412results about How to "Improve grafting efficiency" patented technology

The invention discloses a method for preparing a lubricant coating on the surface of polymer materials of a medical catheter, which comprises the following steps: (A), pretreating the surface of the polymer materials of the medical catheter, so as to obtain hydrophilic adsorption active sites; (B), soaking the pretreated polymer materials of the medical catheter in step (A) into a prepared precursor solution of the lubricant coating for adsorption; and (C), performing grafting reaction on the soaked polymer materials of the medical catheter in step (B), and washing and drying the polymer materials of the medical catheter. The method can be widely used for preparing medical polymer materials and coating materials on the surface of a medical apparatus.

The invention discloses a linen fiber modification method, in particular to a linen fiber graft aminization modification craft, belonging to the technical field of printing and dyeing, which is characterized in that the linen fiber is selectively oxidized with oxidant solution such as sodium periodate, and oxidation linen fiber is obtained; the surface aldehyde group of the oxidation linen fiber is reacted with the surface amino of amine-terminated overbranched compound and the quaternary ammonium salt, which are combined by covalent bond, and the graft aminization linen fiber is prepared; the abundant amino, imino group and quaternary ammonium branched chain are introduced on the surface of obtained fiber, which can increase significantly the dyeing performance of linen fiber, and simultaneously increase the pliability softness, hygroscopicity and antibacterial performance of linen fiber. The linen fiber modification method has the advantages of fast reaction rate, high graft efficiency, good fastness, convenient and easy operation, realization of non-salt dyeing for linen fiber after modification treatment, environment protection, simplified normal dyeing craft and wide potential application.

A composition comprising at least one silane possessing an unsaturated organic function; at least two free radical initiators, and a process for producing silane-crosslinked thermoplastic polymers comprising providing a cross-linkable compound; at least one thermoplastic polymer; and, reacting the crosslinkable compound under reactive mechanical-working conditions and exposing the crosslinkable compound to moisture to provide crosslinked thermoplastic polymers.

The invention relates to a modification compatibilizer of PPO/PA (Poly-p-phenylene oxide/polyacrylate) alloy and a PPO/PA alloy. The compatibilizer is characterized by being a grafted copolymer of polyphenyl ether, glycidyl methacrylate and styrene; and the PPO/PA alloy with the compatibilizer is characterized by comprising the following components in percentage by weight: 50-59.5% of polyphenyl ether, 31.5-40.4% of nylon, 0.1-18% of the compatibilizer and 0.1-0.5% of antioxidant. Compared with the prior art, the prescription of the compatibilizer matching with the PPO/PA disclosed by the invention can be used for greatly improving the compatibility of the PPO/PA alloy and improving the mechanical property and water resisting property of the PPO/PA alloy and is in good condition of industrial application.

The invention discloses a method for modifying a nano metal oxide by coupling graft, and belongs to the technical field of nano granule surface modification. The nano metal oxide is used as a raw material, N,N'-carbonyl diimidazole (CDI) is used as an activating agent, and a finished product is obtained by simple processes of drying treatment, coupling reaction, separation and purification, coupling graft, re-separation and re-purification. The method has the advantages of simplicity, mild reaction conditions, high grafting efficiency which reaches 87 percent, energy conservation, emission reduction, low cost and suitability for large-scale industrial production. The nano metal oxide prepared by using the method can be widely applied in the fields of rubber, coating, ink, dye, glass, piezoelectric ceramics, photoelectrons, medicament and the like.

The invention discloses a method for preparing maleic polypropylene by supercritical reaction extrusion, wherein polypropylene, maleic series, additives and initiators are added into a screw extruder, and supercritical CO2 is injected into the system by a supercritical generation device, which makes up 0.1-20 percent of the total mass of reactant; the rotating speed of main screwed pole of the extruder is 50-600 rpm, and the extruder is divided into a plurality of heating areas, the temperature of the firs area is 180-220 DEG C, and the temperature of the other areas is 140-200 DEG C and the reaction time is 1-20 min. The grafting rate of maleic polypropylene prepared by the invention, with high grafting rate and grafting efficiency, can reach up to 1.2 percent, the grafting efficiency can reach up to 90 percent and the melt flow rate is adjustable within 5-50g/10min. The method of the invention is suitable for continuous production and has low energy consumption, and is environment-friendly. The product shows superiority in color, uniformity, processing property and mechanical property and so on, which is suitable for the fields of polymer compatilizer, adhesive and surface coating etc.

The invention relates to a method for increasing grafting efficiency for emulsion particle with acrylate being core-shell, belonging to high molecular chemical field, and especially relating to composite of high molecular compound. The polymer of acrylate core-shell employs cross-linked acrylate rubber polymer as core, the grafting rate of which is low, between 20-30%. The invention comprises following steps: preparing initiator monomer containing azo group for initiating function and polymerisable ethenyl double bond; then, preparing acroleic acid butyl seed latex at low temperature with redox initiating system, employing methacrylic acid gylcol ester or methylol propane triacrylate as crosslinking agent; finally, adding shell monomer, heating, and the azo group breaking into free radical and initiating shell monomer polymerization. The free radical is connected on main chain of polyacrylacid ester with chemical bond, which increases initiating rate; and the two ends of azo monomer is provided with polymerization double bond, which increases grafting efficiency to above 70%.

The invention relates to an ultraviolet radiation two-step grafting method on the surface of polyethylene fiber with ultrahigh molecular weight. The method comprises the following steps of: coating a photosencitizer on the surface of preprocessed polyethylene fiber with ultrahigh molecular weight; soaking the polyethylene fiber in a first grafting monomer solution; forming a surface dormant group by adopting ultraviolet radiation or direct illumination; then, soaking in a second grafting monomer solution; initiating a secondary monomer surface free radical grafting reaction by ultraviolet radiation or heating; and finally, post-processing. Compared with the prior art, the invention has the advantages that the polar group is introduced to the surface of the polyethylene fiber with ultrahigh molecular weight, the reaction is controllable, the grafting efficiency and the grafting rate are higher, the second monomer with higher reaction activity is grafted on a primary grafting basis, and the adhesive performance of a matrix and the polyethylene fiber with ultrahigh molecular weight is greatly improved.

The invention discloses a full-automatic melon stock and scion grafting machine, and aims to provide a full-automatic melon stock and scion grafting machine which is high in grafting efficiency, high in grafting quality, reliable in performance and convenient to use. The full-automatic melon stock and scion grafting machine comprises a main stander, and a stock seedling visual grading and transplanting device, an electromagnetic vibration sequencing clamp conveying device, a vibration type clamp feeding device, a stock seedling positioning and carrying device, a stock cutting device, a scion positioning and carrying device, a scion cutting device, a scion seedling taking device and a control system which are arranged on the main stander, wherein a stock seedling transplanting manipulator of the stock seedling visual grading and transplanting device is transversely arranged above a stock seedling disk conveying belt and a seedling basin conveying belt through a portal frame; a seedling basin simulation module is arranged at the piston rod end of a seedling basin pushing conveying cylinder and is opposite to a tray of the stock seedling positioning and carrying device. The full-automatic melon stock and scion grafting machine is suitable for full-automatic stock and scion grafting work of melons.

The invention provides a porous scaffold provided with a surface oriented functionally modified coating and a preparation method of the porous scaffold. The surface of the porous scaffold material structure is coated with a polydopamine coating structure, and a functional component structure layer capable of releasing drug molecules or biomolecules with bioactive function/action in a biological fluid environment is grafted in a modular way to a hydroxyl and/or amino part on the surface of the polydopamine coating structure. During preparation, firstly, the polydopamine coating is deposited on the surface of the porous scaffold; then, hydroxyl groups and/or amino groups in the surface of the scaffold material and corresponding functional components are subjected to azidation or alkynylation respectively; finally, a graft structure layer of the functional components is formed on the surface of the polydopamine coating of the porous scaffold material structure after specific azide-alkynyl modular grafting. The grafting efficiency of the functional components on the surface of the porous scaffold material is high, the grafting structure layer is firmer, the application field of the scaffold material is broadened, more function selections are provided for the scaffold material, and novel means are particularly provided for bone repair, blood vessel therapy, cancer therapy and the like.

The invention relates to an environment-friendly polyethylene compatilizer and a preparation method thereof. The environment-friendly polyethylene compatilizer comprises the following components in percentage by weight: 75 to 98 percent of polyethylene, 1 to 10 percent of functional monomer, 0.1 to 10 percent of initiator, 0.1 to 9 percent of anti-crosslinking agent, 0.1 to 3 percent of antioxidant and 0.1 to 3 percent of lubricating agent. The preparation method comprises the following steps of: placing the components in a highly mixing machine in a ratio; mixing; feeding the mixture into a double-screw extruder in a side feeding manner; extruding by using the double-screw extruder; and performing ultrasonic treatment to obtain the product. Compared with the prior art, the environment-friendly polyethylene compatilizer and the preparation method thereof have the advantages that: the polyethylene compatilizer with high grafting ratio is obtained by a compound initiating system and an ultrasonic technology; the problems of high monomer residual amount and serious gelling phenomenon are solved; emission of toxic substances is reduced; and the environment and healthiness of users are protected.

The invention relates to a preparation method of a graphene oxide modified waterborne polyurethane anti-corrosive emulsion, relating to the technical field of preparation of aqueous coatings. The preparation method comprises the following steps: firstly, mixing N,N-dimethylformamide, graphene oxide, a catalyst and glycidyl neocyanate to react to obtain modified graphene oxide; then mixing the graphene oxide, isophorone diisocyanate and polyadipic acid-1,4-butanediol ester, raising the temperature to 85 DEG Ca and then reducing the temperature to 60 DEG C; then adding dibutyltin dilaurate, 5-N-methyl pyrrolidone, epoxy resin, 2,2-dimethylolpropionic acid and trimethylolpropane to react; adding triethylamine to react at the temperature of a reaction material of 60 DEG C; then adding deionized water at 60 DEG C to react; reducing the temperature to 40 DEG C; carrying out filtration; and taking the filtered object to obtain the graphene oxide modified waterborne polyurethane anti-corrosiveemulsion. The shielding capacity of a graphene oxide sheet layer can be further improved by means of hydrophobic effect formed by a long alkyl chain grafted to the surface of graphene oxide.

The invention relates to a method for grafting pitaya with pitaya flowers as stocks. The method particularly includes the steps of selecting the pitaya flowers as stock seedlings, using pitaya branches as scions, and grafting the pitaya scions to the pitaya flowers at the right moment, wherein dipping and disinfection processing are carried out on the base portions of the scions and the cut portions of the stocks with an ABT1 solution and a carbendazim solution before grafting is carried out; after the pitaya scions are grafted to the pitaya flower stocks, smearing all exposed wounds after the butt joint with a layer of Vaseline, and finally binding the butt joint portions of the scions and the stocks through plastic wrap to fix the scions and the stocks in a coincident mode. By means of the method, due to the fact that the wild pitaya flowers have the advantages of being abundant in resource and excellent gene and the like, after the pitaya is grafted on the pitaya flowers, the pitaya fruited on the pitaya flowers is high in yield, good in taste and good in quality after grafting is carried out; meanwhile, pitaya grafting is of great significance on the effects of sustainable utilization, the low-yield improvement and waste recycling of the pitaya flower resources, the effect of rapidly enlarging the planting area of the pitaya and the like.

The invention discloses a waterborne single-component transparent anti-corrosion coating based on dual-functionalized nano-SiO2 particles and a preparation method of the coating. The dual-functionalized nano-SiO2 particles are prepared by introducing double bonds on the surfaces of nano-SiO2 particles, further grafting with di(methacryloyloxyethyl) hydrogen phosphate and a fluorine-containing monomer and simultaneously introducing phosphate groups and fluorocarbon chains on the surfaces of the nanoparticles to prepare the dual-functionalized nano-SiO2 particles; and further polymerizing the dual-functionalized nano-SiO2 particles and an emulsion to obtain dual-functionalized nano-SiO2 hybrid styrene-acrylic emulsion, so that the corrosion resistance of the styrene-acrylic emulsion system is greatly increased. Under the condition that an anti-rust pigment is not added, the emulsion can reach ISO4628-3-2003 Ri 0-level anti-corrosion standard after the emulsion is subjected to salt spray for 500 hours.

The invention discloses a method for carrying out real silk fabric anti-crease and antibacterial finishing by virtue of a laccase-TEMPO process. Quinones active groups are generated through catalyzing tyrosine residual groups in real silks by laccase so that chitosan molecules are grafted on the real silks; then 2,2,6,6-tetramethylpiperidine-nitrogen oxide (TEMPO) is added and is used for catalyzing chitosan and tyrosine in the real silks to generate formyl groups, so that the grafting amount and bonding firmness of the chitosan on the real silks are increased, and the real silk fabric anti-crease and antibacterial finishing is realized. The method comprises the following specific steps of: (1) catalytically oxidizing the tyrosine residual groups in the real silks by the laccase; (2) taking the chitosan and the quinones active groups in the real silks to react; (3) catalyzing the real silks by laccase-TEMPO to graft the chitosan; and (4) washing the real silks with water and then treating. Compared with traditional chemical cross-linking-process vacuum fabric anti-crease and antibacterial finishing, the method has the advantages that the grafting efficiency of the chitosan is high, enzyme treatment conditions are moderate, the real silk fabric anti-crease and antibacterial effect is relatively good and the strength of the fabric is improved.

The invention relates to a matching mechanism for stock seedlings and cion seedlings, aiming to provide a mechanism having the characteristics of higher automation degree, reliable property, simple structure, convenience for operation and lower cost. The invention adopts the technical scheme that the vision based matching mechanism of a fruit and vegetable grafting machine for seedling to be grafted comprises a conveying platform and a mounting frame arranged on the conveying platform, wherein the top surface of the conveying platform is provided with a conveying mechanism for conveying stock seedling hole trays or cion seedling hole trays to an operation position; the mounting frame is provided with a turntable for placing the stock seedlings or the cion seedlings, a turntable mechanism for driving the turntable to rotate, a mechanical claw for handling the stock seedlings and the cion seedlings to the turntable from the hole trays, a moving mechanism for driving the mechanical claw to move, a photoelectric sensor for detecting the positions of the stock seedling hole trays or the cion seedling hole trays and a CCD (Charge Coupled Device) camera for collecting stock seedling or cion seedling images and transmitting the images to a computer for processing; and the conveying mechanism comprises a belt wheel driven by a motor and a conveying belt which is driven by the belt wheel and horizontally arranged.

The invention provides a high-grating-rate and low-odor polypropylene resin composition and a preparation method thereof. The polypropylene resin composition consists of the following components in parts by weight: 100 parts of polypropylene resin, 1-3 parts of a polar monomer, 0.01-1 part of an initiator A, 0.01-1 part of an initiator B and 0.5-2 parts of a second monomer. The preparation method comprises the steps of weighing raw materials according to the weight part, mixing the raw materials in a high-speed mixer for 2-5min and discharging materials; and implementing reactive extrusion grafting on the mixed raw materials through a dual-screw extruder. The polypropylene resin composition disclosed by the invention, through selecting initiator and comonomer, reduces pungent odor of materials and improves grafting efficiency. The prepared polypropylene disclosed by the invention has the advantages of light product odor, high grating rate and low gel rate, and is applicable to a flexibilizer and a compatilizer of polar monomer and non-polar polymer alloy; the polypropylene resin composition is used for filling or strengthening polypropylene, and is capable of improving the mechanical performance and the heat resistance of the material.

The invention relates to a temperature-sensitive type cell culture surface and a preparation method thereof. The preparation method comprises the following steps: (1) preparing a temperature-sensitive primary liquid: adding temperature-sensitive compounds and radical initiators to solvents and stirring to dissolve the materials to obtain the temperature-sensitive primary liquid, wherein the mass ratio of the temperature-sensitive compounds to the solvents is (2-50) to 100; the mole ratio of the radical initiators to the temperature-sensitive compounds is (0.5-50) to 100; (2) reacting a cell culture surface for 5-120 minutes under the condition of 50-150 DEG C after distributing the temperature-sensitive primary liquid on the cell culture surface, thus obtaining the temperature-sensitive type cell culture surface. The preparation method has the beneficial effects that the cell culture surface with the temperature-sensitive response function can be obtained by directly initiating graft polymerization of the temperature-sensitive compounds on the cell culture surface by utilizing the common chemical radical initiators; compared with the prior art, the preparation method has the advantages that the production cost of the temperature-sensitive type cell culture surface is greatly reduced; the grafting ratio is high; the preparation method is environmentally friendly.