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

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 method for preparing hexafluoropropylene oxide oligomer. Alkali-metal fluoride salt, aprotic inertia polarity organic solvents, fluorine-containing organic solvents and perfluoro(2-methyl-3-oxahexanoyl)fluoride are used for preparing a homogeneous activation initiator, the homogeneous activation initiator is used for initiating a hexafluoropropylene oxide monomer to have a polymerization reaction, and then the hexafluoropropylene oxide oligomer with a high molecular weight is obtained. Meanwhile, a part of products and related solvents are recycled, and an environment-friendly recycle production effect is achieved.

The invention discloses an extraction and preparation method of small molecular fish skin collagen peptide. The extraction and preparation method comprises the following steps: preparing raw materials, carrying out enzymolysis pre-treatment, carrying out enzymolysis treatment and the like. According to the extraction and preparation method of the small molecular fish skin collagen peptide, provided by the invention, fish skin is firstly subjected to degreasing treatment and then is subjected to the enzymolysis treatment; and in an enzymolysis treatment process, various types of different proteinases are used for carrying out enzymolysis on the fish skin, so that the enzymolysis speed can be improved, the dosage of the proteinase also can be reduced, and the yield of the small molecular fish skin collagen peptide can be effectively improved. According to the extraction method provided by the invention, modified activated carbon is used for de-coloring, the adsorption performance is excellent and enzymolysis liquid can be uniformly distributed; good de-coloring and deodorization effects can be realized under the conditions of small dosage and short time and effective components are not lost; and the extraction method has the advantages of low investment, simplicity in operation, good protein degradation effect and high yield of the fish skin collagen peptide, the industrial large-scale production is easy to realize and the extraction method has good application value and market potential.

The invention discloses an orthopaedic internal fixation fibroin component and a preparation method of the component. The preparation method comprises the steps of: 1, performing desalination by a diffusion dialysis-electrodialysis integrated technology to prepare a high-purity fibroin solution, 2, converting the fibroin solution into anhydrous fibroin by a vacuum freeze drying technology, 3, dissolving the anhydrous fibroin in hexafluoroisopropanol to form a hexafluoroisopropanol solution of the fibroin, 4, injecting the hexafluoroisopropanol solution of the fibroin into a mold to prepare a fibroin solid by a methanol treatment and airing technology, and 5, machining the fibroin solid into a bone nail and a bone plate. The orthopaedic internal fixation fibroin component prepared by adjusting molecular weight, molecular distribution, crystallization forming parameters and processing parameters has excellent mechanical strength and biocompatibility, is not required to be taken out by secondary operations, is controllable in a degradation rate and free from toxic and immunological rejection effects, and has wide clinical application prospects, and degradation products are amino acidand polypeptide capable of being absorbed by a human body.

The invention discloses a bio-based reactive polyurethane hot melt adhesive and a preparation method thereof. The bio-based reactive polyurethane hot melt adhesive comprises the following components in parts by weight: 40-80 parts of bio-based polyester glycol; 15 to 35 parts of polyether polyol; 10 to 25 parts of polyisocyanate; 0.1 to 2 parts of an antioxidant; 0.1-2 parts of a first catalyst; 0-35 parts of thermoplastic resin; 0-5 parts of a silane coupling agent; and 0-10 parts of an auxiliary agent; the bio-based polyester glycol is polyester glycol with the number-average molecular weight of 1500-5000, which is synthesized by using micromolecular diol as an initiator and carrying out random copolymerization on lactide and caprolactone under the action of a second catalyst. According to the present invention, the bio-based raw material is adopted to prepare the polyester glycol, and the polyester glycol is applied to the reaction type polyurethane hot melt adhesive, such that the high-performance environment-friendly adhesive can be green and environmentally friendly, and the advantages of good mechanical property, good bonding strength, excellent heat resistance and the like can be ensured.

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 provides a preparation combination of multivalence pneumococcal conjugate vaccine, a preparation method thereof and application in medicine preparation for preventing and treating diseases caused by pneumococcus. The invention further discloses a control method for conjugate molecular weight in the preparation combination of the multivalence pneumococcal conjugate vaccine. The seruminhibition problem in the multivalence pneumococcal conjugate vaccine is solved by the provided pneumococcal conjugate vaccine, and the immunogenicity in the preparation combination can be effectivelyimproved. The preparation method for the preparation combination of the multivalence pneumococcal conjugate vaccine can effectively control the molecular weight in the conjugate, and free protein andfree polysaccharide which do not join in conjugation can be easily removed.

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 invention provides a silane coupling olefin polymer modified porous composite material and a preparation method. A silane coupling olefin polymer has a structure shown in a formula (I) in the specification, wherein hydroxy on the surface of an inner duct of a silicon-based vesicle material is connected with the silane coupling olefin polymer; R1 is H or CH3; R2 is COOCH3, COOC4H9 or phenyl; R3 and R4 are respectively C1-C3 alkyl independently; X2 is Cl, Br and I; and m is an integer between 3 and 6. The method has the advantages that the polymer is grafted in the duct of the vesicle material in situ, so that the diameter of the macropore of the vesicle material can be effectively regulated, the microenvironment of the duct can be changed and the duct of the modified vesicle material can be endowed with certain elasticity.

The invention discloses a synthesis method of a special initiator for polyether polyol, wherein the initiator is essentially octyl phenolic resin. The method comprises: adding a certain amount of octyl phenol, a formaldehyde solution and a catalyst into a reaction kettle, mixing, stirring, increasing the temperature to 50-70 DEG C, carrying out a heat preservation reaction for 2-4 hours, increasing the temperature to 80-130 DEG C, carrying out a heat preservation reaction for 3-5 hours, and then carrying out filtering, distillation, concentration, preparation, and other steps to obtain the octyl phenolic resin solution. According to the invention, by adopting a closed pressurized reaction mode, the conversion rate of octylphenol is increased, and the molecular weight and molecular weight distribution of target resin can be effectively controlled; the recyclable solid acid is used for replacing the traditional strong acid, so that the requirement on production equipment is reduced, and the production process is simple, few in three wastes and low in pollution; and the high-boiling-point solvent oil is added to remove free phenol, so that the content of the free phenol can be effectively controlled, the molecular weight of the obtained octyl phenolic resin is 1100-1600, and the content of the free phenol is smaller than 0.5%.

A preparation method of a carboxyl alkyl type emulsion polymer is disclosed. A carboxyl strong-hydrophilic monomer and a long alkyl chain hydrophobic monomer are adopted as raw materials in the method. Polymer waterproof coating is prepared by a series of processes including dispersion pre-emulsification, constant-temperature polymerization, variable-speed stirring, and pH adjustment. Hydrogen bonds in carboxyl molecules can strengthen the internal binding force of the polymer, strong hydrophilic effect strengthens the adhesion with a matrix, the network-like binding effect of the cross-linking agent can significantly improve the mechanical properties between the polymers, and the polymer waterproof coating which is good in stability, high in adhesive force, and excellent and durable in waterproof effect can be produced.