, organic diluent and other additives are added to the prepared thermoset phenolic resin solution at the same time to obtain the low-temperature conductive slurry which has the advantages of high conductivity, extremely high adhesion strength and stable electric performance and is suitable for screen printing.