30results about How to "Effective control of molecular weight" patented technology

The invention discloses a preparation method of a beaded nanofiber, and belongs to the field of preparation of nanofibers. The method comprises the following steps: firstly, grafting functional groups on inorganic nanoparticles; grafting a high-molecular polymer on the surfaces of the functional inorganic nanoparticles by a chemical polymerization method; and finally, preparing the beaded organic / inorganic nanoparticle fiber by adopting an electrospinning technique. The nanofiber prepared by the method has the advantages that the fiber structure is controllable, the nanoparticles are evenly dispersed in the fiber, the nanoparticle and the polymer interfaces are well combined and the like, the problems that positions of the inorganic nanoparticles are uncontrollable, the nanoparticles are seriously agglomerated, interface combination between an organic phase and an inorganic phase is poor and the like in an organic / inorganic nanoparticle fiber prepared by adopting the traditional method are solved, and a new idea and a new method are provided for preparation of the nanofiber containing the inorganic nanoparticles.

The invention discloses a preparation method of shock-resistant vinyl chloride copolymer resin. According to the preparation method, a polymerization method is optimized by optimizing polymerization reaction influencing factors such as the polymeric monomer formula, the dispersant formula, the polymerization reaction temperature and time and the adding mode. A product processed from the vinyl chloride copolymer resin prepared through the preparation method has excellent processability, barrier performance, flame retardance and shock resistance, is widely applied to the fields of buildings, packages, automobiles, the food industry and the like and has good market prospects.

The invention discloses a method for preparing low-molecular-weight guar gum, which comprises the following steps: irradiating guar gum hydrosol with 200-450-nanometer ultraviolet light; and obtaining solid low-molecular-weight guar gum through freeze-drying, spray drying or ethanol precipitation filtration drying. The method can obtain an oligosaccharide (a polysaccharide consisting of 2 to 10 sugar units), has the advantages of simplicity, convenience and quickness, high yield, easily-controllable molecular weight, good reproducibility, simple process equipment, safety and no pollution, lowcost and the like, and can be applied to rapid preparation of a small amount of low-molecular-weight guar gum, and can be further industrialized and applied to the production of a large amount of low-molecular-weight guar gum. The obtained product can be used for the production of foods and health products, and can also be used as medicine and chemical raw materials.

The invention discloses a dissolving pulp sodium lignosulfonate dispersant, and a reducing preparation method and application thereof. Based on a concentrated dissolving pulp waste liquid, the lignose activity is improved under the action of a catalyst, then subjected to sulfomethylation reaction, subjected to reducing reaction to obtain a brownish-black or dark brown liquid, and subjected to spray drying to obtain a dark brown or nut-brown powdered sodium lignosulfonate dispersant, wherein the weight-average molecular weight Mw is 6000-40000, and the number-average molecular weight Mn is 3000-20000. The product can be widely used for concrete admixtures, dye dispersants and coal water slurry additives; each property of the product can meet the related quality standard requirements; and the product has the advantages of simple preparation process, moderate conditions, conventional equipment, low production cost and no emission of three wastes in the production process, and can achieve the purpose of changing wastes into valuables, thereby having popularization and application values.

The invention discloses a preparation method of a cationic plugging agent for a drilling fluid. The cationic plugging agent is prepared by emulsion polymerization from raw materials in parts by weight as follows: 30-90 parts of styrene, 5-75 parts of butyl acrylate and 15-75 parts of dimethyl diallyl ammonium chloride. Monomers are initiated by an initiator to be subjected to a polymerization reaction, and the cationic plugging agent with the macromolecular chain is obtained; with addition of a small quantity of the product to the drilling fluid, the filtration loss of the drilling fluid and the invasion depth in the sand bed can be effectively reduced, plugging of underground pore cracks is realized, and drilling safety is guaranteed.

The invention relates to a biomass-based dispersant prepared by using landfill leachate and a method for preparing the biomass-based dispersant and application of the biomass-based dispersant. The method comprises the following steps: adding pulping black liquor into condensed original liquor of leachate of a comprehensive garbage disposal plant for ultrasonically homogeneous mixing; accelerating a sulfomethylation reaction through catalyst activation to obtain dark grey or brownish black liquid; and spraying and drying the liquid to obtain a deep brown or dark grey powdery dispersant, wherein the weight-average molecular weight (Mw) of the dispersant is 5000-45000 and the number-average molecular weight (Mn) of the dispersant is 2800-22000. The product is widely applied to the fields of ceramic additives, coal-water slurry dispersants and the like. Through detection, the indexes of the product meet related quality standard requirements. The production process is simple, the condition is mild, and waste is turned into wealth through conventional industrial equipment and low-price raw materials, and moreover the production process is free of three-waste discharge, so that the dispersant has wide promotional and application values and social meanings.

The invention relates to the field of synthesis and preparation of high polymer materials, and provides a grafted copolymer, a grafted copolymer / silver nanocomposite and a preparation method thereof.According to the grafted copolymer, polyvinyl alcohol or an ethylene-vinyl alcohol copolymer is adopted as a main chain, and polyisobutene is adopted as a branch chain; the main chain and the branch chain are in keyed joint in a grafted mode; the absolute weight-average molecular weight of the grafted copolymer ranges from 80 kg / mol to 700 kg / mol, and on the basis that the total mass of the grafted copolymer is 100%, the mass percentage content of polyisobutene as the branch chain ranges from 15% to 95%, and the grafting density ranges from 0.2% to 19%. According to the grafted copolymer, thegrafted copolymer / silver nanocomposite and the preparation method thereof, the number of the branch chain and the molecular weight of the branch chain are effectively controlled, the water contact angle of the composite ranges from 28 degrees to 110 degrees, the hydrophily / hydrophobicity is adjustable, and the antibacterial property, the biocompatibility and cell nontoxicity are achieved.

The present invention provides a mononuclear vanadium complex shown as formula I, and also provides a preparation method and application of the complex. The mononuclear vanadium complex has the advantages of simple preparation method, low toxicity, high catalytic activity and narrow molecular weight distribution; and the method can effectively control the molecular weight of the polymer according to the needs, and has a broad market prospect.

The invention discloses a textile assistant for sizing textiles and a preparation method thereof. The textile assistant comprises 50-200 parts of lignin, 50-200 parts of water-soluble monomer, 50-200 parts of oil-soluble monomer, 1-50 parts of water-soluble initiator, 0.05-5 parts of oil-soluble initiator, 400-1600 parts of water, 10-50 parts of dispersing agent, 500-2000 parts of low-viscosity starch with water content of 2-4%, 50-100 parts of alkaline matter and 1-30 parts of antifoaming agent. The preparation method comprises the following steps: putting matters with formulation dosages in a reaction kettle for reacting, and uniformly mixing an obtained grafted copolymer with the low viscosity starch, the alkaline matter and the antifoaming agent in a mixing machine so as to obtain the textile assistant. By adoption of the invention, the environmental load is beneficially reduced, the production efficiency is improved, the production cost is beneficially lowered, the adhesive power is proper and the serosa flexibility is good.

The present invention provides a binuclear vanadium complex shown as formula I, and also provides a preparation method and application of the complex. The binuclear vanadium complex has the advantages of simple preparation method, low toxicity, high catalytic activity and narrow molecular weight distribution; and the method can effectively control the molecular weight of the polymer according to the needs, and has a broad market prospect.

The invention discloses a preparation method for a modified aniline terpolymer / water-based resin composite anti-corrosive coating. The method comprises the following steps: a microemulsion polymerization method is adopted, aniline, o-hydroxyaniline and p-phenylenediamine are used as monomers, APS (ammonium persulfate) is used as an oxidant, and therefore an aniline-o-hydroxyaniline-p-phenylenediamine terpolymer with good water dispersibility is prepared under the action of an acid dopant and a surfactant having a sulfonic acid group; and water-based alkyd resin is used as a substrate, a modified polyaniline aqueous dispersion liquid is used as an additive, a mixed manner of ultrasonic treatment and mechanical stirring is utilized, and therefore the water-based alkyd resin / polyaniline composite heavy anticorrosive coating is prepared. The preparation method disclosed by the invention has the advantages of being friendly to the environment and convenient to operate, and having no pollution and low costs; and the prepared modified aniline terpolymer can also be compounded with other water-based resin substrates such as water-based epoxy resin, water-based polyurethane resin and water-based polyacrylate resin to prepare the composite anticorrosive coating.

The invention discloses a method for preparing biodiesel by high-acid value grease. The method comprises the following steps: dropwise adding plant or animal grease the acid value range of which is between 20 and 200mgKOH / g into a reaction kettle; carrying out catalytic cracking in a stirring state; adding sodium carbonate catalyst into the reaction kettle in advance, wherein the temperature in the reaction kettle is 450 DEG C; leading the generated cracking oil steam to pass through a rectifying column with the temperature of 320-360 DEG C and then charging the cracking oil steam into a reverse flow reaction packing tower from top to bottom; meanwhile, charging alcohol steam into the reverse flow reaction packing tower from bottom to top to carry out reverse flow reaction with the cracking oil steam; loading a bed layer of an acidic particle catalyst fixed bed into the reverse flow reaction packing tower with the temperature of 60-200 DEG C and obtaining the product biodiesel at the bottom of the reverse flow reaction packing tower. The product has the density of 0.80-0.86g / cm3, the water content of 0.31-0.39 percent, a heat value of 41.0-45.0kJ / g, the viscosity of 2.5-3.5mm2 / s, a cold filtering point of minus 8-minus 22 DEG C, a condensing point of minus 30-minus15 DEG C and an acid value of 1.0-5.0mgKOH / g. The method has simple process, low fuel acid value of the product and high conversion rate of the product.

The invention provides a silane coupling olefin polymer modified porous composite material and a preparation method. The silane-coupled olefin polymer has the structure of the following formula (I), and the silane-coupled olefin polymer is connected to the hydroxyl group on the surface of the inner pore of the silicon-based vesicle material; wherein R1 is H or CH3, and R2 is COOCH3, COOC4H9 or phenyl; R3 and R4 are independently C1-C3 alkyl; X2 is Cl, Br, I; m is an integer between 3 and 6; The branched polymer can effectively regulate the pore size of the macropores of the vesicle material, change the microenvironment of the channel, and also endow the channel of the modified vesicle material with a certain "elasticity".

The invention relates to the field of polymers, in particular to a bismaleimide polymer and a preparation method thereof. The preparation method uses bismaleimide monomer and barbituric acid or its derivatives as raw materials to carry out polymerization reaction in a mixed solvent of good solvent and poor solvent to obtain bismaleimide polymer The mass ratio of described good solvent and poor solvent is (0.01-100):1. The process provided by the invention not only has a simple method, but also reduces the pressure of solvent recovery, saves costs, and is beneficial to popularization and application. Moreover, through the combined optimization of the used solvent and condition parameters, the molecular weight of the prepared polymer can be effectively controlled to ensure that the Mw range of the prepared bismaleimide polymer is 10,000-1,000,000.