244results about How to "Uniform molecular weight" patented technology

The invention relates to thermosetting acrylic resin for a powder coating. The thermosetting acrylic resin is prepared from the following raw materials in parts by mass: 4-14 parts of an initiator, 110-280 parts of soft monomers, 400-570 parts of hard monomers, 192-450 parts of functional monomers, and 1-8 parts of a molecular weight regulator, wherein the soft monomers refer to acrylic acid alkyl ester compounds, and the hard monomers refer to methacrylate, styrene, or compounds of derivatives of methacrylate and styrene. The acrylic resin contains epoxy functional groups and hydroxyl functional groups simultaneously, wherein the epoxy equivalent is 570-630g/mol and the hydroxyl value is 40-50mgKOH/g; the acrylic resin can react with various substances such as carboxyl, amidogen and isocyanate and can be used for powder coating. A coating film, which is formed after the thermosetting powder coating prepared from the acrylic resin in combination with other materials is sprayed, has excellent weather resistance, good leveling performance, outstanding surface hardness, and high glossiness, durability and decorating performance; the powder coating can be used for indoor or outdoor metal sectional materials or building materials. The thermosetting acrylic resin can substitute for TGIC (triglycidyl isocyanurate) to a certain extent so as to avoid the use of the toxic substances.

Provided is a process for producing biomass-based product from straw hemicellulose and utilizing the components thereof thoroughly. Steam-explosion and acid-hydrolysis are combined in the pre-treatment of straw in the process, thus a higher concentration of a sugar liquid can be obtained, and furfural and acetic acid can be recovered. The hemicellulose obtained by the pre-treatment can be used directly as ferment materials for producing butanol, succinic acid, butylene glycol, lactic acid, hydrogen and firedamp, which reduces the cost of these biomass-based products. The cellulose and lignin obtained by extracting the straw with an alkaline solution can produce products, such as sodium hydroxymethyl cellulose etc. In the process, all components in the straw can be utilized thoroughly and waste and pollutant will not be produced.

A separatory material comprising a composite material containing a stimulus-responsive polymer and a substance interacting specifically with a target substance, wherein said stimulus-responsive polymer undergoes a structural change upon a physical stimulus so that the interaction of said substance interacting specifically with the target substance is affected by the chemical or physical environmental change, thereby causing a reversible change in the interaction force with the target substance due to the physical stimulus, which separatory material is characterized in that said stimulus-responsive polymer has no affinity with said substance interacting specifically with the target substance.

The industrial producing process of coal series needle coke includes the following steps: stepped condensing the flash oil produced in vacuum flashing of coal tar pitch to obtain three, heavy, medium and light, fractions; polycondensating the medium fraction in an improved pitch circulating process to obtain condensed pitch; delay coking the condensed pitch and the heavy fraction and injecting N2 into the un-coked oil in the later coking stage to perform the final heating and coke drawing of the needle coke forming course; and final high temperature calcining to obtain coal series needle coke. Thus produced coal series needle coke has low thermal expansion coefficient and may be used in producing high power and super high power graphite electrode.

The invention discloses a hydrogel antifouling fiber, a preparation method of hydrogel antifouling fiber and a preparation method of an implanted type high-strength hydrogel antiflouling coating layer, and relates to antiflouling materials, preparation methods of the antiflouling materials, and preparation methods of vessel antifouling coating layers, for mainly solving the technical problems that the conventional PVA (Polyvinyl Acetate) fiber implanted type vessel antiflouling coating layer is poor in antifouling effect and short in service life. The hydrogel antifouling fiber disclosed by the invention is a fiber with a core-shell structure, the shell layer of the fiber is made of polyacrylamide, and the core layer is made of carbon nano tube modified polyacrylamide. The preparation method comprises the following steps: 1, preparing polyacrylamide hydrogel, 2, preparing a core layer spinning dope, 3, preparing a shell layer spinning dope, 4, spinning by using a wet method to obtain the hydrogel antifouling fiber. The preparation of the antifouling coating layer comprises the following steps: spraying implantation gel onto a substrate, further implanting the hydrogel antifouling fiber into the substrate through a high-pressure static implantation technique, and drying to obtain the implanted type high-strength hydrogel antifouling coating layer. The coating layer is not changed when being soaked in seawater or industrial water for 6 months, so that the coating layer can be applied to vessel antifouling.

The invention relates to a preparation method and a refining method of medical hemostatic polysaccharide starch. With pretreated potato starch as a raw material and epichlorohydrin as a crosslinking agent, a microsphere adopting a three-dimensional network structure is synthesized by an emulsifying and crosslinking technology. The medical hemostatic polysaccharide starch is high in biocompatibility; the medical hemostatic polysaccharide starch is full with wrinkles on the surface, so that the particle surface area is increased, the water absorbing rate is significantly improved and the hemostatic time is greatly reduced; the medical hemostatic polysaccharide starch is especially applicable to large-area blood seepage, deep bleeding, and bleeding at a part difficult to reach by operative procedures.

The invention discloses an environmentally-friendly hot-melt pressure sensitive adhesive. The environmentally-friendly hot-melt pressure sensitive adhesive is prepared from, by weight, 25-35 parts ofa thermoplastic elastomer, 28-36 parts of modified petroleum resin, 6-10 parts of natural tackifying resin, 12-20 parts of a plasticizer, 2-3 parts of a modifying filler, 0.2-0.3 part of a coupling agent and 0.2-0.3 part of an antioxidant. The present invention also discloses preparation method of the hot-melt pressure sensitive adhesive. The thermoplastic elastomer is used as a matrix for the hot-melt pressure sensitive adhesive, the modified petroleum resin and the natural tackifying resin are used as tackifying resins, and no organic solvent is needed, so the raw materials are safe and environmentally friendly; the petroleum resin is modified, so the compatibility of the petroleum resin and the thermoplastic elastomer is improved, and the thermal stability of the hot-melt pressure sensitive adhesive is improved; and the reinforcing effect of the modifying filler improves the initial viscosity, the glass strength and the thermal stability of the hot-melt pressure sensitive adhesive are improved, so the environmentally-friendly hot-melt pressure sensitive adhesive with excellent performances is prepared.

The invention belongs to the field of medical materials and discloses a medical polyurethane adhesive and a preparation method thereof. The preparation method comprises the following steps of mixing the dehydrated polyether polyol with an amine catalyst, an organic solvent and a diisocyanate under the condition of introducing nitrogen gas and stirring, and reacting the mixture to obtain a NCO (Isocyanate)-terminated polyurethane prepolymer; adding a castor oil or a derivative thereof to the obtained NCO-terminated polyurethane prepolymer, and reacting the mixture to obtain a castor oil-modified polyurethane prepolymer solution; adding a polysaccharide substance into the obtained castor oil-modified polyurethane prepolymer solution, and reacting the mixture to obtain a polysaccharide-castoroil modified hyperbranched polyurethane prepolymer solution, wherein the polysaccharide substance is any one or more than two of maltodextrin, amylose and hyaluronic acid; after completion of the reaction, removing the organic solvent to obtain the medical polyurethane adhesive. According to the medical polyurethane adhesive and the preparation method thereof disclosed by the invention, the castor oil or the derivative thereof and the polysaccharide material are used as a bio-based polyol, and the obtained polyurethane adhesive has remarkably improved biocompatibility.

The invention relates to a preparation method for dicyclopentadiene unsaturated polyester resin which can be thickened. The method is characterized in that reaction material, namely, dibasic acid (anhydride) and deionized water are added into a reactor according to the mol ratio of 1: 1.0 to 1.2, the temperature is raised to 100 to 140 DEG C, and hydrolytic reaction is performed for 0.5 to 1h; 0.4 to 0.8 mol of dicyclopentadiene is titrated at 110 to 180 DEG C for hydrion displacement addition reaction and diolefine addition reaction, and after the titration is finished, reaction is performed again for 1 to 2h at the temperature; 0.3 to 0.7 mol of dibasic alcohol, catalyst accounting for 0.07 to 0.30 percent of the total material weight, and polymerization inhibitor accounting for 0.03to 0.07 percent of the total material weight are added, and the temperature is gradually raised to 200 to 210 DEG C for polycondensation reaction for 0.5 to 1h; after vacuum dehydration, styrene is added for dilution, and then the product can be obtained. The dicyclopentadiene unsaturated polyester resin synthesized through the multi-step synthesis method of the invention can be thickened, and the product is suitable to be used as the substrate resin for unsaturated polyester molding compound.

The invention relates to a preparation method of asphalt based carbon fiber. The method comprises the following steps that 1, catalytic slurry oil is adopted as a raw material; 2, high pressure hydrogenation pretreatment is performed, the hydrogen pressure is 12-18 MPa, the reaction temperature is 420-450 DEG C, the reaction is performed for 1-3 h, and a pretreatment product is obtained; 3, reduced pressure distillation is performed to obtain a fraction with the temperature not lower than 400 DEG C, and a co-carbonization component is added into the fraction, wherein deasphalted oil of naphthenic base vacuum residues or a 450-550 DEG C fraction in the naphthenic base vacuum fraction or a catalytic cracking slurry hydrogenation reduction product 450-550 DEG C fraction and the co-carbonization accounts for 10-45% that of the hydrogenation product component with the temperature not smaller than 400 DEG C, a co-carbonization high pressure condensation polymerization is performed, the reaction condition is an inert gas or nitrogen atmosphere, the reaction pressure is 1-6 MPa, the reaction temperature is 460-500 DEG C, and the reaction is performed for 6-8 h; 4, the pressure is decreased to the normal pressure, the negative pressure condensation polymerization is performed at the nitrogen flow rate of 6-10 L/(s.kg), the reaction temperature is 450-500 DEG C, the reaction is performed for 4-6 h, and high-quality spinnable mesophase asphalt is obtained; 5, melt spinning of the mesophase asphalt is performed to obtain the asphalt base carbon fiber.

The invention discloses alkyd resin for amino baking paint and a preparation method thereof. The alkyd resin for amino baking paint is prepared from the following components: 10 to 15 parts of dry or half-dry vegetable oil acid, 10 to 15 parts of triatomic alcohol with side chains, 5 to 10 parts of dihydric alcohol with side chains, 20 to 30 parts of phthalic anhydride, 1 to 3 parts of adipic acid, 0.05 to 0.2 part of esterification catalyst, 1 to 5 parts of dimethylbenzene, and 30 to 40 parts of organic solvent. The compositions and the proportions of the raw materials are screened through a lot of experiments, the component proportion is scientific and reasonable, and the alkyd resin for the amino baking paint has good flexibility, shock resistance, rigidity and weather resistance, and is wide in application range. The preparation method of the alkyd resin for amino baking paint is low in production cost, high in preparation efficiency, reasonable in whole process design, strong in operability and easy to implement.

The invention relates to a semi-continuous preparation method for solution of heterocycle-containing aromatic polyamide copolymer, which comprises the following steps of: dissolving p-phenylenediamine and 5(6)-amino-2-(4-aminophenyl)benzimidazole in a mixed solvent system and cooling to -20 to 10 DEG C; adding terephthaloyl chloride (TPC) with stirring to obtain prepolymer; and adding the prepolymer into a double-screw extruder and retaining in the double-screw extruder at the temperature of between 40 and 100 DEG C for 10 to 25 minutes to obtain the solution of heterocycle-containing aromatic polyamide copolymer. The double-screw extruder is taken as a main reactor, so that a reaction interface can be updated, the heat transfer problem of the system can be solved, the low-temperature solution polycondensation of the heterocycle-containing aromatic polyamide copolymer is semi-continuous, the side reaction is reduced, and the molecular weight of the polymer is effectively improved.

The invention discloses a preparation method and use of active low molecular weight fucosan. The method comprises the following steps: hydrolyzing the fucosan by using beta-galactosidase and beta-glucosaccharase to obtain an oligomerized fucosan aqueous solution with different molecular fragments; separating through an ultrafiltration membrane to obtain the low molecular weight fucosan at 5000-100000 Da. The preparation method of enzymatically preparing the low molecular weight fucosan is mild in reaction condition, strong in controllability, and high in retention rate of sulfate radicals which are the key active groups of the low molecular weight fucosan; the obtained low molecular weight fucosan has a good antibacterial effect and antibacterial stability. The prepared low molecular weight fucosan is a safe and environment-friendly product applied to antibacteria, and can be used for food fresh keeping and storage, and the use of pesticides and antibiotics is reduced so as to improve the security of the food.

The invention relates to the field for producing silicon rubber, in particular to a preparation method of sulfuration silicon rubber crude rubber with low hydroxyl value high temperature. The invention adopts the method that: firstly, all materials are dehydrated before preparation and then the polyreaction is conducted; after the catalyzer loses activity caused by decomposition, the material which can react with a SiOH group is added. The silicon rubber crude rubber prepared by the invention has narrow molecular weight distribution and extremely micro-hydroxy-terminated. The invention also discloses a double-pair screw belt scraping wall type stirrer.

The invention provides a monocomponent polyurethane coating, and relates to the field of coating. The monocomponent polyurethane coating comprises, by weight, the following components of 20 to 40 parts of diisocyanate, 40 to 65 parts of polyether, 50 to 75 parts of chlorcosane, 35 to 60 parts of chlorcosane, 20 to 50 parts of xylene, 15 to 25 parts of butyl acetate, 50 to 90 parts of padding, 10 to 20 parts of curing agent and 40 to 80 parts of catalyst. The acid value of the chlorcosane is smaller than 12 mg KOH/g, and the curing agent is a mixture of acetone-ethidene diamine condensation compound and methyl isobutyl ketone-ethanol amine condensation compound. The provided monocomponent polyurethane coating has the advantages that the curing speed is high, blistering in the crosslinking process and the storage process can be avoided effectively, and the practicability is high. The invention further provides a preparation method for the monocomponent polyurethane coating.

The invention belongs to the field of polymer materials, and in particular relates to a synthetic method of a resin using a hard melamine foam material. The method is as below: conducting a hydroxymethylation reaction on melamine and formaldehyde in with a solvent of water at the pH of 8.0-9.0 to generate polyhydroxy melamine; adding acid into the polyhydroxy melamine to adjust the pH value to 5.5-7.0, and adding alcohol to carry out a three-dimensional network polymerization. The alcohol is one or a mixture of methanol, ethanol, ethylene glycol and polyethylene glycol 400. According to the invention, the polyhydroxy melamine is added with acid and then alcohol, so that the resin gains good stability to facilitate storage and utilization. By adjusting the proportion of melamine and formaldehyde and controlling the reaction conditions, the obtained resin has uniform molecular weight. Weak acid conditions are employed to control the speed of a resin cross-linking reaction, so as to effectively prevent the problem that the resin coagulates into a block due to fast cross-linking.

The invention relates to a method for preparing organic silicone resin, in particular to a method for preparing heat-resistant organic silicone resin, wherein methyl chlorosilane monomers and phenyl chlorosilane monomers are mixed, added into a mixed solvent of PMA, BAC, toluene and anhydrous alcohol, subjected to alcoholysis and hydrolysis at a low temperature synchronously, neutralized by alkali, subjected to water scrubbing for one time, subjected to polycondensation, silanol, reflux and synthesis, and added with a polymerization inhibitor finally to prepare the heat-resistant organic silicone resin. The method solves the problems of smoke formation of the prior organic silicone resin at a high temperature and faded color of coating at a high temperature of more than 600 DEG C, and the organic silicone resin prepared by the method can be applied to prepare heat-resistant lacquer with various colors which can resist the high temperature of more than 600 DEG C and applied to manufacture open-fire coke ovens, grills, heat-insulated steelmaking furnaces, electric furnace discs, electric barrettes, non-smoking exhaust pipes and so on.

The invention provides a method for preparing polyester polyol by taking waste polyester bottles as main raw materials, comprising the step of introducing the polyols of tri(alpha-hydroxyethyl) isocyanurate, triethanolamine, sorbitol and the like and performing alcoholysis on waste polyester to prepare polyester polyol, wherein a new way for recycling polyester bottle waste materials is developed, and the reaction endpoint of the alcoholysis can be conveniently and effectively controlled by adopting a thin-layer chromatography method. The polyester polyol prepared by the method disclosed by the invention has a hydroxyl value of 150-310 mgKOH/g, a number-average molecular weight of 5000-7000 (which is measured by a gel permeation chromatography method, and with a mobile phase of tetrahydrofuran), and a molecular weight distribution index of 1.7-2.5; and the production cost is 65-80% of the production cost of the existing similar products.

A method for preparing high-branch low-aromatic oligopeptides belongs to the technical field of separation and purification. The preparation method adopting dry vegetable protein powder as a raw material comprises the following steps: preparing a vegetable protein alkaline protease hydrolysate, preparing an aromatic amino acid hydrolysate with a C end, preparing a C end-removed aromatic amino acid hydrolysate, preparing an ultrafiltration separation liquid, preparing an aromatic amino acid-removed oligopeptide solution, preparing high-branch low-aromatic oligopeptide freeze-dried powder, and preparing a regenerated macro-porous adsorption resin column to prepare the high-branch low-aromatic oligopeptides with the F value reaching up to 21-26. Macro-porous adsorption resin of a styrene-based skeleton substitutes active carbon to separate aromatic amino acids and the aromatic amino acid-containing oligopeptides, so the method has the advantages of high separation efficiency, high precision and repeated use; the method adopting various modern chemical technologies and devices has the characteristics of convenience in operation, mild conditions, energy saving and low production cost; and the method realizes full utilization of the raw material, does not generate three wastes, is a typical green production process, and is convenient for being promoted and applied.